Basics of Explosion Protection - Bartec

Basic concepts for explosion protection
A leading position for safety engineering

The BARTEC company
Reinhold A. Barlian founded the BARTEC company in 1975 and creates
the corporate philosophy:
BARTEC protects people and the environment
by the safety of components, systems and plants.
Safety engineering
We are full of ideas for new products. For ever new applications, for
new markets. Thus within a space of 30 years, we have acquired a leading
position among safety engineering suppliers with our innovative
components and systems tested to international standards.
We design and build components and systems for machine and
equipment constructors and for original equipment manufacturers; for
constructors and operators of industrial plant, for the chemical,
petrochemical, pharmaceutical, power generation and environmental
engineering industries.
Expertise and reliability build the foundations of an efficient
partnership for:
Machine and equipment construction
Original equipment manufacturers
Constructors and operators of plant in the chemical,
petrochemical pharmaceutical, power generation and
environmental engineering industries
They all rely on BARTEC as an expert partner in matters of safety
engineering.
Reservation
Technical data subject to change without notice. No claims for damages arising from alterations, errors or misprints shall be allowed. Attention is drawn
to the applicable standards and regulations on safety components and systems together with the relevant operating and installation instructions.
BARTEC brochure Basic concepts for explosion protection - 5. revised edition - Version 2005 - Author: Dr.-Ing. Hans-Jrgen Linstrm
Content
Technical development of explosion protection
Explosion protection
Explosion
Basis for an explosion
Explosion range
Prevention of explosions
Primary explosion protection
Three factors
Combustible substances
Oxygen
Ignition sources
4 - 10
4
4
4
5
5
6
6
7
8 - 10
Protection principles
11 - 22
Overview
Non-technical measures
Design regulations
Regulations
Relevance and advantage of the classification in zones
Explosion engineering parameters
Ignition temperature - temperature class
Examples of the ignition temperatures of different types of dust
Minimum ignition current ratio - Maximum experimental safe gap Explosions Sub-group
Types of protection
General requirements
Flameproof enclosure
- Protection by enclosure
- Enclosed break device
- Non-incendive component
Pressurized apparatus
- n-pressurization
Powder filling
Oil/ Liquid immersion
Increased safety
- Non sparking device
- Constructive safety
Encapsulation
- Hermetically sealed device
- Encapsulated device
- Sealed device
Intrinsic safety
- Inherent safety
- Energy limited circuit
Restricted breathing enclosure
Protection by control of ignition sources
Marking
Contents of the marking
-Conformity
EC directives
Directive 94/9/EC
Directive 1999/92/EC
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13 - 16
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20
21 - 22
23 - 32
EEx d
EEx tD
EEx nC
EEx nC
EEx p, Ex pD, EEx p
EEx pz
EEx q
EEx o, Ex k
EEx e
EEx nA
Ex c
EEx m, Ex mD
EEx nC
EEx nC
EEx nC
EEx i, Ex iD
Ex g
EEx nL
EEx nR, EEx fr
EEx b
23
24
25
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26
27
27
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33 - 36
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37 - 46
37 - 42
43 - 46
1
Technical development
Technical development of explosion protection

In the 19th century, electrical equipment was introduced into industry and households. Immediately
afterwards, because of the methane and coal dust occurring in coal mines, the basics of electrical
explosion protection were developed. The advantages of electricity were so convincing, that intensive
work was carried out to find the means of reliably preventing contact between a potentially explosive
atmosphere and ignition sources - originating from the use of electrical equipment - and thus preventing
explosions.
Manufacturer
Legislative
Design regulations
Design regulations
After bitter experiences in the beginning, mine explosions were able

to be made very much rarer, and well-monitored electrical equipment
was utilised with very high safety standards.
Today, fortunately, the number of accidents caused by electrical

ignition sources is low, the development and manufacturing
expenditures as well as the legal regulations have proven
themselves.
Therefore, the frequently asked questions as to "whether the
expenditures are justified" must be answered with yes. There are
still numerous examples of explosions which demonstrate the
devastating effects for humans and plants. Any neglect would equal
culpable carelessness.
All those involved

Personal responsibility
and precautionary measures
User
Directives
Priority over the solutions referring to the ignition source is given

to primary explosion protection, i. e. the use of non-flammable
materials which cannot form a potentially explosive atmosphere is
focused on.
However, it is not always possible to exclude flammable material such as methane or coal dust in
mines, or petrol, and in the future maybe hydrogen, in vehicles. Protection and safety are in such
cases provided by equipment which is reliably protected against explosions.
These days, the construction of explosion-protected equipment has long left electrical engineering.
As will be demonstrated by further descriptions, in the future non-electrical equipment will also require
testing or at least assessing. Here the knowledge about the explosion protection of electrical equipment
that manufacturers have collected over the decades is particularly important, and now it also benefits
the manufacturers of non-electrical equipment. Often these manufacturers buy in electrical goods,
therefore a contact can easily be made.
There are many applications which require explosion protected equipment. During the over 100 years
of electrical explosion protection, principles and techniques have been developed which allow the use
of electrical measuring technology, even where, e. g. in reaction vessels, an explosion hazard is
permanently present.
Mining applications were only the beginning. The utilisation and processing of mineral oil and natural
gas offer a wide scope for the utilisation of explosion protected equipment. Organic chemistry, the
paint industry and the pharmaceutical industry all process flammable liquids and gases. Because of
the production and utilisation of biogas and the ecological utilisation of waste dumps, new applications
constantly are developing. The utilisation of hydrogen is being intensively discussed and practised in
experimental installations and exhibited at trade fairs.
Technical development
Internationally unified design regulations for electrical engineering have been drawn up in the form of
IEC standards and reports have been formulated, largely in agreement with those in the CENELEC
standards. Presently, the numerical sequence between IEC, CENLEC and DIN is being standardised.
This conversion currently results in various continuous changes, will, however, simplify future work.
The European Community has provided itself with an obligatory, uniform design requirement for the
explosion protection of systems, devices and components with the Ex directive 94/9/EC, which is
supported by the EN standards mentioned above and the CENELEC and CEN standardisation
organisation.
With the help of these standards, the manufacturer is safe to assume during the design and assessment
of the explosion protection, that he is developing safe, explosion protected systems, devices and
components conforming to the Ex directive 94/9/EC, which will be tested by applying uniform and
obligatory criteria in an authorised EC test centre. The EC authorised test centres provide a manufacturerindependent EC prototype certification which guarantees a uniform quality throughout, with regard to
the required safety of the explosion protected equipment, at a very high or enhanced safety level.
These EC prototype certificates, or assessments provided by the manufacturer, are the prerequisite for
the production and distribution of systems, devices and components at a very high or enhanced safety
level.
Constant, uniform quality requirements are, according to Ex directive 94/9/EC, also required for the
type of the installation and for the servicing required for maintaining the safe state. The technical
parameters are also defined in EN standards.
Uniform classification of the explosion-hazard equipment is the basis for the selection and classification
of systems and devices, including their installation. The appropriate EN standards are being developed
and passed step by step as directive 1999/92/EC is becoming adopted. According to this EC directive,
an Ex document is the precondition for setting up and operating an explosion-hazard facility. Only
such a document makes it possible to select and install, operate, maintain and eventually repair it as
required by the standard systems, devices and components.
The implementation of the directives will be realised in the form of national regulations, in Germany,
for example, by means of the "Gertesicherheitsgesetz" (device safety law" and the "Betriebssicherheitsverordnung" (occupational safety regulations). The 94/9/EC directive formulates consistently binding
requirements, while the national implementations of the 99/92/EC directive contains the minimum
requirements, which may be nationally more stringent.
Using the two EC directives mentioned above, a consistent system is created which allows successful
prevention of explosions for the effective protection of people, the environment and property.
BARTEC develops and constructs safety engineering systems, devices and components, develops
solutions and projects and realises them.
Our corporate goal is:
BARTEC protects people and the environment

by the safety of components, systems and plants.
Explosion
An explosion is defined as a sudden reaction involving a rapid
physical or chemical oxidation reaction or decay generating an
increase in temperature or pressure or both simultaneously. The
most familiar reactions are those of flammable gases, vapours or
dust with the oxygen contained in the air.
oxygen
Explosion
Basis for an explosion

As a rule, for explosions to happen in atmospheric air, three factors
have to be present at the same time:
flammable substance
ignition source
flammable gases
oxygen (air)
source of ignition
In production and work areas an increased risk of explosion can develop wherever the first two
preconditions for an explosion are fulfilled. Typical explosion-hazard areas form in chemical factories,
refineries, enamelling plants, paint workshops, cleaning equipment, mills and stores for milled products
and other combustible dust, in tank facilities and loading areas for flammable gases, liquid and solids.
The first two components - the flammable substance and air - must be present in sufficient quantities
to form a potentially explosive atmosphere. The statutory definitions of explosion protection - deduced
from the health and safety at work regulations - are concerned with workplaces. For this reason
discussions about explosion protection are usually restricted to reactions with the oxygen in the air.
Oxidation reactions normally involve the release of heat and a pressure increase, and therefore fulfil
the criteria of an explosion.
It is generally assumed that a volume of 10 l of a potentially explosive mixture in an enclosed space
can cause damage - particularly to people. For this reason, any area in which such a volume of a
potentially explosive mixture can collect is described as an explosion hazard zone.
Other compounds such as chlorine in reaction with hydrogen are also capable of forming potentially
explosive mixtures and have already led to explosions in the past. However, as these reactions usually
take place inside containers or reactors, they concern the safety of these facilities and their effects on
the environment are therefore dealt with in the EC machinary directive and incident analysis.
Explosion range
In the internal combustion engine the three components work together in a sensible way: petrol, air/
oxygen and the ignition spark produce an explosion inside the enclosed cylinder. For this to take
place the ratio of petrol to air must be correct. If the petrol tank is empty, the air filter is blocked or if
the ignition does not work, one of the components for triggering this controlled, useful explosion is
missing and the motor will not start.
Combustible materials mixed with air have a lower and an upper explosion limit, between these limits
the explosion range is found. When considering the safety of workplaces, the lower explosion limit is
the more important value, a possible concentration of at least 20 % less than that value is often
regarded as safe.
4
Prevention of explosions
Explosion protected equipment is able to exclude one of the preconditions for an explosion - the
ignition source - and is in that way an important contribution to explosion protection.
In domestic areas, constructional measures ensure that normally an explosive atmosphere cannot
form. The conscious restriction of these measures, e. g. the intended, unimpeded flow of flammable
gases or a reduction in ventilation can lead to explosion if an ignition source is also present.
The easiest and simplest way to understand small and safe explosions is by looking at a gas lighter.
When the nozzle of the lighter is opened it releases a small amount of flammable gas. This gas mixes
with the surrounding air, the spark from the flint ignites the mixture, and a weak sound is heard - the
burning.
Some distance away from the nozzle the proportion of the flammable gas is already so low that the
explosion and the flame are restricted to the immediate vicinity of the nozzle. In other words, the
design of the gas lighter has ensured that it is safe to use.
The effect of an explosion in enclosed spaces and under non-atmospheric conditions - e. g. under
increased pressure - is often more powerful. Just think of the useful application of explosions in
vehicle engines.
Effective preventive explosion protection for non-controlled, unintended and therefore very damaging
explosions can only be achieved by removing one of the three components.
BARTEC products prevent the occurance of ignition sources or the formation of such sources where
electricity is being used in a potentially explosive atmosphere, and in that way they are effective at
preventing explosions, because the other components - at workplaces the oxygen in the air and often
the flammable substance - cannot be reliably and permanently excluded.
Primary explosion protection

