You've probably all learned about genetics in school; and probably
tasted those small strips of PTC-paper that tasted bitter, or nothing
at all. But did you ever read up on PTC?

This is the MSDS for phenylthiocarbamide (phenylthiourea); it is twice
as poisonous as Sodium Cyanide in rats:
http://physchem.ox.ac.uk/MSDS/PH/phenylthiourea.html
http://physchem.ox.ac.uk/MSDS/SO/sodium_cyanide.html

Then to the question: Can someone find a recipe for PTC-paper, or find
the concentration of PTC on regular PTC-paper? Are there any MSDS oout
there specificallly for PTC-paper?

Thanks:-)

Well, looking at that page, the LD50 is 3mg/kg.  I'm a little off on
my average weights, but say a kid was around 100 pounds, or 45 kgs. 
That means it would take 135 mg of phenylthiourea to have a 50% chance
of killing them.  I'm sure you're not going to get that much by
touching your tongue to the paper for a second.

Plus, MSDS sheets have a habit of being a little overcautious; ever
read the one for salt (sodium chloride)?  They're mostly CYA for the
manufacturers so when some retard decides to stuff his face with lye
they can't get sued.

Oh, and on further inspection, PTC paper is made of
phenylthiocarbamide, not phenylthiourea, so it's a moot point.

*Sigh* And on further inspection, they're the same thing.  

Guess I should read your post more carefully next time ;)

Anyhow, probably not toxic or they wouldn't use it in studies.

Your last comment made me use a lot of credibility in you
trek...that's like saying...

lead's probably not toxic, or they wouldn't use it in paint/gasoline
asbestos is probably not harmful, or they wouldn't use it as insulation
cigarettes probable aren't harmful, or they wouldn't be selling them everywhere...

about ptc, i have no clue.  but I do remember taking the test, and
well, I'm not dead yet.

According to this website, a person would have to taste about 5000
test strips to hit the LD50.

http://www.sciencelab.com/laboratory-equipment/PTC_Paper.html

"Ability to taste PTC is a hereditary trait. (The taste of PTC varies
with the individual.) PTC paper which is often used when discussing
heredity in biology classes, is paper soaked with phenol thiocarbamide
(PTC). The LD50 for PTC is 3.4 mg/kg. Such a low LD50 reveals that PTC
is a very hazardous substance. The solution to make the taste test
paper contains approximately 500 mg of PTC per liter of water. Through
some very crude arithmetic, we calculate that each strip of PTC paper
would contain approximately 0.3 mg of PTC. We estimate that a student
weighing about 50 kg would have to lick (That is how the test is
performed) and ingest about 5002 x 1/4" strips of PTC paper to reach
the LD50. You will have to judge if you wish to use this taste test
paper."