Note that non-toxic does not mean edible, as the FDA recently clarified due to many people being severely poisoned from eating cakes decorated with luster dust meant for crafting.
TYPE OF TEST:
LD50 - Lethal dose, 50 percent kill
ROUTE OF EXPOSURE:
Oral
SPECIES OBSERVED:
Rodent - rat
DOSE/DURATION:
584 mg/kg
DOSE/DURATION:
508 mg/kg
Non-toxic definitely means that common exposure to the product shouldn't pose serious risks to one's health. In other words, licking a Nintendo Switch cartridge should not result in a dose of denatonium anywhere near high enough to cause any deleterious health effects. Drinking entire bottles of the stuff probably will.
This luster dust apparently contains lead, how these manufacturers managed to conclude that it is non-toxic is beyond me.
Apparently one of the "luster dusts" was 25% lead, and another was pure copper dust, which is also pretty toxic if ingested. Lead sulfide (galena) is 86% lead, shiny when in large crystals and probably low enough toxicity that you could label it as "nontoxic". https://www.mindat.org/mesg-361788.html says the oral LD50 of galena in guinea pigs is 10000 mg/kg, which is about three or four times less acutely toxic than table salt. But table salt doesn't accumulate in your bones and brain over time, so seasoning all your food with galena would still be worse for you, even if you didn't chip your teeth.
I thought lead metal was maybe also inert enough to prevent lead poisoning from metal ingestion—just as you can drink substantial quantities of metallic mercury with no ill effects—but that turns out to be wrong. https://en.wikipedia.org/wiki/Lead#Toxicity says, "Most ingested lead is absorbed into the bloodstream," and https://en.wikipedia.org/wiki/Lead_poisoning#Lead-containing... says, "Ingestion of metallic lead, such as small lead fishing lures, increases blood lead levels and can be fatal.[126][127][128][129]"
Yeah none of those luster dust formulations should qualify as "non-toxic" in my book.
Copper and lead salts are not only acutely and chronically toxic to humans, they can be disastrous to aquatic life if they get into water ways. Cu powder gets a solid GHS09: dead fish. Suprisingly does not get the the Health Hazard GHS8. PbS gets GHS7/8/9, right proper toxic.
Maybe they mean it's not acutely toxic? Usually either short or long term toxicity is more than sufficient to call something "toxic".
Yeah, I don't know. Maybe it's just a negligent error?
I'm not going to try eating some copper powder to find out, but I'd expect stomach acid to yield a substantial amount of highly soluble copper chloride. I guess I could try vomiting on some copper powder. But I won't.
Kinda makes you wonder what the relative toxicity of a Switch cartridge is. Some labcoat at Nintendo probably ran the number for this one on the weekend.
If anyone else is wondering, the only somewhat concise explanation I found was this[0]:
> Non-toxic is essentially a placebo term and unlike food-safe or food-grade products, has little to no government regulation in terms of its accuracy. [...]
> What non-toxic means is that the product contains no ingredients that have been linked to toxic responses in humans. Toxic responses are things like hormone disruption, poisoning, or cancer.
One of the basic principles of toxicology is "the dose makes the poison".
From an OSHA perspective, "toxic" means (amongst other things) a mean-lethal-dose (LD50) of up to 500 mg per kilogram of bodyweight when ingested orally in lab rats.
There's all kind of stuff that doesn't meet the standard of toxic that you still wouldn't want to eat.
https://www.cdc.gov/mmwr/volumes/70/wr/mm7043a2.htm
You would think that if something says non-toxic, licking it shouldn't kill you, but apparently not.