Primary explosion protection aims at substituting something else for the flammable substances or the
atmospheric oxygen or reducing their quantities to the point where there is no danger of a potentially
explosive mixture forming.
Increased air circulation, air flushing, through ventilation can be achieved by structural measures; e.g.
the open layout of filling stations where the explosion hazard area is very small.
Replacing the atmospheric oxygen is not an option for areas where people work. For this reason the
measures available for such locations are limited to:
avoidance or restriction of flammable substances which are capable of forming a potentially
explosive atmosphere
avoidance or restriction of release of the flammable substances and therefore formation
of potentially explosive mixtures, both inside and around fittings, e. g. by
- limiting their concentration
- using enclosures filled with an inert substance
- natural or artificial ventilation
- concentration monitoring by means of a gas detection system,
which will give an alarm/or switch off the system
Three factors
Flammable substances
Flammable substances can be gaseous, liquid or solid. For a general discussion relevant to workplaces,
their reactivity with atmospheric oxygen is considered.
Hydrogen
Flammable gases
A flammable gas may be an element such as hydrogen which can be made to react with oxygen with
very little additional energy. Flammable gases are often compounds of carbon and hydrogen. These
flammable gases require only small amounts of energy to react with atmospheric oxygen.
A vapour is the proportion of a liquid - if talking about the explosion protection of flammable
liquids - which has evaporated into the surrounding air as the result of the vapour pressure above the
surface of the liquid, around a jet of that liquid or around droplets of the liquid. Mist is a special type,
which because of its explosion behaviour, can be included with the vapours, for the purposes of
fulfilment of safety considerations.
Carbon
Petrol
Flammable liquids
Ether
Nitrogen
Oxygen
For this reason the flash point, or rather the flash point temperature, is an important factor when
dealing with flammable liquids. The flash point relates to the lowest temperature at which a flammable
liquid will, under certain test conditions, form a sufficient quantity of vapour on its surface to enable
an effective ignition source to ignite the vapour air mixture.
Acetone
Flammable liquids are often hydrocarbon compounds such as ether, acetone or petroleum spirit. Even
at room temperature, sufficient quantities of these can change into the vapour phase so that a potentially
explosive atmosphere forms near their surface. Other liquids form such an atmosphere near their
surface only at increased temperatures. Under atmospheric conditions this process is strongly
influenced by the temperature of the liquid.
The flash point is important for the classification of hazardous areas. Flammable liquids with a high
flash point are less dangerous than those with a flash point at room temperature or below.
When spraying a flammable liquid, a mist can form consisting of very small droplets with a very large
overall surface area, as is well-known from spay cans or from car spraying stations. Such a mist can
explode. In this case the flash point is of lesser importance. For a fine mist - made from a flammable
liquid - the behaviour relevant to safety can be roughly derived from the known behaviour of the
vapour.
Flammable solids
Flammable solids in the form of dust, fibres or flock can react with atmospheric oxygen and produce
disastrous explosions. Normally more energy is required for activating the explosion in air than with
gases and vapours. However, once combustion starts, the energy released by the reaction produces
high temperatures and pressures. In addition to the chemical properties of the solid itself, the fineness
of the particles and the overall surface area, which increases with increasing fineness, play an important
part. The properties are processes which take place immediately at the surface of the solid. Lighting
and extinguishing a paraffin wax candle provides a demonstration of a series of processes undergone
by a solid material within a short period of time which cannot easily be presented in a simplified form.
An experiment shows that when the wick of a candle is lit, the paraffin wax melts and then vaporises
and that this vapour feeds the flame. After extinguishing the candle, the paraffin vapour can still be
smelled, the melted paraffin wax solidifies and the paraffin vapours disperse. Now the paraffin wax
candle is once again a harmless object.
Flour dust
Dust reacts very differently, depending on whether it is in a deposited layer or whether it is in a suspended
dust cloud. Dust layers are liable to begin smouldering on hot surfaces, while a dust cloud which has
been ignited locally or through contact with a hot surface can explode immediately. Dust explosions
are often the consequence of smouldering dust layers which become stirred up and already carry the
ignition initiation. When such a layer is stirred up, for example by mechanical cleaning methods during
transportation or inappropriate extinguishing attempts, this can lead to a dust explosion.
A gas or vapour/air explosion can also stir up the dust, which then often leads to the first, the gas
explosion, turning into the second, the dust explosion. In deep coal mines methane/firedamp explosions
often have triggered off coal dust explosions whose consequences were more serious than those of the
original firedamp explosion.
Wood-Dust
Sugar dust
Oxygen
Oxygen
Oxygen
O2
O2
The quantity of oxygen available in the air can only oxidise/burn a certain quantity of the flammable
material. The ratio can be determined theoretically, it is called the stoichiometric mixture. When the
quantity of the flammable substance and the available atmospheric oxygen are near to at the correct
ratio, the effect of the explosion - temperature and pressure increase - is most violent. If the quantity of
flammable material is too small, combustion will only spread with difficulty or will cease altogether.
The situation is similar when the quantity of flammable material is too great for the amount of oxygen
available in the air.
All flammable materials have their explosive range, which also depend on the available activation
energy. This is usually determined by igniting the mixture with an electric spark. The explosion range
is bounded by the lower explosion limit and the upper explosion limit. This means that below and
above these limits, explosions will not happen. This fact can be utilised by sufficiently diluting the
flammable substances with air or by preventing the ingress of air/oxygen into parts of the equipment.
The latter option is, however, not, or only with restrictions, possible in environments where people
regularly work and must therefore be reserved for technological equipment.
Sources of ignition
With technical equipment a large number of ignition sources is possible. In the following overview the
numbers given behind the ignition sources refer to the appropriate sections of the basic standard:
EN 1127-1;1997 "Explosive atmospheres - Explosion prevention and protection- Part 1:
Basic concepts and methodology."
Hot surfaces (6.4.2) arise as the result of energy losses from systems, devices and components
during normal operation. In the case of heaters they are desired. These temperatures can usually be
controlled.
In the event of a malfunction - for example with overloading or tight bearings - the energy loss, and
therefore the temperature, increases unavoidably. Technical equipment must always be assessed as to
whether it is stabilising - i.e. whether it can attain a final temperature, or whether non-permissible
temperature increases are possible which need to be prevented by taking appropriate measures.
Examples: coils, resistors or lamps, hot equipment surfaces,
brakes or overheating bearings
For example, grinding and cutting devices mechanically generated sparks (6.4.4) during
normal operation are therefore not permitted in explosion hazard zones. Cracks in rotating parts, parts
sliding over each other without sufficient lubrication and similar situations can generate such sparks
when malfunctioning, and this must be carefully thought about when considering malfunctions.
Special requirements on the housing materials are intended to reduce the risks from such ignition
sources.
Examples: tools such as a rusty hammer and chisel in contact with
light alloys or the metal fork of a fork lift truck
Visible electric sparks - lightning (6.4.8) must normally be regarded as a sufficient ignition
source. Only very low energy sparks with energies of only microwatt seconds may be regarded as too
weak to start an explosion. For this reason, suitable measures must be adopted to prevent these
ignition sources.
Examples: switching sparks, sparks at collectors or slip rings
Independently of whether or not there is an electrical voltage supply, electrical sparks can be
caused by static electricity - (6.4.7). The stored energy can be released in the form of sparks and
function as an ignition source. Because this ignition source can arise quite independently of an electrical
voltage supply, it must also be considered with non-electrical devices and components. It is connected
with separation processes; therefore these cases must be assessed where this ignition source needs
to be taken into account.
Friction during normal operation can be the cause of electrostatic charging. For example, portable
devices cannot - due to their portability - be earthed or connected to an equipotential bonding ring.
When interacting with the clothes of the user, static charging can occur during normal operation.
Static electricity must be prevented from becoming an ignition source by taking appropriate measures.
Examples: Transmission belts made from plastic materials, housings of portable devices,
synthetic clothing material. Separation processes when rolling out paper or plastic
film, plastic pipe systems
Electric rails and other earthed voltage supplies e.g. for electric corrosion protection of equipment,
can result in stray electric currents, cathodic corrosion protection (6.4.6) which then may
result in a potential difference between different earthing points. This is why a highly conductive
connection to all the electrically conductive parts of the equipment must be provided so that the
potential difference is reduced to a safe level. It is not relevant whether the conductive equipment is
electrical or non-electrical parts of the installation, as the cause of the current may be found outside of
the equipment.
An equipotential bonding must always be provided, irrespective of whether or not such currents are
expected or whether its sources are known.
Flames, hot gases and particles (6.4.3) can occur inside combustion engines or analysis
devices during normal operation and when a fault has occurred. Protective measures are required
here which are able to permanently prevent them from leaving the housing.
Examples: Exhausts from internal combustion engines or
particles which are formed by the switching sparks
of power switches eroding material from the switch contacts
Among the ignition sources where radiation energy enters the potentially explosive mixture, the
following deserve to be mentioned:
Ultrasonic (6.4.12),
Electro-magnetic radiation - radio waves (6.4.9),
Electro-magnetic radiation - IR radiation, visible light (6.4.10),
ionising radiation - UV radiation (6.4.11).
If their parameters are permanently and securely limited and tested, systems, devices and parameters
utilising radiation can be operated in explosion hazard zones, otherwise the radiation must be reliably
prevented from entering the explosion hazard area.
Examples: transmitting and receiving equipment, mobile telephones, photoelectric barriers and
scanners
Finally, adiabatic compression and shock waves (6.4.13) as they occur inside
tube-shaped structures operated at an underpressure can become an ignition source.
Examples: breakage of a long fluorescent tube which is filled with a hydrogen/air atmosphere
Prevention of ignition sources
Idea
Designed to design regulations

EN 50014 to EN 50020
IEC/EN 60079-0 inc. amendments
IEC/EN 61241-00 inc. amendments
Approval by an accredited organisation

EC prototype certification
Quality assurance system in operation in

conformity with directive 94/9/EC
Manufacturer Routine tests
Installation in conformity with the

regulations regarding manufacture
IEC/EN 60079-14
IEC/EN 61241-14
Commissioning
Maintenance
10
Commissioning e. g. by an accredited expert

(1999/92/EC)
Maintenance and inspection by safety engineering

personnel (1999/92/EC)
IEC/EN 60079-17
IEC/EN 61241-17
Protection principles are defined as principles which exclude systems, devices and components as
ignition sources.
Ignition sources which are caused by sparks from friction or impact or from electro-static charging
have to be prevented in explosion-protected equipment by selecting an appropriate material and by
constructive measures, and this must be verified and confirmed by the appropriate tests.
Four protection principles can prevent equipment from becoming an ignition source. The types of
protection listed as examples in the overview are discussed in a different section.
An important precondition for all the protection principles is that parts which are in unhindered contact
with the potentially explosive atmosphere must not be able to reach non-permitted temperatures, which
depend on the ignition temperature. This means that the ignition temperature is relevant for all protection
principles.
The protection principles can be equally applied to electrical and non-electrical devices and for gases
and for dust. The principles allow for a design in various safety categories in accordance with the Ex
directive 94/9EC.
Category 1 - with maximum scope of protection and thus a very high degree of safety
Category 2 - with increased scope of protection and therefore a high degree of safety
Category 3 - with conventional scope of protection and therefore a conventional degree of safety
Overview
Flammable substances
Types of protection
Category
1. Potentially explosive mixtures can penetrate

the item of electrical equipment and be ignited.
Measures are taken to ensure that the explosion
cannot spread to the surrounding atmosphere.
Gases
Flammeproof enclosure
Powder filling
Enclosed break device
2. The item of equipment is provided with an

enclosure that prevents the ingress of a potentially
explosive mixture and/or contact with sources of
ignition arising from the normal.
Gases and dust
Gases
Dust
Encapsulation
Oil immersion
Non-incendive component
Hermetically sealed device
Sealed device
Encapsulated device
n-pressurizatio
Protection by enclosure
3. Potentially explosive mixtures can penetrate the

enclosure but can not be ignited. Sparks and
temperatures capable of causing ignition must be
prevented..
Gases
4. Potentially explosive mixtures can penetrate the

enclosure but can not be ignited. Sparks and
temperatures able to cause ignition may only
occur within certain limits.
Gases and dust
Energy limited circuit
Gases
Intrinsic safety
Protection by control of
ignition sources
Increased safety
Non-sparking device
Protection by constructional safety
BARTEC applies these protection principles to its different pieces of equipment according to the
application for which they are going to be used. The industrial products of other manufacturers are
also equipped by BARTEC for use in explosion hazard zones.
11
Non-technical measures
The requisite preconditions for the safe operation of electrical equipment in hazardous areas are created
in a joint effort by the manufacturers of explosion-proof electrical equipment and the constructors and
operators of industrial plants. It is important that the operator of such plants should ensure that their
personnel know how the danger of explosions is likely to arise and the measures that are to be taken to
prevent it.
The employees should be regularly trained on the contents of the explosion protection document in
accordance with the directive 1999/92/EC - in the Federal Republic of Germany implemented on the
basis of the "BtrSichV Betriebssicherheitsverordnung" (occupational safety regulations) - and informed
by means of written corporate directives which should be regularly updated. BARTEC as a specialist
for safety technology offers such consultation and training.
Design regulations for explosion protected systems,

devices and components - equipment
Hazards arising from the handling of flammable gases, vapours and dust are caused by uniform chemical
and physical processes. For this reason, the protection against these hazards must be carried out in a
uniform manner.
Nearly universal uniform requirements have now been formulated by the International Electrotechnical
Commission IEC, by the European Standardisation Committees CENELEC and CEN and by DKE and
DIN.
Manufacturers and operators are required to adhere to these, and where there is an increased protection
requirement, they are monitored by accredited test houses and the authorities.
12
Regulations
An overview of the regulations for the determination of the parameters, the classification of the zone,
the design regulations for systems, devices and components as well as installation and operation in
the area where potentially explosive gases, vapours and dust is present, is shown in the table below
which corresponds to the version as of April 2004 and may be subject to subsequent changes.
Title/Content
Document ident.
IEC
Publication date
Document ident.
CEN/CENELEC
Publication date
Document ident.
DIN
Publication date
Explosive atmospheres - Explosion prevention and protection

Part 1:
Basic concepts and methodology
EN 1127-1
1997-08-00
DIN EN 1127-1
1997-10-00
Explosive atmospheres - Explosion prevention and protection

Part 2:
Basic concepts and methodology for mining
EN 1127-2
2002-04-00
DIN EN 1127-2
2002-07-00
Potentially explosive atmospheres - Explosion prevention and protection

Part 1:
Terms and definitions for equipment and protective systems
intended for use in potentially explosive atmospheres
EN 13237
2003-06-00
DIN EN 13237
2003-11-00
Determination of the maximum explosion pressure and maximum rate

of pressure rise of gases and vapours Part 1: Determination of the maximum explosion pressure
EN 13673-1
2003-00-00
DIN EN 13673-1
2003-09-00
Determination of the maximum explosion pressure and maximum rate

und des maximalen zeitlichen Druckanstieges fr Gas und Dmpfe
Part 2:
Determination of the maximum explosion pressure
prEN 13673-2
2002-07-00
DIN EN 13673-2
2002-08-00
Electrical apparatus for explosive gas atmosphere

Part 1-1: Flameproof enclosures "d"; Method of test for ascertainment
for maximum experimental safe gap
IEC 60079-1-1
2002-07-00

Part 12: Classification of mixtures of gases or vapours with air according to
their maximum experimental safe gaps and minimum igniting currents
IEC/TR 60079-12
1978-00-00
Electrical apparatus for explosive gas atmospheres

Part 20: Data for flammable gases and vapours,
relating to the use of electrical apparatus
IEC/TR3 60079-20
1996-10-00

Part 4:
Method of test for ignition temperature
IEC 60079-4
1975-00-00

Part 4:
Method of test for ignition temperature; Amendment 1
IEC 60079-4 AMD1

1995-06-00
Testing of mineral oil hydrocarbons

Determination of ignition temperature
DIN 51794
2003-05-00
Electrical apparatus for use in the presence of combustible dust

Part 2:
Test methods - Section 1: Methods for determining
the minimum ignition temperatures of dust
IEC 61241-2-1
1994-12-00

Part 2-1: Test methods; Methods for determining
the minimum ignition temperatures of dust
EN 50281-2-1
1998-00-00
DIN EN 50281-2-1
1999-11-00
Electrical apparatus for use in the presence of combustible dust;

Part 2:
Test methods - Section 2: method for determining the
electrical resistivity of dust in layers
IEC/TR 61241-2-2
1993-08-00
EN 61241-2-2
1995-08-00
DIN EN 61241-2-2
1996-04-00

Part 2:
Test methods - Section 3: Method for determining
minimum ignition energy of dust/air mixtures
IEC 61241-2-3
1994-09-00
Electrical apparatus for use in presence of combustible dust

Part 2:
Test methods - Section 4: Method for determining
the low explosive limit of dust/air mixtures
prEN 61241-2-4
1993-05-00
Basics
Characteristics of combustible gases and vapours
Characteristics of combustible dusts
13
Title/Content
Document ident.
IEC
Publication date
Document ident.
CEN/CENELEC
Publication date
Document ident.
DIN
Publication date
IEC 60079-10
2002-06-00
EN 60079-10
(2003-04)
IEC 61241-10
(2002-04-00)
prEN 61241-10
(2002-04)
DIN EN 61241-10
(2002-11)
Classification of hazardous areas with combustible gases and vapours

