Thirty-Fourth Session Bangkok, Thailand, 8 - 13 October 2001
Thirty-Fourth Session Bangkok, Thailand, 8 - 13 October 2001
Thirty-Fourth Session Bangkok, Thailand, 8 - 13 October 2001
July 2001
Background
• It is difficult to evaluate hazards associated with pests of food. Certain species of flies,
cockroaches and rodents are contributing factors to the spread of food-borne illness
because they are natural vectors of pathogens such as Shigella, Salmonella Enteritidis,
Escherichia coli O157:H7, Campylobacter jejuni and the parasite Cryptosporidium
parvum. Only a small number of pest species carry these pathogens and transmit them
to humans or human food; further, these same species do not transmit disease all the
time but only under certain circumstances. Telling the difference between a disease
vector and a pest that is not a vector is difficult but very important. There is additional
difficulty in identifying the conditions under which vectors transmit pathogen hazards to
consumers. Supplemental guidance is needed to identify and evaluate the conditions
under which pests are reasonably likely to represent a contributing factor to a microbial
hazard.
• Allergenic mites are a discrete food safety issue. Recent studies in Asia, Europe and
North America report life-threatening allergic reactions due to the consumption of food
contaminated with allergenic mites (see Annex 2 - Summary of the Science Basis).
Preventing hazards from mite allergens is more difficult than preventing hazards from
allergenic food ingredients because the etiologies of the two types of allergens are
different. Mite allergens are a result of environmental contamination while inadvertent
ingredient allergens are the result of unintentionally adding an ingredient to a food
during production. Separate guidance is required because the controls for preventing
injury from ingredient allergens are not effective in preventing environmental
contamination by food-infesting allergenic mites.
4. The purposes of the proposed guidelines are several. The proposed guidelines will:
• Assist in explaining how to implement the provisions of the GPFH with respect to
hazards from objectionable matter and pest exclusion.
• Assist pest control operators in forming accurate evaluations of the health significance
of pest activity and thus helping to reduce indiscriminate or unnecessary use of
pesticides.
• Provide a scientific basis for the food hygiene provisions of the Codex Alimentarius that
relate to objectionable matter.
6. The terms objectionable matter, foreign matter, foreign object and extraneous matter are
often used interchangeably. The GPFH defines contaminant as “any biological or chemical agent,
foreign matter, or other substances not intentionally added to a food which may compromise food
safety or suitability. For purpose of this document, objectionable matter is included in this
definition as “foreign matter not intentionally added to a food that may compromise its safety”.
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Foreign matter, foreign objects and extraneous matter, in the context of this document, are
broader terms which include objectionable matter but which also include matter that poses no
hazard to health such as aesthetic defects.
7. The design of the proposed guidelines is based on scientific principles whose validity is
recognized by the international community of public health scientists (see Annex 2). The
guidelines are designed to be flexible in that they may be applied to objectionable matter in food as
well as to potentially hazardous conditions, such as exposed glass light bulbs (potential physical
hazard) or rodent infestations (potential contributing factor to microbiological hazards). This
flexibility is necessary in order to interface with HACCP systems and other food safety systems.
• Section 2: Statement of the scope of the guidelines, with limitations that exclude
quantitative acceptance levels and aesthetic defects.
RECOMMENDATION
OUTLINE
TABLE OF CONTENTS
1. Introduction
2. Scope
3. Definitions of Terms
4. Procedural Guidance for Categorizing Objectionable Matter as Hazardous or Non-hazardous
4.1 Category 1: Physical Hazards from foreign objects
4.2 Category 2: Allergen Hazards from Food-Infesting Pests
4.3 Category 3: Vectors of Microbiological Hazards
4.4 Non-hazardous Extraneous Matter
5. Technical Guidance for Evaluating Hazards
5.1 Evaluation of Physical Hazards from Foreign Objects (Category 1)
5.2 Evaluation of Allergen Hazards from Food-Infesting Pests (Category 2)
5.3 Evaluation of Vectors of Microbial Hazards (Category 3)
5.3.1 Disease-Carrying Pests
5.3.2 Vector Activity
6. HACCP Hazards and Controls Guide
6.1 Control of Operation
6.1.1 Physical Hazards (Category 1)
6.1.2 Allergen Hazards (Category 2)
6.1.3 Vectors of Microbial Hazards (Category 3)
6.2 Decision Trees
6.2.1 Evaluating Hazards Associated with Objectionable Matter in Food
6.2.2 Evaluating Vectors as Contributing Factors to Microbial Hazards
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ILLUSTRATIVE EXAMPLES OF SECTION CONTENT
Example 1:
- The object is not a normal constituent that a consumer would expect to find
in the product (e.g., fish bones in whole fish).
Example 2:
5. Evaluation Guidelines
Foreign objects can cause injury to the consumer. Likely sources include raw
materials, processing machinery with parts that can break loose, worn equipment,
poor facility maintenance and personal items that employees may bring into the
processing facility. Preventive measures can include in-line detectors, inspection of
incoming raw materials, good manufacturing practices [other examples may be
inserted].
Bone (sliver/chip) Trauma Processing (e.g., hard/sharp bone pieces separated from flesh)
Is a contaminant found?
NO
No action is indicated
YES
YES
NO
This evaluation guideline
YES does not apply
Allergens. Recent studies in Asia, Europe and North America report life-threatening allergic
reactions due to the consumption of food contaminated with allergenic mites (2). The ingestion of
small numbers of mites in a food may induce IgE-mediated systemic allergic reactions, including
anaphylaxis, in sensitized individuals (3). Mite allergens are not denatured by normal cooking or
by freezing. The allergenic mites involved in these incidents are all food-contaminating species
that thrive under insanitary conditions (4). Other food-contaminating pests, such as cockroaches,
are emerging as significant causes of allergy illness (5). Although there is no dose/response
database for ingesting allergenic mites, the literature contains ample dose/response data for contact
and inhalant exposure to the same mite species that cause ingestive allergy illness (6,7,8).
Disease-Carrying Pests. Flies, cockroaches, birds and rodents are natural reservoirs and mechanical
vectors of foodborne pathogens (9,10,11,12). Recent findings implicate flies as potential vectors
for E. coli O157:H7 in beef or fruit products (13, 14, 15) and Salmonella Enteritidis in eggs (16).
Scientific reports also implicate flies as reservoirs and vectors of enterohemorrhagic E. coli
O157:H7 (EHEC-O157). These include epidemiological studies of the role of flies as vectors and
reservoirs of EHEC-O157 in Obihiro City and Saga Prefecture, Japan, both sites of recent outbreaks
of EHEC-O157. In the latter case, flies were found to harbor and proliferate EHEC-O157 (17,18).
The DNA pattern and vero-toxin were identical in the EHEC-O157 isolated from both patients and
flies. Exclusion of flies from exposed food and utensils halted the Saga outbreak even though the
excluded flies continued to test positive for EHEC-O157. Databases relating to the disease-carrying
capabilities of these pests include:
Epidemiological case control studies of risk factors for failures to exclude pests from food.
Vector control studies that report statistically significant positive correlations between the
suppression of pest populations and the reduction of disease.
Studies of the pest behaviors that are conducive to the transmission of pathogens to food.
Ecological studies that report the prevalence of pathogens in wild populations of a pest species.
Additional databases may include: studies on evaluating the danger from disease-carrying pests
(19); government criteria for evaluating disease-carrying pests (20); World Health Organization
manuals (21) and guidelines;1 and published questionnaire surveys that reveal tolerance attitudes of
the average consumer toward these pests (22).
1
W HO/V BC/86.937
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