Talk:Fluoride

I've just been searching for why toothpaste expires. Apparently, the FDA (in the US) regulates fluoride as an active ingredient, so an expiration date is required. Two years is the default. Several articles state that after two years, fluoride "breaks down". That doesn't fit with my understanding of how halide chemistry works. Is there a chemist in the house who can tell us what happens to fluoride ions in toothpaste as it ages (if not here, then in a toothpaste article with a link from here to there)? — Preceding unsigned comment added by Jeffryfisher (talk • contribs) 01:41, 10 October 2020 (UTC)Reply

Not a toothpaste expert, but a chemist here. You're right to be suspicious of fluoride ever degrading, I mean what is F^- to do? My guess is that the gelatinous goop phase-separates such that it ceases to ooze out in a chemically homogeneous format.--Smokefoot (talk) 02:28, 10 October 2020 (UTC)Reply

I remember hearing that early toothpastes used sodium fluoride but that this could slowly react with calcium minerals in the paste to form calcium fluoride, which is insoluble in water and thus ineffective for cavity prevention. Tin(II) fluoride lasts longer and sodium monofluorophosphate longer again. I'm afraid I don't have a source to back that up though. --Project Osprey (talk) 18:42, 10 October 2020 (UTC)Reply

I'd assume it has to do with

> However, upon prolonged contact with moisture, soluble fluoride salts will decompose to their respective hydroxides or oxides, as the hydrogen fluoride escapes. Fluoride is distinct in this regard among the halides. The identity of the solvent can have a dramatic effect on the equilibrium shifting it to the right-hand side, greatly increasing the rate of decomposition. JGHFunRun (talk) 04:16, 13 September 2022 (UTC)Reply

That is interesting... do you have a reference? --Project Osprey (talk) 09:21, 13 September 2022 (UTC)Reply

https://en.wikipedia.org/wiki/Fluoride#Basicity

Is where I got the statement from. That said it doesn't appear to have a proper citation JGHFunRun (talk) 20:01, 24 September 2022 (UTC)Reply

I was just wondering if you could touch on the amount of fluoride in tobacco, explain how much fluoride a heavy smoker would get each day, and whether that would have any effect on their cavity rate. Jane and Joe Public (talk) 02:35, 21 January 2022 (UTC)Reply

Didn't anyone ever tell H. Trendley Dean, the father of fluoridation, that correlation is not causation? He had no fluoride-deficiency lab work done on the population to support his pseudoscience. All he measured was the fluoride levels in water. Not the fluoride levels in people. Jane and Joe Public (talk) 03:50, 22 January 2022 (UTC)Reply

It doesn't discuss any potential harms caused by fluoride or by water fluoridation. It is disgraceful. Jane Joe Public (talk) 15:14, 23 January 2022 (UTC)Reply

This article here is only about the chemistry. We have several whole other articles about the public-health/policy and related aspects that are linked from it. DMacks (talk) 15:18, 23 January 2022 (UTC)Reply