Electrical apparatus for exlosive gas atmosphere
Part 10: Classification of hazardous areas
Classification of hazardous areas with combustible dusts
Part 3: Classification of areas where combustible dusts are or
may be present
Types of protection for explosion-proof electrical apparatus
- electrical apparatus -
combustible gases and vapours

Part 0: General requirements
IEC 60079-0
2004-01-00
prEN 60079-0
2003-10-00
DIN EN 60079-0
2003-02-00

Part 1: Flameproof enclosure "d"
IEC 60079-1
2003-11-00
prEN 60079-1; 2002

2003-07-00
DIN EN 60079-1
2002-07-00

Part 2: Pressurised enclosure "p"
IEC 60079-2
2001-02-00
prEN 60079-2
2003-02-00
DIN EN 60079-2
2003-07-00

Part 5: Powder filling "q"
IEC 60079-5
2003-09-00
Electrical apparatus for explosive atmospheres

Part 6: Oil immersion "o"
IEC 60079-6
1995-05-00

Part 7: Increased safety "e"
IEC 60079-7
2001-11-00
EN 60079-7; 2002
2003-08-00
DIN EN 60079-7
2004-02-00

Part 11: Intrinsic safety "i"
IEC 60079-11
1999-02-00
EN 50020
2002-06-00
DIN EN 50020
2003-08-00
Explosion-proof electro-technical apparatus

Part 13: Construction and use of rooms or buildings
protected by pressurization (report)
IEC/TR 60079-13*
1982-00-00

Part 15: Type of protection "n"
IEC 60079-15
2001-02-00
prEN 60079-15
2002-10-00
DIN EN 60079-15
2003-05-00

Part 16: Artificial ventilation for the protection of analyser(s) houses
IEC/TR 60079-16*
1990-04-00

Part 18: Encapsulation "m"
IEC 60079-18
1992-10-00
prEN 60079-18
2003-11-00
DIN IEC 60079-18

2002-09-00

Part 19: Repair and overhaul of apparatus used in
explosive atmospheres (other than mines or explosives)
IEC 60079-19
1993-09-00
prEN 60079-19
1992-09-00

Part 25: Intrinsically safe systems
IEC 60079-25
2003-08-00
EN 60079-25
2004-01-00
DIN EN 50039
2001-09-00

Part 26: Special requirements for the construction, test and
marking for electrical apparatus for use in Zone 0
IEC 60079-26
DIN IEC 60079-26

2002-02-00

Part 27: Fieldbus intrinsically safe concept (FISCO) and
fieldbus non-incendive concept (FNICO)
DIN IEC 60079-27

2004-03-00
* Changes to the registration number can arise due to the comparison between IEC or ISO and CENELEC or CEN.
14
Title/Content
Document ident.
IEC
Publication date
Document ident.
CEN/CENELEC
Publication date
Document ident.
DIN
Publication date

Part 0: General requirements
IEC 61241-0
2002-04-00
prEN 61241-0
2002-04-00
DIN EN 61241-0
2002-10-00

Part 1: Protection by enclosures "tD"
IEC 61241-1
2004-01-00
prEN 61241-1
2004-01-00
DIN EN 61241-1
2002-10-00

Part 4: Type of protection "p"
IEC 61241-4
2001-03-00

Part 11: Protection by intrincis safety "iD"
IEC 61241-11
2004-02-00
prEN 61241-11
2004-02-00

Part 18: Protection by encapsulage "mD"
IEC 61241-18
2002-09-00
prEN 61241-18
2002-09-00
combustible dust
Type of Protection (explosion protection)
- Non-electrical equipment -
combustible gases, vapours as well as dusts

Non-electrical equipment for potentially explosive atmospheres
Part 1: Basic methodology and requirements
EN 13463-1
2001-11-00
DIN EN 13463-1
2002-04-00

Part 2: Protection by flow restricting enclosure "fr"
prEN 13463-2
2002-11-00
DIN EN 13463-2
2003-01-00

Part 3: Protection by flameproof enclosure "d"
prEN 13463-3
2002-08-00
DIN EN 13463-3
2002-10-00

Part 4: Protection by inherent safety

Part 5: Protection by constructional safety "c"
EN 13463-5
2003-12-00
DIN EN 13463-5
2004-03-00

Part 6: Protection by control by ignitin sources "b"
prEN 13463-6
2002-08-00
DIN EN 13463-6
2002-11-00

Part 7: Protection by ...

Part 8: Protection by liquid immersion "k"
prEN 13463-8
2003-09-00
DIN EN 13463-8
2004-01-00
15
Title/Content
Document ident.
IEC
Publication date
Document ident.
CEN/CENELEC
Publication date
Document ident.
DIN
Publication date

Part 14: Electrical installations in hazardous areas (other than mines)
IEC 60079-14
2002-10-00
EN 60079-14
2003-08-00
DIN EN 60079-14

Part 14: Selection and installation
IEC 61241-14
prEN 61241-14; 2002
DIN EN 61241-14
2002-10-00

Part 17: Inspection and maintenance of electrical installations in
hazardous areas (other than mines)
IEC 60079-17
2002-07-00
prEN 60079-17; 2002
DIN EN 60079-17
2002-10-00

Part 19: Repair and overhaul for apparatus used in explosive
atmospheres (other than mines or explosives)
IEC 60079-19
1993-09-00
Explosion protection in plants: Installation, maintenance and repair
Note about how to use the table

The information is based on the IEC titles, in cases where there is no IEC document available, the EN titles have been used.
The format of the date has been standardised. It refers to the state on 2004-04-30 which was accessible to the author. This style seems to be becoming universally
accepted, but has not been introduced in all the documents.
The table is to provide an information overview of the standard. For concrete work with the standards and their procurement, the latest update should be requested from
the publisher or from the standardisation committee. According to our experience, it must be expected that in the years up to 2005, a number of the standards will be
modified.
With the help of this table, the following contents listed in the title/contents column can be correlated
to the regional and national equivalents. The regional and national title does not need to correspond
to the "world" title. (Please also note the footnote for the table!)
At BARTEC the design regulations are consistently applied for electrical equipment. Conformity
is - after the completion of the development at BARTEC - checked by EC notified bodies, notified
bodies of the IEC Ex scheme as well as notified bodies of the European Community or by national test
houses, and compliance is monitored and realised using a quality assurance system for every piece of
equipment produced. During the routine test, safety-relevant requirements are checked according to
the specifications and confirmed by means of a marking.
BARTEC also supports its customers with non-electrical equipment using the knowledge it has
accumulated over decades of experience.
16
Relevance and advantage of the classification in zones

The practice has been established of dividing hazardous areas into zones. This classification takes the
different dangers from potentially dangerous atmospheres into account and allows explosion protection
measures to be taken which reflect the situation both from the point of view of safety engineering and
of economics. For the European community, the zone definitions are uniformly provided in directive
1999/92/EC. It must be applied with technical unterstanding of the concrete situation.
IEC 60079-10 assumes an approximately similar classification for gases and vapours which will also
apply to future facilities constructed conforming to the USA standard NEC 505. IEC 61241-10 provides
support for the zone classification with dust.
Explosion hazard zones are classified depending on the frequency and duration of the potentially
explosive atmosphere.
This classification provides the scope of the measures to be taken according to annex II section A in
the directive 1999/92/EC in conjunction with annex I of the directive 94/9/EC.
Classification of hazardous places

Zone 0
A place in which an explosive atmosphere consisting of a mixture with air of flammable substances in
the form of gas, vapour or mist is present continuously or for long periods or frequently.
Zone 1
the form of gas, vapour or mist is likely to occur in normal operation occasionally.
Zone 2
the form of gas, vapour or mist is not likely to occur in normal operation but, if it does occur, will
persist for a short period only.
Zone 20
A place in which an explosive atmosphere in the form of a cloud of combustible dust in air is present
continuously, or for long periods or frequently.
Zone 21
A place in which an explosive atmosphere in the form of a cloud of combustible dust in air is likely
to occur in normal operation occasinoally.
Zone 22
A place in which an explosive atmosphere in the form of a cloud of combustible dust in air is not
likely to occur in normal operation but, if it does occur, will persist for a short period only.
Notes:
1. Layers, deposits and heaps of combustible must be considered as any other source which can form an explosive
atmosphere.
2. 'Normal operation' means the situation when installations are used within their design parameters.
3. The definitions comply with the EC directive. In the HSE occupational safety regulations, hazardous explosive
atmospheres are defined.
In according with EN 1127-1
Section 3.17 defines potentially explosive atmospheres as follows: Mixture of air and flammable gases, vapours,
fogs and dusts under atmospheric conditions due to a transmission of the burning process to the entire unburned
mixture after inflammation.
Section 3.19 defines hazardous potentially explosive atmospheres as follows: Potentially explosive atmosphere
which will lead to damage in case of explosion.
17
In places of work the explosion hazard areas are normally classified at most as zone 1 and 2 and/or 21
and 22. Zones 0 and 20 are restricted to very small inaccessible areas in workplaces or are usually
estricted to the inside of technical equipment.
Zone 0
Zone 1
Zone 2
Zone 20
Zone 21
Zone 22
Explosion engineering parameters

In order to allow a combination of measures for explosion protection, which is optimised with respect
to the chemical-physical properties of the flammable gases, vapours or dust to be made, and therefore
a standardisation of the types of protection to be possible for the manufacturer, a system of explosion
engineering parameters has been created. These are determined using an application orientated testing
method.
Before flammable substances can react with the atmospheric oxygen in an explosion, energy must be
provided.
This energy may, for example, be exchanged on a surface. A heated surface increases the energy
content of the potentially explosive mixture in contact with it. If the surface temperature is sufficiently
high, this increased energy content can lead to the explosive reaction. However, the energy may also
be supplied through a spark or a hot gas jet flowing out of a gap into the potentially explosive mixture.
Both types lead to different explosion engineering parameters being defined.
18
Ignition temperature - temperature class

Many factors such as size, shape, type and surface quality have an influence on the ignition temperature.
IEC, CENELEC and other standardisation committees have agreed on a method for gases and vapours
defined in IEC 60079-4 "Method of test ignition temperature". This method is defined in such a way,
that a value very close to the lowest practically possible, is determined.
By means of this method, gases and vapours are divided into temperature classes. According to these
temperature classes, the surface temperatures in explosion-protected equipment and other technological
objects is designed in such a way that ignition by the surface is not possible. In the standard, permissible
excess values and necessary safety margins below these standard values are defined in detail.
Temperature
classes
Ignition temperature
range of the mixture
Permissible surface temperature

of the electrical equipment
T1
> 450 C
450 C
T2
> 300 ... < 450 C
300 C
T3
> 200 ... < 300 C
200 C
T4
> 135 ... < 200 C
135 C
T5
> 100 ... < 135 C
100 C
T6
> 85 ... < 100 C
85 C
For different types of dust, the method for determining the ignition temperature has also been unified
and coded in document IEC 61241-2-1. Please note that dust in its deposited form - determined using
procedure A - has a different ignition temperature than in its stirred form - determined as a cloud
using procedure B.
The permissible surface temperature for those parts of the systems, devices and components accessible
to the dust is determined by subtracting 75 K from the value determined using procedure A and by
multiplying by 2/3 the value determined using procedure B. The smaller of the 2 values determined in
this way corresponds to the lowest permissible surface temperature of the equipment. The surface is
the area accessible to the dust, temperature classes are not defined for dust, so that a concrete type of
dust must always be assumed. The parameters are made available in comprehensive tables, laboratories
determine the values on request, and a small, non-official overview is contained in the following
table.
19
Examples of the ignition temperatures of different types of dust
Designation
of the solid
material
A values
ignition temperature
IEC 50381-2-1
procedure A
deposit (C)
B values
ignition temperature
IEC 50381-2-1
procedure B
450...
cloud (C)
> 300
Permissible limiting temperature

lowest value of the calculation (A-75K) und 2/3*B
300...
> 280
280...
> 260
260...
> 230
230...
> 215
215...
> 200
200...
> 180
180...
> 165
165...
> 160
160...
> 135
Dust from natural materials (examples)

Cotton
Brown coal
Cellulose
Cereals
Wood resin
Sawdust (wood)
Cocoa
Copra
Cork
Fodder concentrate
Linen
Milk powder
Paper
Pectin sugar
Soya
Starch
Hard coal
Tabacco
Tapioca
Tea
Peat
Wheat flour
Sugar beet
350
225
370
290
290
300
460
290
300
295
230
340
300
380
245
290
245
300
290
300
295
450
290
560
380
500
420
500
400
580
470
470
525
440
440
540
410
500
440
590
450
450
510
360
480
460
275
150
295
215
215
225
385
215
225
220
155
265
225
273
170
215
170
225
215
225
220
320
215
Dust of chemical technical products (examples)

Cellulose ether
Isosorbide dinitrate
Unvulcanised rubber
Petroleum coke
Polysaccharide deriv.
Polyvinyl acetate
Polyvinyl chloride
Soot
Laminated plastic
Sulphur
275
330
240
220
280
270
340
380
385
330
280
220
460
690
580
500
530
620
510
280
280
260
300
305
410
285
440
530
390
310
690
610
330
570
200
146
145
205
195
265
305
310
255
186
Metal dust (examples)

Aluminium
Bronze
Iron
Copper silicon alloy
Magnesium
Manganese
Zinc
20
205
185
206
230
335
210
365
Minimum ignition current ratio - Maximum experimental

safe gap Explosions Sub-group
Ignition on a hot surface occurs in a relatively large macroscopic part of the mixture. In contrast,
the ignition from a spark spreads in a relatively small microscopic part of the volume. The discharge
from a capacitor or the interruption of a predefined resistive/inductive electric circuit can be used for
classifying gases and vapours or dust according to their ease of ignition in the microscopic part of the
mixture volume.
For the assessment of the ignition of the gases and vapours in a circuit using a device defined in
IEC 60079-11, a comparative value with methane as reference in a standardised circuit is used. This
comparative value is the minimum ignition ratio, MIC. It is the means used for classifying gases and
vapours within explosion group II in the subgroups IIA, IIB and IIC.
An analogue value is found when the ease of ignition by a hot gas jet flowing through a gap is used for
the classification. In IEC 60079-1A Determination of the experimental safe gap a test apparatus is
specified in which a spherical gas volume of 20 cm is enclosed by two hemispheres. They are
equipped with a 25 mm wide flange. This ball-shaped object is placed into a larger vessel and both
spaces are filled with the mixture for which the safe gap is to be determined. The gap between the
25 mm wide flanges for which ten ignitions inside the ball volume just fail to ignite the mixture in the
outer vessel is a value specific to the mixture and is called the maximum experimental safe gap,
MESG.
The processes involved in the prevention or spread of the explosion in the gap are very complex.
Classifying the gases and vapours by the safe gap results approximately - with a small overlap - in the
same classification as that obtained with the minimum ignition current. IEC/TR 60079-12 provides an
overview of the classification using the two measuring methods MESG and MIC.
The safe gap value is of considerable importance for designs of ignition protection type Flameproof
enclosure. The value for the minimum ignition current is important for those of ignition protection
type Intrinsic safety. For these two types of protection, the subgroups IIA, IIB and IIC for gases and
vapours are relevant. The information about gases and vapours can also be applied approximately to
mists.
For the assessment of conditions concerning electrostatic discharge, the minimum ignition energy
of gases and vapours from the assignment to sub-group IIA, IIB or IIC can be assumed:
IIA approx. 300 Ws
IIB approx. 50 Ws
IIC <
50 Ws
For dust, standards for the determination of parameters are already available or are in preparation.
The minimum ignition energy, a parameter similar to the minimum ignition current, is determined in
accordance with IEC 61241-2-3 for flammable dusts.
21
Examples of the classification of gases and vapours into temperature classes

and explosion hazard subgroups are listed in the following table:
Explosion groups Classification according to MESG

