Talk:Fluoride

Toxicity of fluoridated water

Greenwood and Earnshaw, p. 792, provides a very succinct discussion of the toxicity of fluoride in drinking water. If anyone is going to alter the current article text on fluoridation, they might like to consider the main points raised in this authoritative textbook on inorganic chemistry.

In a nutshell:

• SnF₂ is used in toothpastes

• low concentrations of F⁻ in drinking water protect against dental caries (originally investigated in the 1930s by H. T. Dean et al (some literature refs here, at the bottom)

• below 1 ppm F⁻, there are no adverse effects, short term or long term

• several countries fluoridate their water, using NaF or H₂SiF₂

• 2-3 ppm F⁻ can turn teeth brown

• at 50 ppm F⁻ harmful toxicity occurs

• 150 mg of NaF causes poisoning, but this can be easily reversed with appropriate treatment

• fluoridation has been controversial for a long time - however, much of the controversy is not about whether fluoride is toxic but whether people have a right to access untreated water if they want to

This seems to be a balanced coverage of the issue, while giving due weight to the chemistry and not dwelling too long on controversy. The uncontroversial points are just as important as the controversial ones, but controversy always gets a lot of attention.

Fluorides aren't nearly as toxic as many other chemical species, but they are common in everyday experience and commonly encountered forms do have some degree of toxicity, so that is worth noting. I am ambivalent about the fluoridation controversy (I'm much more likely to die of something else!) but it's just interesting to see toxicity discussed and compared - I like reading about the toxicity of compounds, it's just one more aspect of their behaviour, i.e. how they react with people:

:| + mF⁻ → :D

:) + nF⁻ → :(

(m = just the right amount, n = too much)

Ben (talk) 19:41, 16 May 2008 (UTC)

The above is not a balanced presentation of the toxicology of Fluorine/Fluoride. Please see Christopher Bryson's work on the topic of Fluoride toxicity. His book is easily the most cohesive and exhaustive treatment on Fluoride. He has utilized actual research, original documentation and simple logic to show exactly how toxic and harmful fluoride is to humans. —Preceding unsigned comment added by 70.49.252.94 (talk) 06:43, 16 April 2009 (UTC)

The title of Christopher Bryson's book is "the fluoride deception". —Preceding unsigned comment added by 70.49.252.94 (talk) 06:46, 16 April 2009 (UTC)

I think the very title of that book shows it to be biased!

Ben (talk) 14:27, 3 October 2009 (UTC)

Silicofluoric acid

The article is new and might get into this fluoridation controversy!--Stone (talk) 16:05, 28 June 2008 (UTC)

Sorry! Made a redirect because we have an article already! --Stone (talk) 16:12, 28 June 2008 (UTC)

Acidity/Alkanity

As I understand it, hydrogen fluoride is a weak acid, therefore the fluoride anion is a relatively strong base. Shouldn't its alkanity appear in the article? —Preceding unsigned comment added by 99.238.142.12 (talk) 16:16, 17 August 2008 (UTC)

Hydrofluoric acid (HF) is a weak acid in aquaeous solution (at 25^oC, K = 7.2 x 10^-5 according to Basic Inorganic Chemistry 3rd Edition p. 233), but liquid HF is one of the strongest known acid. I would also suggest to use the word basicity over alkalinity. Mandor (talk) 15:36, 16 October 2008 (UTC)

That is considering to different definitions of "strong", not differences in HF. Rmhermen (talk) 22:09, 16 October 2008 (UTC)

Already covered in Hydrogen fluoride, Fluorine and Hydrofluoric acid. It just need some data. Mandor (talk) 19:52, 20 October 2008 (UTC)

Some ideas

Under "Occurrence"

1) "Its closest chemical relative is hydroxide." Please add a reference and state what does it really mean. I know that they both have the same van der Waal radius, that is probably what the author meant ?

2) "The Si-F linkage is one of the strongest single bonds" Energy ? Compare to something else maybe, usually C-C.

