[DougN7]

I really don’t know, but could there be 100 other substances as dangerous and easy to mix/administer as cyanide? There must be some cut off since you can’t test for everything. I’d be interested to know what that test matrix/decision document looks like.

[laser_eagle]

Cyanide is found as an impurity from both natural sources and as a byproduct during the manufacturing process, a lot like lead. So it's common enough to warrant the expense of testing