Temperature class
T1
> 450 C
IIA
IIB
IIC
> 0.9 mm
0.9... 0.5 mm
< 0.5 mm
Acetone
Town gas
Hydrogen
Ethyl alcohol,
Ethylene
Ethine (acetylene)
i amyl acetate
Ethylene oxide
Ammonia
Benzene - pure
Acetic acid
Ethane
Ethyl acetate
Ethyl chloride
Carbon monoxide
Methane
Methanol
Methylene chloride
Naphthalene
Phenol
Propane
Toluene
T2 > 300 ... 450 C
n butane
n butyl alcohol
Cyclohexane
Acetic anhydride
T3 > 200 ... 300 C
Petroleum spirit - gen.
Ethylene glycol
Diesel fuel
Hydrogen sulphide
Jet propulsion fuel

Heating fuel DIN 51603
n hexane
T4 > 135 ... 200 C
Acetaldehyde
Ethyl ether
T5 > 100 ... 135 C

T6 > 85 ... 100 C
22
Carbon bisulphide
Types of protection
Types of protection
It applies to all types of protection where parts that are in unhindered contact with the potentially
explosive atmosphere are not permitted to reach unacceptably high temperatures.
Taking into account both the environmental temperature and the heating effect, the temperature may
attain maximum values which corresponds to the temperature class or the permissible temperature
specified for flammable dusts in accordance with which the potentially explosive atmosphere has been
classified.
General requirements
Principle
All generally applicable requirement s for the operating equipment are summarised in the standards
IEC 60079-0 for gases and vapours
IEC 61241-0 for dusts and
EN 13463-1 for non-electrical devices.
Uniform protection requirements concerning several types of protection such as protection against
electrostatic charging, provision of a potential bond for metal housings, or mechanical strength against
impact, are summarised in these standards under general engineering requirements. In this case,
individual, more specific standards can demand either more stringent requirements or less stringent
ones.
These requirements are based partially on those for electrical equipment for gases and vapours,
deviations for dust and non-electric equipment are contained in the individual basic standards.
Categories 1 to 3 which the equipment has to fulfil can also include different general requirements.
The general temperature range for the application of explosion-protected equipment is defined
as -20 C to +40 C. Permissible deviations extending or restricting the temperature range must be
specified.
The parameters determined at approximately +20 C in the laboratory for the subgroups IIA, IIB and
IIC apply for a temperature range of 40 K - that is to say also from -20 C to +60 C.
These two temperature ranges take, on the one hand, the situation at the workplace into account and
also, on the other, a certain heating up of the equipment when operating. The explosion pressure,
permissible gap widths and permissible non-igniting currents change outside this temperature range.
This has to be considered when using the equipment, and it can require different test conditions.
Information about the use of the markings

The markings used below for non-electrical equipment and dust explosion protection are still under discussion.
For this reason they have to be treated as provisional.
23
Types of protection
Ignition protection type
Gases/Vapours
Gases/Vapours
Dust
electrical
equipment
non-electrical
equipment
electrical
equipment
n-pressurizatio
Powder filling
Increased safety
Non sparking apparatus
Oil immersion
Encapsulation
Encapsulated device
Sealed device
Protection by enclosure
Intrinsic safety
Protection by constructional safety
Marking "Ex d" II 2 G
Marking "d"
II 2 G
in accordance with IEC 60079-0

in accordance with EN 13463-1
Principle
A type of ignition protection in which the parts which could ignite a potentially explosive atmosphere
are located inside an enclosure which can withstand the pressure of an explosion of the potentially
explosive mixture inside, and prevents the transmission of the explosion to the potentially explosive
atmosphere surrounding the enclosure.
Technically unavoidable gaps are so long and narrow that hot gases jetting out will have lost their
power to cause ignition by the time they reach the outside of the housing, or, alternatively, if the gaps
are only required for the manufacturing process they might be sealed with adhesive.
Important design parameters

Mechanical strength in accordance with a defined safety factor to withstand internal explosion
pressure.
As an orientation value, it may be assumed that inside the sphere approx. 0.8 MPa (8 bar) can be
generated and that this sphere used as an EEx d enclosure must be able to withstand a pressure of
1.2 MPa (12 bar).
Any gap between two parts of the enclosure must be kept so narrow and long that hot gas flowing
out will not be able to ignite any potentially explosive atmosphere which may be present in the
explosion hazard zone.
The parameters for the gaps preventing the transmission of the ignition, width/length, are different
for the explosion hazard subgroups IIA, IIB and IIC. The most stringent requirements with regard
to the gap parameters apply to enclosures in explosion hazard subgroup IIC.
Applications
Equipment where, during normal operation, sparks, electric arcs and/or hot surfaces are generated
such as switchgear, slip rings, collectors, adjustable resistors, fuses or lamps, heating cartridges,
friction brakes.
24
Types of protection
Marking "Ex tD"
II 2 D
Principle
The housing is sealed so tight, that no combustible dust can enter. The surface temperature of the
external housing is limited.

Minimum degree of protection in accordance with IEC/EN 60529 IP 6X.
Consideration of dust accumulating on the surface and reduction of permissible surface temperature
with dust layer 5 mm are possible.
Applications
Various equipment where during normal operation sparks, electric arcs or hot surfaces occur and
complex industrial designs (controllers) which by means of this type of ignition protection can be
utilised in explosion hazard zones.

Marking "Ex nC"
II 3 G
Principle
switchgear as a variant of the Ex n type of ignition protection, with contacts which close and open a
circuit potentially able to trigger an explosion, where the enclosure will withstand an internal explosion
of a mixture of subgroup IIA, IIB or IIC without being damaged and without transferring the explosion
to the external mixture in the surrounding area.

Free internal volume 20 cm.
The encapsulation must permit a permanent temperature of the 10 K
compared to the maximum operating temperature
Limited to AC 690 V and 16 A.
Applications
Contact systems
Marking "Ex nC"
II 3 G
Principle
Variant of the Ex n type of ignition protection with contacts which close and open a circuit potentially
able to trigger an explosion, where the contact mechanism or the enclosure into which the contacts
are enclosed is designed in such a way that the ignition of a mixture of subgroup IIA, IIB or IIC in the
surrounding environment is prevented as long as defined operating conditions apply.

Free internal volume 20 cm.
The encapsulation must permit a permanent temperature of 10 K
compared to the maximum operating temperature.
The combination of the parts is tightly sealed or
The design of the contacts will extinguish any incipient flame.
Limited to AC 254 V and 16 A.
L and C are part of the test.
Explosion hazard subgroups IIA, IIB and IIC are to be treated differently.
Applications
Contact systems
25
Types of protection
Marking "Ex p"
Marking "Ex pD"
Marking "p"
II 2 G
II 2 D
II 2 G/D

Principle
The ingress of the surrounding atmosphere into the housing of electrical equipment is prevented by
maintaining an ignition shield gas (air, inert or a different suitable gas) inside it at a pressure above
atmospheric pressure. The overpressure is maintained with or without constant flushing of the protective
gas.

Housing strength; the enclosing, flushed housing must withstand 1.5 times the overpressure
experienced during normal operation.
Flush before commissioning the electrical equipment.
Shut-down or alarm if the flushing gas flow or overpressure fails.
Applications
Equipment where during normal operation sparks, electric arcs or hot surfaces are generated and
complex industrial equipment (controls) which must be operated in explosion hazard zones protected
by this type of ignition protection.
Large machines, slip ring or collector motors, switch cabinets and control cabinets and analytical
apparatus.
n-pressurization
Marking "Ex pz"
II 3 G
Principle
Use of a protective gas preventing ignition inside a housing to prevent the formation of a potentially
explosive atmosphere inside the housing by maintaining a pressure greater than the that in the
surrounding atmosphere.

The important difference from the pressurised enclosure is the restriction to a housing where no
internal sources are available and no flammable gases or vapours can be released.
Housing strength.
Flush before commissioning the electrical equipment.
Shut-down or alarm if the flushing gas flow or overpressure fails.
Applications
Equipment where during normal operation sparks, electric arcs or hot surfaces are generated and
complex industrial equipment (controls) which must be operated in explosion hazard zones protected
by this type of ignition protection.
Analytical apparatus without internal sources.
26
Types of protection
Powder filling
Marking "Ex q"
II 2 G
Principle
By filling the housing with a finely grained powder, an arc within the housing is unable, with correct
use, to ignite the potentially explosive atmosphere outside. There must be no risk of ignition by flames,
nor by increased temperatures at the housing surface.

The filling such as sand, glass balls etc. has to fulfil specific requirements, as must the housing
design. The filling must not be able to leave the housing, neither during normal operation, nor as
the result of electric arcs or other processes inside the powder-filled enclosure.
Applications
Capacitors, electronic assembly groups or transformers which are used in an explosion hazard
zone. Often components where sparks or hot surfaces occur but whose functioning is not affected
by the finely grained filling.
1)
1)
2)
Oil/ 2)Liquid immersion
Marking "Ex o"

Marking "k"
II 2 G
II 2 G

Principle
Parts which might ignite a potentially explosive atmosphere are immersed in oil or other non-flammable,
insulating liquid so that gases and vapours above the oil level and outside the housing cannot be
ignited by electric arcs or sparks generated below the oil level, or by hot residual gases from the
switching process or by hot surfaces - e. g. on a resistor.

Stipulated, insulating liquids, e. g. oil
Protection of the liquid from contamination and moisture.
Assurance and possibility of monitoring that the oil level is safe
- when heated up or cooled
- for identification of leaks
Restricted to non-portable devices.
Applications
Large transformers, switchgear, starting resistors and complete starting controllers.
27
Types of protection
Increased safety
Marking "Ex e"
II 2 G
Principle
Additional measures provide a higher degree of safety. This ensures reliable prevention of unacceptably
high temperatures and sparks or electrical arcs, both on the internal and on the external parts of
electrical equipment whose normal operation does not involve unacceptably high temperature sparks
or arching.

For uninsulated, live parts, special protective requirements apply.
Air and creepage gaps are made wider than is generally the case in industry.
Special conditions apply to the IP protection degree to be adhered to.
For windings, their construction, mechanical strength and insulation, higher requirements apply
and the windings must be protected from increased temperatures.
Minimum cross sections are stipulated for winding wire, the impregnation and reinforcement of
coils and for thermal monitoring devices.
Applications
Installation material such as junction boxes, connection cabinets for heating systems, batteries,
transformers, ballasts and cage motors.
Non-sparking apparatus
Marking "Ex nA"
II 3 G
Principle
The construction ensures reliable prevention of unacceptably high temperatures and sparks or electrical
arcs, both on the internal and on the external parts of electrical equipment whose normal operation
does not involve unacceptably high temperature sparks or arcing.

For uninsulated, live parts, special protective requirements apply.
Air and creepage gaps are specified.
Special requirements must be fulfilled by certain types of equipment.
Applications
Installation material such as junction boxes, connection cabinets, rotating electrical machines,
special fuses, lamps, cells and batteries, transformers and low energy equipment
Constructive safety
Marking "c"
II 2 G/D
Principle
The systems, devices and components are constructed in a way which ensures that they cannot turn
into an ignition source under normal operation or in cases of faults.
Important constructive parameters

Requirements placed upon the enclosure material are applicable as with the other types of
protection (refer to, e. g., EN 60079-0).
The components must be selected in a way which ensures that their heating-up, e. g. by means of
friction, is excluded.
Furthermore, friction occurring under normal operation must not lead to electrostatic charging or
friction sparks.
The constructive requirements - derived from EN 1127-1 - must be verified with regard to possible
ignition sources.
Applications
Presently, only little experience is available as the standard is only applicable as draft yet.
28
Types of protection
Encapsulation
Marking "Ex m"
Marking "Ex mD"
II 2 G
II 2 D

Principle
Parts that could ignite a potentially explosive atmosphere by means of sparks or heat are potted soas
to prevent ignition of the potentially atmosphere. This is achieved by encapsulating the components
in a compound resistant to physical - especially electrical, thermal and mechanical - and chemical
influences.

Encapsulation:
- Breakdown strength
- Low water absorption
- Resistance to various influences
- Potting must be of the stipulated thickness all round
- Cavities are only permitted to a limited extent
- As a rule the potting is only penetrated by the cable entries
The load on the components is limited or reduced
Increased clearance between live parts
Applications
Static coils in ballasts, solenoid valves or motors, relays and other control gear, of limited power
and complete PCBs with electronic circuits.

Marking "Ex nC"
II 3 G
Principle
The equipment may include cavities. It is constructed in such a way that the external atmosphere
cannot enter.

Sealed by means of a melting process e. g.:
- Soft solder
- Hard solder
- Welding
- Fusing of glass and metal
Applications
Spark generating equipment
29
Types of protection
Encapsulated device
Marking "Ex nC"
II 3 G
Principle
The equipment may include cavities which are fully enclosed similar to the encapsulation type of
ignition protection e. g. in a potting compound, so that ingress of the outer atmosphere is prevented.