According to Basic Inorganic Chemistry 3rd Edition the bond energy at 25^oC (in kJ mol^-1) is 368 for Si-O, 582 for Si-F and 356 for C-C. A quick look at the table reveals that this (Si-F single bond) is indeed very high if not the highest (???) Mandor (talk) 15:07, 16 October 2008 (UTC)

Under "Applications"

3) "It is principally used in the production of fluorocarbons ..." If my memory serves well, they use "magic acid" or SbF5 + HF. But I am not too sure about that. I will try to find a reference. Mandor (talk) 23:49, 15 October 2008 (UTC)

I was wrong ! According to Tetrahedron 59 (2003) 437–454, they use an appropriate fluorinating agent such as elemental fluorine, cobalt trifluoride or anhydrous hydrogen fluoride in an electrochemical cell. It is a really nice article on perfluorination of hydrocarbons. Mandor (talk) 00:49, 16 October 2008 (UTC)

All right it is getting late. This is already covered in "Perfluorocarbon". Mandor (talk) 01:12, 16 October 2008 (UTC)

Invisible water?

I have applied tags to the section Fluoride#Invisible_water. The assertions are not duly sourced; they are apparently reported with serious distortion from an unnamed Mythbusters episode. The gas may be dense, but that does not make it "invisible water". If the section is not amended within a few days, it ought to be deleted.

–_⊥^{¡ɐɔıʇǝo}Noetica!^T– 02:20, 17 February 2009 (UTC)

As micronutrient

There's no discussion of this issue that I can see, so I've downgraded this article to C-class, as this is an important topic/application (the rest of the applications are conveyed telegraphically as well). NAP has a free book (chapter) on this. I'll update the article from it over the weekend unless someone beats me to it. Also, it's not clear to me what should go in this article, as opposed to the article on the element itself, fluorine. Since this is a more general question, I've started a discussion at WT:CHEM. Xasodfuih (talk) 17:37, 4 March 2009 (UTC)

See fluorine deficiency, which is covered under biological role there. The NAP book is OK but 12 years old. Fluoride is no longer used for osteoporosis, and most sources don't think that ingesting fluoride prevents tooth decay (see Aoba 2002 and Pizzo 2007). NAP 1997 classifies as fluoride as a beneficial but not essential nutrient. II | (t - c) 07:00, 16 April 2009 (UTC)

regarding the content of this article: the general view among active editors is that Wikipedia should have articles on the main anions. The practice is asymmetric in the sense that WE doesn't have articles on the corresponding cations, probably for etymological reasons: "sodium" means both "Na" and "Na⁺"). Fluoride is so extremely controversial (myriad articles on various fluorine-related themes to satisfy the nutcases, staunch communist conspiracies, etc) that the fluoride articles are often a focal point for argumentation, so tread carefully and reference well to non-primary sources such as the NAS report.--Smokefoot (talk) 12:38, 16 April 2009 (UTC)

Both the articles I mentioned are reviews. 12 years is a long time in medical research. II | (t - c) 16:23, 16 April 2009 (UTC)

Nazis used fluoride to make people docile?

I have a friend who tells me the Nazis used to fluoride on prisoners to make them docile. All I can find about this is a few words purported to be from someone called Ian E. Stephenson and a few words purported to be from Charles Perkins. I was expecting to come to Wikipedia and be able to get the lowdown on this but found nothing. Am I wrong to expect to be able to find information either way on this kind of claim? I thought if there's any place it's Wikipedia. —Preceding unsigned comment added by 82.44.15.189 (talk) 20:30, 9 May 2009 (UTC)

It only gets into Wikipedia when someone discovers it's not there and finds a reliable source to support/refute it.:( I've seen this claim on lots of blogs and sites with a clear agenda, but no actual reputable historical evidence. DMacks (talk) 20:54, 9 May 2009 (UTC)

Toxicity section

I removed a couple of paragraphs in the toxicology section dealing with organoF compounds such as pyrolyzed Teflon and the nerve gas sarin. I am not trying to suppress this information, but it just does not see very relevant to an article on fluoride (F^-). I also added a section essentially verbatim from the safety section of the article on sodium fluoride.--Smokefoot (talk) 23:04, 21 February 2010 (UTC)

What is fluoride?

Fluoride is the element fluorine bonded with another element.

The following sites have information about this. http://education.jlab.org/itselemental/ele009.html http://www.fluoroseal.com/fluorine.html (Zxoxm (talk) 10:17, 11 December 2010 (UTC))

The textbooks are probably even more authoritative than any webstie because publishers have more quality control and are subject to academic review. I included your suggestion about fluorides are often compounds with bonds to F.--Smokefoot (talk) 15:40, 11 December 2010 (UTC)