[Eripiomundus]

I found a forum post saying that Ca²⁺ would bind F^- in a biologically inactive form. They didn't mention the compound name, but it would have to be CaF₂, which is either detrimental or harmless when ingested depending on where you look.

So, to be safe, I looked for another way to get rid of fluoride ions from drinking water, and was told that Borax (disodium tetraborate decahydrate, Na₂B₄O₇.10H₂O) would do the trick. I'm not far enough along in chemistry to figure out how this chemical would react with F^- though (just starting out). Would someone please help me?

I'm guessing you'd end up with NaF and the borate would bond with something else in water? Some other contaminant maybe? Also, can someone please tell be whether the products of this reaction (if any) would react with the HCl in the stomach, and what the products would be?

[Borek]

If anything, after precipitation of fluoride, you want to filter the solids out. Or at least wait till they settle down.

[Hunter2]

Calcium or better Barium give precipitate of the flouride. Borax do nothing. Why asked what HCl do in stomach. Large amount of flourides are poison. Barium as well. As already mentioned precipitate you have to filter.

[Eripiomundus]

Of course! Great answer.

I was asking about the HCl because stomach acid is HCl, and I wanted to know whether the potential products of F^- and borax would react with the HCl to produce something harmful upon ingestion.

Thanks for the responses.

[Hunter2]

If you have soluble fluorides HCl creates hydrogen fluoride, what is very poison. Borax itself is some poison no need for HCl.

[Eripiomundus]

Fluoride compounds of different types are added to civilian water supplies, but they all ionise into F^- in aqueous solution. So, if what you say is true, and fluoride reacts with HCl to produce hydrogen fluoride, why is it being put in our water supply? Pretty scary.

With the Borax I'm getting mixed information. According to the Material Safety Data Sheet it has a lower lethal dose (for 50% of subjects - LD50) than table salt. They cite studies that link reproductive defects in mice, but the amounts used to achieve these results are enormous. Probably if you took any substance to the same degree of excess it would lead to at least as serious a set of side effects.

On the other hand there are a few anecdotal reports out there, and not one of them is disparaging. 

[billnotgatez]

@Eripiomundus
What is the ppm in civilian water supplies of fluoride compounds?
What is the ppm in toothpaste of fluoride compounds?

[Eripiomundus]

1 part per million in the water. 1000 ppm in toothpaste (average).

So H₂O molecular weight = (2+16 = 18) grams per mol.
18/6.02*10²³ = 2.99*10^-23 grams per molecule.
1,000,000 * 2.99*10^-23 = 2.99*(10^-17) grams of water per Fluoride ion.
The average man needs around 2800mL water per day, and a mL of pure water weighs 1g.
2800/(2.99*10^-17) = 9.36*10¹⁹ fluoride ions consumed per day.
Fluoride ion mass = 19, so:
19/(6.02*10²³)*9.36*10¹⁹ = 2.954*10^-3 grams of Fluoride per day. (can someone check my calculations please - I'm pretty new to chemistry).

2.9mg doesn't seem like much I guess. The recommended dosage is listed here http://www.nlm.nih.gov/medlineplus/ency/article/002420.htm as being 3-4mg a day for an adult human.

I've read that fluorides bioaccumulate, mainly due to the F ion's proclivity for binding to the calcium in bones. Also, it might be worth noting that in countries where drinking water is fluoridated there is a feedback mechanism at play. Not only do you get it in your water, you get it through the plants that are watered with it, the food products using water in processing, the beverages that use water as an additive (like Coke and reconstituted orange juice).

There are many, many, sources that claim fluoride is a poison - it used to be used in rat poison, for instance, and rats are used in medical research because their systems often behave similarly to ours. The Nazis apparently used it in their concentration camps as a means of making people more compliant and less likely to cause trouble. It's hard to know whose information to trust really.

[billnotgatez]

Some reading to help understand the subject

http://en.wikipedia.org/wiki/Water_fluoridation

From the WIKI article

In 1999 the U.S. Centers for Disease Control and Prevention listed water fluoridation as one of the ten great public health achievements of the 20th century;

[Eripiomundus]

No offence, but I don't think Wikipedia is a reliable enough source to trust your health to.

[billnotgatez]

I don't think Wikipedia is a reliable enough source to trust your health to

I suppose one could have that opinion

But the
111 Citations at the end are of note

For instance

 CDC. Ten great public health achievements—United States, 1900–1999. MMWR Morb Mortal Wkly Rep. 1999;48(12):241–3. PMID 10220250. Reprinted in: JAMA. 1999;281(16):1481. doi:10.1001/jama.281.16.1481. PMID 10227303.

I go to WIKI for the summary
I go to the citations for the facts

Additionally, It is my impression that members of organizations like American Chemistry Society have committed to supporting the integrity of WIKI.
see
http://www.chemicalforums.com/index.php?topic=32165.0

So no offense taken

By the way, I think you will find commercially available systems to remove fluoridation from your water, if you really think there is a need.

[Eripiomundus]

I do the same, I have to admit (look up the wikipage and go from there).

You're right about the commercial methods. There are filters, but they're expensive, and I thought making Ca⁺ ions from egg shells and vinegar would be a cheap way to go about it for the time being.

Thanks for the comments.

[Borek]

There are many, many, sources that claim fluoride is a poison

No contradiction here. It is a dose that makes a poison. It is quite common that substances that are necessary in small amounts are dangerous in large amounts.

[Eripiomundus]

Sorry. Just to clarify, many of the sources claim it to be a poison even in small doses, being bio-accumulative. It's frustratingly hard to get a clear picture. I've never heard of anyone, ever, being diagnosed with a fluoride deficiency. Phosphate deficiency yes, iron, potassium, calcium, magnesium, selenium, zinc and so on... all yes. But no fluorine deficiency. Studies indicate drinking it doesn't even help your teeth. Only topical administration protects dental enamel, and only partially. A recent Harvard university study linked it to lower IQs. Yet any government source will tell you A) it is good for your teeth, and B) is necessary for your health.

I've been looking into nutrition lately, and it's a minefield of contradictory information, so I made the decision to assume the conditions in which man evolved are the same that promote good health. When we were cave men we didn't need fluoridated water. If we needed it at all we got fluorides from our diet. As for teeth - look at the research by Weston A Price showing that people still living a lifestyle as close to the hunter/gatherer one as possible have immaculate teeth. I just can't help asking "why fluoridate? What is the point of it?" There seems no clear benefit in any way, and a lot of concern over the dangers. Would so many people really get so concerned over nothing?

[Borek]

Would so many people really get so concerned over nothing?

Sadly, the answer is - yes (which is not intended to mean I am for or against fluoridation). Think anti vaccers.