It must be impossible to open the equipment during normal operation,
internal free volume 100 cm
External connections, terminals or cables must be available
Cast seal must permit permanent operating temperature 10 K compared to the maximum
operating temperature
It must not be possible for elastic seals to become mechanically damaged under normal operating
conditions; they must maintain their sealing properties over the service life of the equipment
Applications
Contact systems, static coils in ballasts, solenoid valves or motors and complete PCBs with
electronic circuits.
Sealed device
Marking "Ex nC"
II 3 G
Principle
The equipment may include cavities, which are fully enclosed similar to the encapsulation type of
ignition protection so that ingress of the outer atmosphere is prevented.

It must be impossible to open the equipment during normal operation,
internal free volume 100 cm
External connections, terminals or cables must be available
conditions; they must maintain their sealing properties over the service life of the equipment
Applications
Contact systems, static coils in ballasts, solenoid valves or motors and complete PCBs with
electronic circuits.
30
Types of protection
Intrinsic safety
Marking "Ex i"
Marking "Ex iD"
II 2 G
II 2 D

Principle
Intrinsically safe electrical equipment contains only circuits that meet the requirements of
intrinsically safe circuits.
Intrinsically safe circuits are circuits in which no spark or thermal effect occurring under the test
conditions laid down in the standard can ignite the potentially explosive atmosphere of subgroups
IIA, IIB and IIC or of an air/dust mixture. The test conditions cover normal operation and certain fault
conditions stipulated in the standard.

Use of certain components for electrical and electronic circuits.
Lower permitted load on the components than in ordinary industrial applications with regard to
- voltage related to electric strength
- current related to heat
Voltage and current, including a safety margin, are kept permanently so low that no impermissible
temperatures can occur, and, in the event of open circuit or short-circuit, sparks and electric arcs
possess so little energy that they are unable to ignite a potentially explosive atmosphere.
An impression of this protection type is provided by the fact that potentially explosive atmospheres
of subgroup IIA require only a few hundred W and those of subgroup IIC only 10W for ignition.
Applications
Measuring and monitoring instrumentation and control.
Sensors working on the basis of physical, chemical or mechanical principles and at limited
power.
Actuators working on the basis of optical, acoustic and, to a certain extent, mechanical principles.
Inherent safety
Marking "g"
II 2 G/D
Principle
The processes within the device i.e. relative speed and the striking energy - are at such a low dynamic
level that an ignition of flammable mixtures is excluded. The standard is still in its initial draft state,
such devices may be omitted from the validity scope of the directive 94/9/EC due to the fact that they
bear no potential ignition source.

Marking "Ex nL"
II 3 G
Principle
These are circuits in which no spark or thermal effect occurring under the test conditions laid down in
the standard can ignite the potentially explosive atmosphere of subgroups II A, II B and II C or of an
air/dust mixture.
The test conditions cover normal operation and certain fault condition stipulated in the standard.
The permissible currents or voltages exceed those stipulated for the intrinsic safety type of ignition
protection.

The requirements to be fulfilled by the circuit and the loads on the components are lower than
those for the intrinsic safety type of ignition protection.
Also with regard to errors, lower requirements apply.
Applications
Measuring and monitoring instrumentation and control.
Sensors working on the basis of physical, chemical or mechanical principles and at limited power.
Actuators working on the basis of optical, acoustic and, to a certain extent, mechanical principles.
31
Types of protection

Marking "Ex nR"
Marking "fr"
II 3 G
II 3 G

Principle
The housings are designed in such a way that the ingress of gases is restricted.

The powerloss in the housing may, if it contains sparking components, only lead to a temperature
increase compared to the surrounding of 10 K.
Equipment with these housings must allow monitoring of the vapour tightness and tightness after
installation and maintenance.
The allocation to the temperature class by the external surface temperature applies to all housings
with and without sparking components.
conditions; they must maintain their sealing properties over the service life of the equipment.
Cast seals must permit a permanent operating temperature 10 K compared to the maximum
operating temperature.
Applications
Switchgear, measuring and monitoring instrumentation and information systems and devices.

Marking
"b"
II 2 G/D
Possible principle
By monitoring during normal operation for ignition sources which are not present but might develop,
such as parts warming up, reaction in critical situations is possible. Currently there is the idea to draft
such a standard.

Under construction - must be observed.
Applications
None yet known on the basis of the current development of the standard.
Special protection
Devices which do not fully comply with a type of protection but assure
comparable safety
Marking
"Ex s" II 1/2/3 G
32
Marking
Marking
Contents of the marking
The rules for the marking of systems, devices and components are uniformly defined in the standards
relating to the general technical requirements.
Because the European Community has agreed in the future to also formulate uniform requirements
and to introduce a uniform classification for devices, systems and component, other than electrical
equipment, the marking has also been unified. Additional symbols have been introduced.
This has been defined in the directive 94/9/EC on "Devices and protective systems for use in hazardous
areas".
This directive includes electrical equipment, and for this reason the markings are prefixed by additional
symbols.
The marking on all devices and protective systems for hazardous areas must indicate the area of their
designated use.
Principle
The marking must indicate the following
The manufacturer who has put the item of equipment on the market.
A designation which allows it to be identified.
The application zone underground I
other areas II,
gases and vapours - G -, dust - D - or mines - M The categories which indicate whether the device is only suitable for specific zones.
The type(s) of ignition protection the equipment fulfils.
The explosion group, and if required, the explosion hazard subgroup for which it is suitable and
The temperature class for which the piece of equipment is suitable
The test centre where the test certificate was issued, the standard or revision of a standard applicable
to the piece of equipment including the registration number of the certificate at the test centre, and,
if necessary, which special conditions must be observed.
In addition, the information which is required for a similar device of industrial construction must be
available.
In accordance with EC directive 94/9/EC the future marking for all equipment will be as follows:
0032
II 2 G
in accordance with EC directive 94/9/EC

Conformity mark
0032
notified body who - if required - certified the QA system or the products
The following device groups are distinguished

Device group II
Category / protection level 2
Gases, vapours or mists
other areas
suitable for zone 1
marking with prefix G
33
Marking
Area
Classification of the
explosion hazard
required marking
of the used equipment
Device group
Category
Underground Operation with explosion hazard
M1
Underground Shut down with explosion hazard
M 2 and M 1
other
Zone 0
II
1G
other
Zone 1
II
2G+1G
other
Zone 2
II
3G+2G+1G
other
Zone 20
II
1D
other
Zone 21
II
2D+1D
other
Zone 22
II
3D+2D+1D
Type of ignition protection, explosion group/subgroup and temperature class, conforming to which
the piece of equipment has been produced and is suitable for, will continue to be found using the
marking customary for electrical equipment.
Example of a marking - electrical equipment

BARTEC Type 07-3353-31../.... EEx d IIC T6 PTB ATEX 1065 X
BARTEC Type 07-3353-31../....
EEx d IIC T6
PTB 97 ATEX 1065 X
Manufacturer and
Type designation
Manufactured in accordance with EN 50014 ff
Over ground
Subgroup "C"
Temperature class T6
Symbol of the notified body
Certified 1997
ATEX generation
serial number of notified body
If available - observe special conditions:
e. g. "The light module must be assemble in such a way that
it is mechanically protected from an impact energy in
accordance with EN 60079-0; Section 24.4.2"
Certificate of conformity:
34
PTB 97 ATEX 1065 X

X = special conditions
PTB 97 ATEX 1064 U
U = component certificate - no temperature class
Marking
-Conformity
The following route to CE conformity for electrical apparatus is prescribed
according to EC directive 94/9/EC.
Depending on the conformity category, it defines which path the manufacturer has to follow towards
making the CE conformity declaration. The overview below shows these paths for the different electrical
equipment conformity categories.
Conformity-Assessment-Procedure
Stages to be followed on the way to CE conformity and the CE mark
Devices of group I & II,

category M1 & 11 and
autonomous protection systems
EC type examination certificate
Devices of group II,

category 31
Devices of group I & II,

category M2 & 21
yes
Motor with internal combustion,

electrical devices
no
Internal
production control
and
QA production
or
Product
inspection
EC type examination certificate
EC declaration of
conformity
Conformity
with design
CE mark with
ID number2
and
and
EC declaration of
conformity
or
Internal
production control
QA product
EC declaration of
conformity
Forwarding techn.
documentation
to notified bodies
CE mark without
ID number2
CE mark with
ID number2
EC declaration of
conformity
EC declaration of
conformity
and their components if subject

to a separate certification.
ID number of the notified body, which

certified the QA system or inspected
the products.
EC declaration of
conformity
CE mark without
ID number2
CE mark with
ID number2
CE mark with
ID number2
35
Notice
36
Directive 94/9/EC
Of the european parliament
and the council of 23 March 1994
on the approximation of the laws
of the Member States concerning equipment
and protective systems intended for use
in potentially explosive atmospheres
Directives are subject to variations. The realtime-edition of the directives,

as well their appendices and the guideline for them, you will find under our
homepage www.bartec.de/homepage/atexinfo/index.htm
37
DIRECTIVE 94/9/EC
The european parliament and the council of the european union,

Having regard to the Treaty establishing the European Community, and in
particular Article 100a thereof,
Having regard to the proposal from the Commission 1),
Having regard to the opinion of the Economic and Social Committee 2),
Acting in accordance with the procedure referred to in Article 189b of the
Treaty establishing the European Community;
Whereas it is the duty of Member States to protect, on their territory, the
safety and health of persons and, where appropriate, domestic animals and
property and, in particular, that of workers, especially against the hazards
resulting from the use of equipment and systems providing protection
against potentially explosive atmospheres;
Whereas mandatory provisions within the Member States determine the level
of safety to be achieved by protective equipment and systems intended for
use in potentially explosive atmospheres; whereas these are generally
electrical and non-electrical specifications having an effect on the design
and structure of equipment which can be used in potentially explosive
atmospheres;
Whereas the requirements to be met by such equipment differ from one
Member State to another in respect of their extent and differing inspection
procedures; whereas these differences are, therefore, likely to raise barriers
to trade within the Community;
Whereas harmonization of national legislation is the only way in which to
remove these barriers to free trade; whereas this objective cannot be
satisfactorily achieved by the individual Member States; whereas this Directive
merely lays down the requirements vital to freedom of movement for the
equipment to which it applies;
Whereas the regulations intended to remove technical barriers to trade are
required to follow the new approach provided for in the Council resolution
of 7 May 1985 3), which requires a definition of the essential requirements
regarding safety and other requirements of society without reducing existing,
justified levels of protection within the Member States; whereas that resolution
provides that a very large number of products be covered by a single
Directive in order to avoid frequent amendments and the proliferation of
Directives;
Whereas the existing Directives on the approximation of the laws of the
Member States to electrical equipment for use in potentially explosive
atmospheres have made positive steps towards protection against explosions
via measures linked with the structure of the equipment at issue and which
have helped to remove barriers to trade in this area; whereas, in parallel, a
revision and expansion of the existing Directives is necessary since, more
particularly, in an overall context, action must be taken to guard against the
potential hazards arising from such equipment. This implies in particular
that measures intended to guarantee effective protection of users and third
parties must already be contemplated at the design and manufacturing
states;
Whereas the form taken by the hazard, the protective measures and the test
methods are often very similar, if not identical, for both mining and surface
equipment; whereas it is, therefore, absolutely necessary to cover by a single
Directive protective equipment and systems falling within both groups;
Whereas the two groups of equipment referred to above are used in a large
number of commercial and industrial sectors and possess considerable
economic significance;
1)
2)
3)
4)
5)
OJ No C 46, 20. 2. 1992, p. 19.

OJ No C 106, 27. 4. 1992, p. 9.
OJ No C 136, 4. 6. 1985, p. 1.
OJ No L 109, 26. 4. 1983, p. 8. Directive as last amended
by Directive 88/182/EEC (OJ No L 81, 26. 3. 1988, p. 75).
OJ No L 220, 30. 8. 1993, p. 23.
38
Whereas compliance with the basic safety and health requirements is essential
in order to ensure the safety of protective equipment and systems; whereas
those requirements have been subdivided into general and additional
requirements which must be met by protective equipment and systems;
whereas, in particular, the additional requirements are intended to take
account of existing or potential hazards; whereas protective equipment and
systems will, therefore, embody at least one of those requirements where this
is necessary for their proper functioning or is to apply to their intended use;
whereas the notion of intended use is of prime importance for the explosionproofing of protective equipment and systems; whereas it is essential that
manufacturers supply full information; whereas specific, clear marking of
said equipment, stating its use in a potentially explosive atmosphere, is also
necessary;
Whereas the intention is to prepare a Directive on operations in potentially
explosive atmospheres which is based on Article 118a; whereas that additional
Directive will, in particular, aim at explosion hazards which derive from a
given use and/or types and methods of installation;
Whereas compliance with essential health and safety requirements is
imperative if the safety of equipment is to be ensured; whereas judgment will
have to be exercised in the implementation of those requirements in order to
take account of both the technology obtaining at the time of manufacture and
overriding technical and economic requirements;
Whereas, therefore, this Directive sets out essential requirements only;
whereas, in order to facilitate the task of proving compliance with the
essential requirements, harmonized European standards are necessary,
more especially with regard to the non-electrical aspects of protection
against explosions - standards relating to the design, manufacture and
testing of equipment, compliance with which enables a product to be
presumed to meet such essential requirements; whereas harmonized European
standards are drawn up by private bodies and must retain their nonmandatory status; whereas, for this purpose, the European Committee for
Standardization (CEN) and the European Committee for Electrotechnical
Standardization (Cenelec) are recognized as the bodies competent to adopt
harmonized standards which follow the general guidelines for cooperation
between the Commission and those two bodies, signed on 13 November
1984; whereas, for the purposes of this Directive, a harmonized standard is
a technical specification (European Standard or harmonization document)
adopted by one or other of those bodies, or by both, at the prompting of the
Commission pursuant to Council Directive 83/189/EEC of the 28 March
1983 providing for a procedure governing the provision of information on
technical standards and regulations4) and pursuant to the general guidelines
referred to above;
Whereas the legislative framework should be improved in order to ensure
that employers and workers make an effective and appropriate contribution
towards the standardization process; whereas this should be completed by
the time this Directive is implemented;
Whereas, in view of the nature of the risks involved in the use of equipment
in potentially explosive atmospheres it is necessary to establish procedures
applying to the assessment of compliance with the basic requirements of the
Directives; whereas these procedures must be devised in the light of the level
of risk which may be inherent in equipment and/or against which systems
must protect the immediate environment; whereas, therefore, each category
of equipment conformity must be supplemented by an adequate procedure or
a choice between several equivalent procedures; whereas the procedures
adopted comply fully with Council Decision 93/465/EEC of 22 July 1993
concerning the modules for the various phases of the conformity assessment
procedures which are intended to be used in the technical harmonization
Directives5);
DIRECTIVE 94/9/EC
Whereas the Council has provided for the affixing of the CE marking by either
the manufacturer or his authorized representative within the Community;
whereas that marking means that the product complies with all the basic
requirements and assessment procedures provided for by the Community
law applying to that product;
b)
Whereas it is appropriate that the Member States, as provided for by Article

