Difluoroethane

[Mr Skeptic]

Regarding it being a necessary trace element. I did not know that.

 

I'm not sure how necessary it really is. I don't know if it does anything other than strengthen bones and teeth. It is really hard to not get the minimum requirement (other than teeth) so it doesn't get much attention or matter much.

 

Elemental fluorine is F-F (as in F2). Fluoride is a salt, F- (such as in NaF or KF). NaF is the stuff generally added the city water supply and toothpaste. The fluoride anion is what strengthens teeth. Is the fluoride anion the one considered a "necessary trace element" (although it is not elemental fluorine)?

 

I think it is just the fluorine that matters. I don't really know.

 

I've wondered what those "whitening" factors are but haven't taken the time to look them up. What are they, Mr Skep?

 

As Darkblade48 said, it's bleach for teeth. Not good.

 

I don't agree with Darkblade48's idea that we should put fluoride in our drinking water just because it won't kill us (immediately). So we'd have to drink 100 times our weight in water to get an LD50 dose. How fast if fluorine removed from the body, though? Obviously, you wouldn't want to get even near a lethal dose, and there are bad effects if you get too much.

 

Ever hear of a case of fluorine deprivation (with the exception of teeth)? There's quite a few cases of overdose.

[Darkblade48]

As I mentioned previously, the 5000 litre consumption of water is assuming a LD50 of 52 mg/kg (not the higher 75 mg/kg in humans). Also, that's assuming that the water has a fluoride concentration of 0.67 mg/L and not 0.12 mg/L. If we take these new calculations into account, the LD50 would be 4875 mg, and at a fluoride concentration of 0.12 mg/L, we would have to consume 40 625 L of water in order to reach the LD50.

 

Obviously, at such a ridiculous number, we'd die of osmotic shock long before reaching toxic doses of fluorine. According to Wikipedia (unfortunately, it's 6:49 am local time, and I don't want to bother looking up a better source at this hour), fluoride compounds are excreted through the urine, with a half life on the order of hours. Needless to say, fluoride compounds just don't have the "staying power" as some other more toxic elements (such as cadmium).

 

Of course, fluorosis can be a potential problem, but this would only be caused by an excessive intake of fluoride compounds during tooth development. By excessive, I take this to mean much greater than the concentrations found in fluorinated water.

 

Regarding your comment regarding attempting to stay 10^-12 below the LD50 (I assume this is what you meant by wanting to stay "x below E12 the LD50"), DrDNA; I think this is absurdly impossible. For example, the LCLO for ozone (inhalation, humans) was 50 ppm over a period of 30 minutes. It would be impossible to achieve a concentration of 5.0 * 10^-11 ppm of ozone in any given urban area (or rural area, for that matter)

[DrDNA]

Regarding your comment regarding attempting to stay 10^-12 below the LD50 (I assume this is what you meant by wanting to stay "x below E12 the LD50"), DrDNA; I think this is absurdly impossible. For example, the LCLO for ozone (inhalation, humans) was 50 ppm over a period of 30 minutes. It would be impossible to achieve a concentration of 5.0 * 10^-11 ppm of ozone in any given urban area (or rural area, for that matter)

 

 

E12 was not meant to be taken literally, but my point still stands.

LD50 is not a good way to judge what how much of a toxic chemical to put in a person's system.

 

Of course you are free to drink all the fluoride water and use fluoride containing dental products you want. On the other hand, I do not appreciate the water company putting it in my drinking water and I will continue to avoid it.