100a of the Treaty, may take temporary measures to limit or prohibit the
placing on the market and the use of equipment and protective systems in
cases where they present a particular risk to the safety of persons and, where
appropriate, domestic animals or property, provided that the measures are
subject to a Community control procedure;
(c) Components means any item essential to the safe functioning of

equipment and protective systems but with no autonomous function.
Whereas the recipients of any decision taken as part of this Directive must be
aware of the reasons behind that decision and the means of appeal open to
them;
Whereas, on 18 December 1985, the Council adopted a framework Directive
on electrical equipment for use in potentially explosive atmospheres
(76/117/EEC)1) and, on 15 February 1982, a Directive concerning electrical
equipment for use in potentially explosive atmospheres in mines susceptible
to fire damp (82/130/EEC)2); whereas, from the outset of harmonization work,
the conversion into total harmonization of the optional and partial
harmonization on which these Directives are based had been contemplated;
whereas this Directive fully covers the scope of the abovementioned Directives
and whereas, therefore, these Directives must be repealed;
Whereas the internal market incorporates an area without internal frontiers
within which the free movement of goods, persons, services and capital is
assured;
Whereas it is necessary to provide for a transitional arrangement enabling
equipment manufactured in compliance with the national regulations in force
at the date of adoption of this Directive to be marketed and placed in service,
- have adopted this directive:
Chapter I
Explosive atmospheres
Mixture with air, under atmospheric conditions, of flammable substances
in the form of gases, vapours, mists or dusts in which, after ignition has
occurred, combustion spreads to the entire unburned mixture.
Potentially explosive atmosphere
An atmosphere which could become explosive due to local and operational
conditions.
Equipment groups and categories
Equipment group I applies to equipment intended for use in underground
parts of mines, and to those parts of surface installations of such mines,
liable to be endangered by firedamp and/or combustible dust.
Equipment group II applies to equipment intended for use in other places
liable to be endangered by explosive atmospheres.
The categories of equipment defining the required levels of protection are
described in Annex I.
Equipment and protective systems may be designed for a particular explosive
atmosphere. In this case, they must be marked accordingly.
Intended use
The use of equipment, protective systems, and devices referred to in Article
1 (2) in accordance with the equipment group and category and with all the
information supplied by the manufacturer which is required for the safe
functioning of equipment, protective systems and devices.
(4) The following are excluded from the scope of this Directive:
- medical devices intended for use in a medical environment,
Scope, placing on the market and freedom of movement
- equipment and protective systems where the explosion hazard results

exclusively from the presence of explosive substances or unstable
chemical substances,
Article 1
(1) This Directive applies to equipment and protective systems intended for
use in potentially explosive atmospheres.
- equipment intended for use in domestic and non-commercial

environments where potentially explosive atmospheres may only
rarely be created, solely as a result of the accidental leakage of
fuel gas,
(2) Safety devices, controlling devices and regulating devices intended

for use outside potentially explosive atmospheres but required for or
contributing to the safe functioning of equipment and protective systems
with respect to the risks of explosion are also covered by the scope of
this Directive.
- personal protective equipment covered by Directive 89/686/EEC3),

- seagoing vessels and mobile offshore units together with equipment
on board such vessels or units,
(3) For the purposes of this Directive, the following definitions shall apply:
Equipment and protective systems intended for use in potentially
explosive atmospheres
a)
1)
2)
- means of transport, i.e. vehicles and their trailers intended solely for
transporting passengers by air or by road, rail or water networks, as
well as means of transport in so far as such means are designed for
transporting goods by air, by public road or rail networks or by water.
Vehicles intended for use in a potentially explosive atmosphere shall
not be excluded,
Equipment means machines, apparatus, fixed or mobile devices,

control components and instrumentation thereof and detection or
prevention systems which, separately or jointly, are intended for the
generation, transfer, storage, measurement, control and conversion of
energy for the processing of material and which are capable of causing
an explosion through their own potential sources of ignition.

OJ No L 59, 2. 3. 1982, p. 10.
Protective systems means design units which are intended to halt

incipient explosions immediately and/or to limit the effective range of
explosion flames and explosion pressures. Protective systems may be
integrated into equipment or separately placed on the market for use as
autonomous systems.
- the equipment covered by Article 2234) (b) of the Treaty.
3)
4)
OJ No L 399, 30. 12. 1989, p. 18.

39
DIRECTIVE 94/9/EC
Article 2
(1) Member States shall take all appropriate measures to ensure that the
equipment, protective systems and devices referred to in Article 1 (2) to
which this Directive applies may be placed on the market and put into
service only if, when properly installed and maintained and used for
their intended purpose, they do not endanger the health and safety of
persons and, where appropriate, domestic animals or property.
(2) The provisions of this Directive shall not affect Member States
entitlement to lay down, in due observance of the provisions of
the Treaty, such requirements as they may deem necessary to ensure
that persons and, in particular, workers are protected when using the
equipment, protective systems, and devices referred to in Article 1 (2)
in question provided that this does not mean that such equipment,
protective systems, or devices are modified in a way not specified in the
Directive.
(3) At trade fairs, exhibitions, demonstrations, etc., Member States shall
not prevent the showing of equipment, protective systems, or the
devices referred to in Article 1 (2) which do not conform to the
provisions of this Directive, provided that a visible sign clearly indicates
that such equipment, protective systems, and devices referred to in
Article 1 (2) do not conform and that they are not for sale until they have
been brought into conformity by the manufacturer or his authorized
representative established in the Community. During demonstrations,
adequate safety measures shall be taken to ensure the protection of
persons.
Article 3
(2) Where a national standard transposing a harmonized standard, the

reference for which has been published in the Official Journal of the
European Communities, covers one or more of the essential health and
safety requirements, the equipment, protective system, device referred
to in Article 1 (2), or the component referred to in Article 4 (2),
constructed in accordance with that standard shall be presumed to
comply with the relevant essential health and safety requirements.
Member States shall publish the references of national standards
transposing harmonized standards.
(3) Member States shall ensure that appropriate measures are taken to
enable the social partners to influence the process of preparing and
monitoring the harmonized standards at national level.
Article 6
(1) Where a Member State or the Commission considers that the harmonized
standards referred to in Article 5 (2) do not entirely satisfy the relevant
essential health and safety requirements referred to in Article 3, the
Commission or the Member State concerned shall bring the matter
before the Committee set up under Directive 83/189/EEC, hereinafter
referred to as the Committee, giving reasons therefor. The Committee
shall deliver an opinion without delay.
Upon receipt of the Committees opinion, the Commission shall inform
the Member States whether or not it is necessary to withdraw those
standards from the published information referred to in Article 5 (2).
(2) The Commission may adopt any appropriate measure with a view to
ensuring the practical application in a uniform manner of this Directive
in accordance with the procedure laid down in paragraph 3.
Equipment, protective systems, and the devices referred to in Article 1 (2) to

which this Directive applies must meet the essential health and safety
requirements set out in Annex II which apply to them, account being taken of
their intended use.
(3) The Commission shall be assisted by a Standing Committee, consisting

of representatives appointed by the Member States and chaired by a
representative of the Commission.
Article 4
The representative of the Commission shall submit to the Committee a draft

of the measures to be taken. The Committee shall deliver its opinion on the
draft, within a time limit which the chairman may lay down according to the
urgency of the matter, if necessary by taking a vote.
(1) Member States shall not prohibit, restrict or impede the placing on the
market and putting into service in their territory of equipment, protective
systems, or devices referred to in Article 1 (2) which comply with this
Directive.
(2) Member States shall not prohibit, restrict or impede the placing on the
market of components which, accompanied by a certificate of conformity
as referred to in Article 8 (3), are intended to be incorporated into
equipment or protective systems within the meaning of this Directive.
Article 5
(1) Member States shall regard as conforming to all the provisions of this
Directive, including the relevant conformity assessment procedures
laid down in chapter II:
- equipment, protective systems, and devices referred to in Article 1 (2)
accompanied by the EC declaration of conformity referred to in
Annex X and bearing the CE marking provided for in Article 10,
- the components referred to in Article 4 (2), accompanied by the
certificate of conformity referred to in Article 8 (3).
In the absence of harmonized standards, Member States shall take any steps
which they deem necessary to bring to the attention of the parties concerned
the existing national technical standards and specifications regarded as
important or relevant to the proper implementation of the essential health and
safety requirements in Annex II.
The Standing Committee shall draw up its own rules of procedure.
The opinion shall be recorded in the minutes; in addition, each Member State
shall have the right to ask to have its position recorded in the minutes.
The Commission shall take the utmost account of the opinion delivered by
the committee. It shall inform the committee of the manner in which its
opinion has been taken into account.
(4) The Standing Committee may furthermore examine any question relating
to the application of this Directive and raised by its chairman either on
the latters initiative, or at the request of a Member State.
Article 7
(1) Whee a Member State ascertains that equipment, protective systems or
devices referred to in Article 1 (2) bearing the CE conformity marking
and used in accordance with their intended use are liable to endanger
the safety of persons and, where appropriate, domestic animals or
property, it shall take all appropriate meaures to withdraw such equipment
or protective systems from the market, to prohibit the placing on the
market, putting into service or use thereof, or to restrict free movement
there of. The Member State shall immediately inform the Commission
of any such measure, indicating the reasons for its decision and, in
particular, whether non-conformity is due to:
(a) failure to satisfy the essential requirements referred to in Article 3;
(b) incorrect application of the standards referred to in Article 5 (2);
(c) shortcomings in the standards referred to in Article 5 (2).
40
DIRECTIVE 94/9/EC
(2) The Commission shall enter into consultation with the parties concerned
without delay. Where the Commission considers, after this Consultation,
that the measure is justified, it shall immediately so inform the Member
State which took the initiative and the other Member States. Where the
Commission considers, after this consultation, that the action is
unjustified, it shall immediately so inform the Member State which took
the initiative and the manufacturer or his authorized representative
established within the Community. Where the decision referred to in
paragraph 1 is based on a shortcoming in the standards and where the
Member State at the origin of the decision maintains its position, the
Commission shall immediately inform the Committee in order to
initiate the procedures referred to in Article 6 (1).
c)
(3) Where equipment or a protective system which does not comply bears
the CE conformity marking, the competent Member State shall take
appropriate action against the person(s) having affixed the marking and
shall so inform the Commission and the other Member States.
(3) The procedures referred to in paragraph 1 shall be applied in respect of

components as referred to in Article 4 (2), with the exception of the
affixing of the CE marking. A certificate shall be issued by the
manufacturer or his authorized representative established in the
Community, declaring the conformity of the components with the
provisions of this Directive which apply to them and stating their
characteristics and how they must be incorporated into equipment or
protective systems to assist compliance with the essential requirements
applicable to finished equipment or protective systems.
(4) The Commission shall ensure that the Member States are kept informed
of the progress and outcome of this procedure.
Chapter II
Conformity assessment procedures
Article 8
(1) The procedures for assessing the conformity of equipment, including
where necessary the devices referred to in Article 1 (2), shall be as
follows:
a)
equipment-group I and II, equipment-category M 1 and 1.

The manufacturer or his authorized representative established in the
Community must, in order to affix the CE marking, follow the CE typeexamination procedure (referred to in Annex III), in conjunction with:
- the procedure relating to production quality assurance (referred
to in Annex IV),
or
- the procedure relating to product verification (referred to in Annex V);
b)
Equipment-group I and II, equipment-category M 2 and 2
i)
In the case of internal combustion engines and electrical equipment in

these groups and categories, the manufacturer or his authorized
representative established in the Community shall, in order to affix the
CE mark, follow the EC-type examination procedure (referred
to in Annex III), in conjunction with:
- the procedure relating to conformity to type referred to in Annex VI,
or
- the procedure relating to product quality assurance referred to in
Annex VII;
ii)
In the case of other equipment in these groups and categories, the

manufacturer or his authorized representative established in the
Community must, in order to affix the CE mark, follow the procedure
relating to internal control of production (referred to in Annex VIII) and
communicate the dossier provided for in Annex VIII, paragraph 3, to a
notified body, which shall acknowledge receipt of it as soon as possible
and shall retain it.
equipment-group II, equipment-category 3

The manufacturer or his authorized representative established in the
Community must, in order to affix the CE marking, follow the procedure
relating to internal control of production referred to n Annex VIII;
d)
equipment-groups I and II
In addition to the procedures referred to in paragraph 1(a), (b) and (c),
the manufacturer or his authorized representative established in the
Community may also, in order to affix the CE marking, follow the
procedure relating to CE unit verification (referred to in Annex IX).
(2) The provisions of 1(a) or 1(d) above shall be used for conformity
assessment of autonomous protective systems.
(4) In addition, the manufacturer or his authorized representative established

in the Community may, in order to affix the CE marking, follow the
procedure relating to internal control of production (referred to in
Annex VIII) with regard to the safety aspects referred to in point 1.2.7 of
Annex II.
(5) Notwithstanding the previous paragraphs, the competent authorities
may, on a duly justified request, authorize the placing on the market and
putting into service on the territory of the Member State concerned of
the equipment, protective systems and individual devices referred to in
Article 1 (2) in respect of which the procedures referred to in the
previous paragraphs have not been applied and the use of which is in
the interests of protection.
(6) Documents and correspondence relating to the procedures referred to
in the abovementioned paragraphs shall be drawn up in one of the
official languages of the Member States in which those procedures are
being applied or in a language accepted by the notified body.
(7) (a) Where the equipment and protective systems are subject to other
Community Directives covering other aspects which also provide
for the affixing of the CE marking referred to in Article 10, that
marking shall indicate that the equipment and protective systems
are also presumed to conform with the provisions of those other
Directives.
(b) However, where one or more of those Directives allow the
manufacturer, during a transitional period, to choose which
arrangements to apply, the CE marking shall indicate conformity
only with the Directives applied by the manufacturer. In this case,
particulars of the said Directives, as published in the Official Journal
of the European Communities, must be given in the documents,
notices or instructions required by the Directives and accompanying
the equipment and protective systems.
41
DIRECTIVE 94/9/EC
Article 9
Article 13
(1) Member States shall notify the Commission and the other Member
States of the bodies which they have appointed to carry out the
procedures referred to in Article 8, together with the specific tasks
which these bodies have been appointed to carry out and the identification
numbers assigned to them beforehand by the Commission. The
Commission shall publish in the Official Journal of the European
Communities a list of the notified bodies, with their identification
numbers and the tasks for which they have been notified. The Commission
shall ensure that this list is kept up to date.
(2) Member States shall apply the criteria laid down in Annex XI in
assessing the bodies to be indicated in such notification. Bodies
meeting the assessment criteria laid down in the relative harmonized
standards shall be presumed to fulfil those criteria.
Member States shall ensure that all the parties involved in the application of
the Directive are bound to observe confidentiality in respect of all information
obtained in the performance of carrying out their tasks. This does not affect
the obligations of the Member States and of the notified bodies regarding
reciprocal information and the dissemination of warnings.
(3) A Member State which has approved a body must withdraw its notification
if it finds that the body no longer meets the criteria referred to in
Annex XI. It shall immediately inform the Commission and the other
Member States accordingly.
Chapter III CE
conformity marking
Article 10
(1) The CE conformity marking shall consist of the initials CE. The form
of the marking to be used is shown in Annex X. The CE marking shall
be followed by the identification number of the notified body where such
body is involved in the production control stage.
(2) The CE marking shall be affixed distinctly, visibly, legibly and indelibly
to equipment and protective systems, supplementary to the provisions
of point 1.0.5. of Annex II.
(3) The affixing of markings on the equipment or protective systems which
are likely to deceive third parties as to the meaning and form of the CE
marking shall be prohibited. Any other marking may be affixed to the
equipment or protective systems, provided that the visibility and legibility
of the CE marking is not thereby reduced.
Article 11
Without prejudice to Article 7:
a)
b)
where a Member State establishes that the CE marking has been

incorrectly affixed, the manufacturer or his authorized representative
established within the Community shall be obliged to make the product
conform as regards the provisions concerning the CE marking and to
end the infringement under the conditions imposed by the Member
State;
in the event of continuing non-conformity, the Member State must take
all appropriate measures to restrict or prohibit the placing on the market
of the product in question or to ensure that it is withdrawn from the
market in accordance with the procedures laid down in Article 7.
Article 14
(1) Directive 76/117/EEC, Directive 79/196/EEC (1) and Directive 82/130/
EEC shall be repealed as from 1 July 2003.
(2) EC certificates of conformity to the harmonized standards obtained in
accordance with the procedures laid down in the Directives referred to
in paragraph 1 shall continue to be valid until 30 June 2003 unless they
expire before that date. Their validity shall continue to be limited to the
harmonized standards indicated in the aforementioned Directives.
(3) Member States shall take the necessary action to ensure that the notified
bodies which are responsible pursuant to Article 8 (1) to (4) for the
assessment of the conformity of electrical equipment placed on the
market before 1 July 2003 take account of the results of tests and
verifications already carried out under the Directives referred to in
paragraph 1.
Article 15
(1) Member States shall adopt and publish the laws, regulations and
administrative provisions necessary to comply with this Directive
before 1 September 1995. They shall forthwith inform the Commission
thereof. The Member States shall apply these measures with effect from
1 March 1996. When Member States adopt the measures referred to in
the first subparagraph, they shall contain a reference to this Directive or
shall be accompanied by such reference at the time of their official
publication. The methods of making such reference shall be laid down
by Member States.
(2) However, Member States shall allow the placing on the market and the
putting into service of equipment and protective systems conforming
with the national regulations in force in their territory at the date of
adoption of this Directive for the period until 30 June 2003.
Article 16
This Directive is addressed to the Member States.
Done at Brussels, 23 March 1994.
For the European Parliament
The President
E. KLEPSCH
For the Council
The President
TH. PANGALOS
CHAPTER IV
Final provisions
Article 12
Any decision taken pursuant to this Directive which restricts or prohibits the
placing on the market and/or the putting into service or requires the
withdrawal from the market of equipment, a protective system, or a device
referred to in Article 1 (2) shall state the exact grounds on which it is based.
Such a decision shall be notified forthwith to the party concerned, who shall
at the same time be informed of the legal remedies available to him under the
laws in force in the Member State concerned and of the time limits to which
such remedies are subject.
42
The appendices you will find under

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Directive1999/92/EC
Of the european parliament
and the council of 16 December 1999
on minimum requirements for improving
the safety and health protection of workers
potentially at risk from explosive atmospheres
(15th individual Directive within the meaning of
Article 16(1) of Directive 89/391/EEC)
Directives are subject to variations. The realtime-edition of the directives,

as well their appendices and the guideline for them, you will find under our
homepage www.bartec.de/homepage/atexinfo/index.htm
43
DIRECTIVE 1999/92/EC
The european parliament and the council of the european union,

Having regard to the Treaty establishing the European Community, and in
particular Article 137 thereof,
Having regard to the proposal from the Commission1), submitted after
consultation with the Advisory Committee on Safety, Hygiene and Health
Protection at Work and the Safety and Health Commission for the Mining and
Other Extractive Industries, Having regard to the opinion of the Economic
and Social Committee2), After consulting the Committee of the Regions,
Acting in accordance with the procedure referred to in Article 251 of the
Treaty, in the light of the joint text approved by the Conciliation Committee
on 21 October 19993), Whereas:
(1) Article 137 of the Treaty provides that the Council may adopt, by means
of Directives, minimum requirements for encouraging improvements,
especially in the working environment, to guarantee a better level of
protection of the health and safety of workers;
(2) Under the terms of that Article, those Directives are to avoid imposing
administrative, financial and legal constraints in a way which would
hold back the creation and development of small and medium-sized
undertakings;
(3) The improvement of occupational safety, hygiene and health is an
objective which should not be subordinated to purely economic
considerations;
(4) Compliance with the minimum requirements for improving the safety
and health protection of workers potentially at risk from explosive
atmospheres is essential if workers safety and health protection is to be
ensured;
(5) This Directive is an individual Directive within the meaning of Article
16(1) of Council Directive 89/391/EEC of 12 June 1989 on the
introduction of measures to encourage improvements in the safety and
health of workers at work 4); therefore, the provisions of the said
Directive, in particular those relating to worker information, to the
consultation and participation of workers and to the training of workers,
are also fully applicable to cases in which workers are potentially at risk
from explosive atmospheres, without prejudice to more restrictive or
specific provisions contained in this Directive;
(6) This Directive constitutes a practical step towards the achievement of
the social dimension of the internal market;
(7) Directive 94/9/EC of the European Parliament and of the Council of 23
March 1994 on the approximation of the laws of the Member States
concerning equipment and protective systems intended for use in
potentially explosive atmospheres5) states that it is intended to prepare
an additional Directive based on Article 137 of the Treaty covering, in
particular, explosion hazards which derive from a given use and/or
types and methods of installation of equipment;
1)
2)
3)
4)
5)
6)
OJ C 332, 9.12.1995, p. 10 and OJ C 184, 17.6.1997, p. 1.

OJ C 153, 28.5.1996, p. 35.
Opinion of the European Parliament of 20 June 1996
(OJ C 198, 8.7.1996, p. 160) confirmed on 4 May 1999
(OJ C 279, 1.10.1999, p 55), Council Common Position of 22 December 1998
(OJ C 55, 25.2.1999, p. 45), Decision of the European Parliament of 6 May 1999
(OJ C 279, 1.10.1999, p. 386). Decision of the European Parliament
of 2 December 1999 and Council Decision of 6 December 1999.
OJ L 183, 29.6.1989, p. 1.
OJ L 100, 19.4.1994, p. 1.
OJ L 245, 26.8.1992, p. 23
44
(8) Explosion protection is of particular importance to safety; whereas

explosions endanger the lives and health of workers as a result of the
uncontrolled effects of flame and pressure, the presence of noxious
reactin products and consumption of the oxygen in the ambient air
which workers need to breathe;
(9) The establishment of a coherent strategy for the prevention of explosions
requires that organisational measures complement the technical
measures taken at the workplace; Directive 89/391/EEC requires the
employer to be in possession of an assessment of the risks to workers
health and safety at work; this requirement is to be regarded as being
specified by this Directive in that it provides that the employer is to draw
up an explosion protection document, or set of documents, which
satisfies the minimum requirements laid down in this Directive and is
to keep it up to date; the explosion protection document includes the
identification of the hazards, the evaluation of risks and the definition
o
f
the specific measures to be taken to safeguard the health and safety of
workers at risk from explosive atmospheres, in accordance with Article
9 of Directive 89/391/EEC; the explosion protection document may be
part of the assessment of the risks to health and safety at work required
by Article 9 of Directive 89/391/EEC;
(10) An assessment of explosion risks may be required under other
Community acts; whereas, in order to avoid unnecessary duplication of
work, the employer should be allowed, in accordance with national
practice, to combine documents, parts of documents or other equivalent
reports produced under other Community acts to form a single
safety report;
(11) The prevention of the formation of explosive atmospheres also includes
the application of the substitution principle;
(12) Coordination should take place when workers from several undertakings
are present at the same workplace;
(13) Preventive measures must be supplemented if necessary by additional
measures which become effective when ignition has taken place;
maximum safety can be achieved by combining preventive measures
with other additional measures limiting the detrimental effects of
explosions on workers;
(14) Council Directive 92/58/EEC of 24 June 1992 on the minimum
requirements for the provision of safety and/or health signs at work
(ninth individual Directive within the meaning of Article 16(1) of
Directive 89/391/EEC)6) is fully applicable, in particular to places
immediately contiguous to hazardous areas, where smoking,
crosscutting, welding and other activities introducing flames or sparks
may interact with the hazardous area;
(15) Directive 94/9/EC divides the equipment and protective systems which
it covers into equipment groups and categories; this Directive provides
for a classification by the employer of the places where explosive
atmospheres may occur in terms of zones and determines which
equipment and protective systems groups and categories should be
used in each zone,
- have adopted this directive:
Article 4
Section I
GENERAL PROVISIONS
Assessment of explosion risks
Article 1
Object and scope
(1) This Directive, which is the 15th individual Directive within the meaning
of Article 16(1) of Directive 89/391/EEC, lays down minimum
requirements for the safety and health protection of workers potentially
at risk from explosive atmospheres as defined in Article 2.
(2) This Directive shall not apply to:
(1) In carrying out the obligations laid down in Articles 6(3) and 9(1) of
Directive 89/391/EEC the employer shall assess the specific risks
arising from explosive atmospheres, taking account at least of:
- the likelihood that explosive atmospheres will occur and their
persistence,
- the likelihood that ignition sources, including electrostatic discharges,
will be present and become active and effective,
- the installations, substances used, processes, and their possible
interactions,
a)
areas used directly for and during the medical treatment of patients;
b)
the use of appliances burning gaseous fuels in accordance with

Directive 90/396/EEC1);
c)
the manufacture, handling, use, storage and transport of explosives or

chemically unstable substances;
(2) Places which are or can be connected via openings to places in which
explosive atmospheres may occur shall be taken into account in
assessing explosion risks.
d)
mineral-extracting industries covered by Directive 92/91/EEC2) or

Directive 92/104/EEC3);
Article 5
e)
the use of means of transport by land, water and air, to which the
pertinent provisions of the international agreements (e.g. ADNR, ADR,
ICAO, IMO, RID), and the Community Directives giving effect to those
agreements, apply. Means of transport intended for use in a potentially
explosive atmosphere shall not be excluded.
(3) The provisions of Directive 89/391/EEC and the relevant individual

Directives are fully applicable to the domain referred to in paragraph 1,
without prejudice to more restrictive and/or specific provisions contained
in this Directive.
Article 2
Definition
For the purposes of this Directive, explosive atmosphere means a mixture
with air, under atmospheric conditions, of flammable substances in the form
of gases, vapours, mists or dusts in which, after ignition has occurred,
combustion spreads to the entire unburned mixture.
Section II
Obligations of the employer
Article 3
Prevention of and protection against explosions
With a view to preventing, within the meaning of Article 6(2) of Directive 89/
391/EEC, and providing protection against explosions, the employer shall
take technical and/or organisational measures appropriate to the nature of
the operation, in order of priority and in accordance with the following basic
principles:
- the prevention of the formation of explosive atmospheres, or where
the nature of the activity does not allow that,
- the avoidance of the ignition of explosive atmospheres, and
- the mitigation of the detrimental effects of an explosion so as to
ensure the health and safety of workers.
These measures shall where necessary be combined and/or supplemented
with measures against the propagation of explosions and shall be reviewed
regularly and, in any event, whenever significant changes occur.
1)
2)
3)
- the scale of the anticipated effects.

Explosion risks shall be assessed overall.
General obligations
To ensure the safety and health of workers, and in accordance with the basic
principles of risk assessment and those laid down in Article 3, the employer
shall take the necessary measures so that:
- where explosive atmospheres may arise in such quantities as to
endanger the health and safety of workers or others, the working
environment is such that work can be performed safely,
- in working environments where explosive atmospheres may arise in
such quantities as to endanger the safety and health of workers,
appropriate supervision during the presence of workers is ensured in
accordance with the risk assessment by the use of appropriate technical
means.
Article 6
Duty of coordination
Where workers from several undertakings are present at the same workplace,
each employer shall be responsible for all matters coming under his control.
Without prejudice to the individual responsibility of each employer as
provided for in Directive 89/391/EEC, the employer responsible for the
workplace in accordance with national law and/or practice shall coordinate
the implementation of all the measures concerning workers health and safety
and shall state, in the explosion protection document referred to in Article 8,
the aim of that coordination and the measures and procedures for implementing
it.
Article 7
Places where explosive atmospheres may occur
(1) The employer shall classify places where explosive atmospheres may
occur into zones in accordance with Annex I.
(2) The employer shall ensure that the minimum requirements laid down in
Annex II are applied to places covered by paragraph 1.
(3) Where necessary, places where explosive atmospheres may occur in
such quantities as to endanger the health and safety of workers shall be
marked with signs at their points of entry in accordance with Annex III.
OJ L 196, 26.7.1990, p. 15. Directive as amended by Directive 93/68/EEC

(OJ L 220, 30.8.1993, p. 1).
OJ L 348, 28.11.1992, p. 9.
OJ L 404, 31.12.1992, p. 10.
45
Article 8
Explosion protection document
Section III
Miscellaneous privisions
In carrying out the obligations laid down in Article 4, the employer shall
ensure that a document, hereinafter referred to as the explosion protection
document, is drawn up and kept up to date.
Article 10
The explosion protection document shall demonstrate in particular:
Purely technical adjustments to the annexes made necessary by:

- the adoption of Directives on technical harmonisation and
standardisation in the field of explosion protection, and/or
- technical progress, changes in international regulations or
specifications, and new findings on the prevention of and protection
against explosions, shall be adopted in accordance with the procedure
laid down in Article 17 of Directive 89/391/EEC.
- that the explosion risks have been determined and assessed,

- that adequate measures will be taken to attain the aims of this
Directive,
- those places which have been classified into zones in accordance with
Annex I,
Adjustments to the annexes
- those places where the minimum requirements set out in Annex II will
apply,
Article 11
- that the workplace and work equipment, including warning devices,

are designed, operated and maintained with due regard for safety,
The Commission shall draw up practical guidelines in a guide of good

practice of a non-binding nature. This guide shall address the topics referred
to in Articles 3, 4, 5, 6, 7 and 8, Annex I and Annex II, Part A.
The Commission shall first consult the Advisory Committee on Safety,
Hygiene and Health Protection at Work in accordance with Council Decision
74/325/EEC 2).
In the context of the application of this Directive, Member States shall take
the greatest possible account of the abovementioned guide in drawing up
their national policies for the protection of the health and safety of workers
- that in accordance with Council Directive 89/655/EEC 1) ,

arrangements have been made for the safe use of work equipment.
The explosion protection document shall be drawn up prior to the
commencement of work and be revised when the workplace, work equipment
or organisation of the work undergoes significant changes, extensions or
conversions.
The employer may combine existing explosion risk assessments, documents
or other equivalent reports produced under other Community acts.
Guide of good practice
Article 12
Article 9
Information to undertakings
Special requirements for work equipment and workplaces
Member States shall, on request, endeavour to make relevant information

available to employers in accordance with Article 11, with particular reference
to the guide of good practice
(1) Work equipment for use in places where explosive atmospheres may
occur which is already in use or is made available in the undertaking or
establishment for the first time before 30 June 2003 shall comply from
that date with the minimum requirements laid down in Annex II, Part A,
if no other Community Directive is applicable or is so only partially.
(2) Work equipment for use in places where explosive atmospheres may
occur which is made available in the undertaking or establishment for
the first time after 30 June 2003 shall comply with the minimum
requirements laid down in Annex II, Parts A and B.
(3) Workplaces which contain places where explosive atmospheres may
occur and which are used for the first time after 30 June 2003 shall
comply with minimum requirements set out in this Directive.
(4) Where workplaces which contain places where explosive atmospheres
may occur are already in use before 30 June 2003, they shall comply
with the minimum requirements set out in this Directive no later than
three years after that date.
(5) If, after 30 June 2003, any modification, extension or restructuring is
undertaken in workplaces containing places where explosive
atmospheres may occur, the employer shall take the necessary steps to
ensure that these comply with the minimum requirements set out in this
Directive.
Article 13
Final provisions
(1) Member States shall bring into force the laws, regulations and
administrative provisions necessary to comply with this Directive not
later than 30 June 2003. They shall forthwith inform the Commission
there of.
When Member States adopt these measures, they shall contain a
reference to this Directive or shall be accompanied by such reference on
the occasion of their official publication. The methods of making such
reference shall be laid down by the Member States.
(2) Member States shall communicate to the Commission the text of the
provisions of domestic law which they have already adopted or adopt in
the field governed by this Directive.
(3) Member States shall report to the Commission every five years on the
practical implementation of the provisions of this Directive, indicating
the points of view of employers and workers. The Commission shall
inform thereof the European Parliament, the Council, the Economic and
Social Committee and the Advisory Committee on Safety, Hygiene and
Health Protection at Work.
Article 14
This Directive shall enter into force on the day of its publication in the Official
Journal of the European Communities.
Article 15
This Directive is addressed to the Member States.
Done at Brussels, 16 December 1999.
For the European Parliament
The President
N. FONTAINE
1)
2)
OJ L 393, 30.12.1989, p. 13. Directive as amended by Directive 95/63/EC

(OJ L 335, 30.12.1995, p. 28).
OJ L 185, 9.7.1974, p. 15. Decision as last amended by the 1994 Act of Accession.
46
For the Council

The President
K. HEMIL
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BARTEC Engineering + Services AG

Hinterbergstrasse 28
CH-6330 Cham
Phone +41 41 747 27-27
Fax
+41 41 747 27-28
e-mail info@bartec.ch
web
www.bartec.ch
BACAB SA
Rue de Iindustrie 19
CH-1450 Sainte-Croix
Phone +41 24 454 40 80
Fax
+41 24 454 40 88
e-mail info@bacab.ch
web
www.bacab.ch
BARTEC POLSKA Sp.zo.o.

ul Bp. Burschego 3
PL 43-100 Tychy
Phone +48 32 326 44 00
Fax
+48 32 327 14 59
e-mail bartecpolska@bartec.pl
web
www.bartec.pl
Czech Republic/Prague
Austria/Vienna
Slovenia/Zagorje ob Savi
Spain/Barcelona
BARTEC s.r.o.
Pacovsk 869/31
CZ-140 00 Praha 4
Phone +420 2417 34033
Fax
+420 2417 34026
e-mail bartec@bartec.cz
web
www.bartec.cz
BARTEC Elektrotechnik GmbH

Jochen-Rindt-Strae 41
A-1230 Wien
Phone +43 1 6163520-0
Fax
+43 1 6163520-33
e-mail office@bartec.at
web
www.bartec.at
BARTEC d.o.o.
Cesta 9, avgusta 59
SLO-1410 Zagorje ob Savi
Phone +386 356 643-66
Fax
+386 356 642-34
e-mail info@bartec-varnost.si
web
www.bartec-varnost.si
BARTEC S.A.
Pasaje del Congost 19,Entlo.
E-08903 LHospitalet del Llobregat,
Barcelona
Phone +34-93-3 31 42 58
Fax
+34-93-3 31 44 63
e-mail ventas@bartec.es
web
www.bartec.es
Italy/Melegnano
Representative offices:
Bulgaria/Sofia, Estonia/Tallinn, Greece/Athen, Ireland/Cork,
Lituania/Vilnius, Poland/Warschau, Portugal/Cacm, Rumania/Bukarest,
Russia/Moskau, Slovenia/Bratislava, Hungary/Budapest
BARTEC s.r.l.
Via per Carpiano, 8/10
I-20077 Melegnano (Mi)
Phone +39 0298 23 19 91
Fax
+39 0298 23 19 96
e-mail info@bartec.it
web
www.bartec.it
48
Germany
America
Hamburg/Reinbek
Cologne
Menden
Hamburg/Reinbek
BARTEC GmbH
Technisches Bro Hamburg
Borsigstrae 10
D-21465 Reinbek/Hamburg
Phone +49 40 80 99 41-0
Fax
+49 40 80 99 41-79
e-mail tb.hamburg@bartec.de
BARTEC GmbH
Technisches Bro Kln
Industriestrae 155
D-50999 Kln (Rodenkirchen)
Phone +49 2236 9 66 78-0
Fax
+49 2236 9 66 78-23
e-mail tb.koeln@bartec.de
BARTEC
Sicherheits-Schaltanlagen GmbH
Holzener Strae 35-37
D-58708 Menden
Phone +49 2373 684-0
Fax
+49 2373 684-209
e-mail info@me.bartec.de
Region Nord
BARTEC BENKE GmbH
Borsigstrae 10
D-21465 Reinbek/Hamburg
Phone +49 40 72703-0
Fax
+49 40 72703-228
e-mail BueroNord@bartec-benke.de
Frankfurt/Main
Bad Mergentheim
Frankfurt
Gotteszell
BARTEC GmbH
Technisches Bro Frankfurt
Berner Strae 53
D-60437 Frankfurt
Phone +49 69 500 04-0
Fax
+49 69 500 04-199
e-mail tb.frankfurt@bartec.de
BARTEC GmbH
Technisches Bro Sd-West
Max-Eyth-Strae 16
D-97980 Bad Mergentheim
Phone +49 7931 597-218
Fax
+49 7931 597-445
e-mail info@bartec.de
Region Mitte
BARTEC BENKE GmbH
Berner Strae 53
D-60437 Frankfurt
Phone +49 69 500 04-0
Fax
+49 69 500 04-199
e-mail BueroMitte@bartec-benke.de
BARTEC GmbH
Schulstrae 30
D-94239 Gotteszell
Phone +49 9929 301-0
Fax
+49 9929 301-112
e-mail info@go.bartec.de
Leipzig/Bhlen
Cologne/Marl
Region Ost
BARTEC BENKE GmbH
Werkstrae
Postfach 24
D-04564 Bhlen
Phone +49 34206 605-0
Fax
+49 34206 605-60
e-mail BueroBoehlen@bartecbenke.de
Region West
BARTEC BENKE GmbH
Chemiepark Marl
im Fremdfirmenbaufeld (Tor 6)
Paul-Baumann-Strae 1
D-45764 Marl
Phone +49 2365 495-559
Fax
+49 2365 495-265
e-mail BueroWest@bartec-benke.de
USA/Tulsa
BARTEC US Corp.
9902 - E East 43 rd St.
USA-Tulsa, OK 74146
Phone +1 918 627 1889
Fax
+1 918 627 1890
e-mail info@bartecus.com
web
www.bartecus.com
Africa
South Africa/Johannesburg
BARTEC Barlian S.A. (PTY), Ltd.
Box 58071
NEWVILLE
ZA 2114
Phone +27-11-673 40 84
Fax
+27-11-673 17 72
e-mail info@bartec.co.za
web
www.bartec.co.za
Asia
Argentinia/Bahia Blanca, Brazil/So Paulo, Rio de Janeiro,
Chile/Santiago, Canada/Calgary, Canada/Toronto, Mexico/Mexiko City,
Venezuela/Caracas
Nigeria/Lagos
Singapore/Singapore
China/Shanghai
China/Shanxi
Malaysia/Ampang
BARTEC Pte. Ltd.

No.63 Hillview Avenue
# 07-20/21 Lam Soon Ind. Bldg.
SGP-Singapore 669569
Phone +65 6762 5030
Fax
+65 6762 5031
e-mail info@bartecasia.com
web
www.bartecasia.com
BARTEC Electric (Shanghai) Co. Ltd.

Rm 12F, West Tower
Shanghai Hi-Tech King City
No. 666 Beijing East Road
CN - 200001Shanghai
Phone +86 21 5356 0100
Fax
+86 21 5308 5900
e-mail info@bartec.com.cn
web
www.bartec.com.cn
BARTEC Electric (Shanxi) Co. Ltd.

No. 1 chengbeijie
CN - 046011 changzhi, Shanxi
Phone +86 355 2613592
Fax
+86 355 2613592
e-mail
bartecshanxi@bartec.com.cn
BARTEC Services & Engineering

Sdn. Bhd.
12th Floor, MUI Plaza
Jalan P. Ramlee
50250 Kuala Lumpur
Malaysia
Phone +60 (3) 2145 2488
Fax
+60 (3) 2145 6299
e-mail malaysia@bartecasia.com
Brunei/Darussalam, China/Beijing, China/Guangzhou, India/Mumbai, Indonesia/Jakarta, Iran/Tehran, Iran/Isfahan, Israel/Petach Tikva, Japan/Tokyo,
Korea/Seoul, Kowloon/Hong Kong, Kuwait/Safat, Macau/Macau, Malaysia/Kuala Lumpur, Philippines/Manila, Qatar/Doha, Saudi Arabia/Damman, Sultanat
Oman/Ruwi, Taiwan/Kaohsiung, Thailand/Bangkok, Turkey/Istanbul, United Arab Emirates/Abu Dhabi, Dubai, Vietnam/Ho-Chi-Min town
Australia/
New Zealand
Representative office: Australia/Melbourne, New Zealand/Auckland
1200 BARTECians worldwide are committed to safety technology: www.bartec.de
BARTEC protects
people
and
the environment
by the safety
of components,
s y s t e m s
BARTEC GmbH
plants.
Max-Eyth-Strae 16
97980 Bad Mergentheim
Phone: +49 7931 597-0

Fax: +49 7931 597-119
E-mail: info@bartec.de
Internet: www.bartec.de
UK-D-EXC700197-03/05-BARTEC WerbeAgentur-126172
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Basics of Explosion Protection - Bartec

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Basics of Explosion Protection - Bartec

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Basic concepts for explosion protection

A leading position for safety engineering

Technical development of explosion protection

After bitter experiences in the beginning, mine explosions were able

Today, fortunately, the number of accidents caused by electrical

All those involved

Priority over the solutions referring to the ignition source is given

Our corporate goal is:

BARTEC protects people and the environment

Basis for an explosion

Primary explosion protection

Prevention of ignition sources

Designed to design regulations

Approval by an accredited organisation

Quality assurance system in operation in

Manufacturer Routine tests

Installation in conformity with the

Commissioning e. g. by an accredited expert

Maintenance and inspection by safety engineering

1. Potentially explosive mixtures can penetrate

Enclosed break device

2. The item of equipment is provided with an

Gases and dust

Restricted breathing enclosure

Hermetically sealed device

3. Potentially explosive mixtures can penetrate the

4. Potentially explosive mixtures can penetrate the

Gases and dust

Energy limited circuit

Protection by constructional safety

Design regulations for explosion protected systems,

Explosive atmospheres - Explosion prevention and protection

Explosive atmospheres - Explosion prevention and protection

Potentially explosive atmospheres - Explosion prevention and protection

Determination of the maximum explosion pressure and maximum rate

Determination of the maximum explosion pressure and maximum rate

Electrical apparatus for explosive gas atmosphere

Electrical apparatus for explosive gas atmosphere

Electrical apparatus for explosive gas atmospheres

Electrical apparatus for explosive gas atmospheres

Electrical apparatus for explosive gas atmosphere

IEC 60079-4 AMD1

Testing of mineral oil hydrocarbons

Electrical apparatus for use in the presence of combustible dust

Electrical apparatus for use in the presence of combustible dust

Electrical apparatus for use in the presence of combustible dust;

Electrical apparatus for use in the presence of combustible dust

Electrical apparatus for use in presence of combustible dust

Characteristics of combustible gases and vapours

Characteristics of combustible dusts

Classification of hazardous areas with combustible gases and vapours

combustible gases and vapours

Electrical apparatus for explosive gas atmospheres

prEN 60079-1; 2002

Electrical apparatus for explosive gas atmospheres

Electrical apparatus for explosive gas atmospheres

Electrical apparatus for explosive atmospheres

Electrical apparatus for explosive gas atmospheres

Electrical apparatus for explosive gas atmospheres