[mst]

Finding a known toxin in one cartridge out of eighteen could be a single manufacturing error, but does indeed strike me as a potential problem.

The remaining statements give no statement of quantities or the likely effects ... so could indeed be a serious problem, or no more of a risk than background radiation.

Please consider the possibility that my refusal to take -your- claims at face value indicates a refusal to do so with anybody's claims rather than a desire to only accept evidence from one side of an argument.

> Are they safe though?

Safety can't be treated as an absolute; I know somebody who's substantially allergic to peanuts or the dust thereof, and as such could easily have a very bad reaction simply from somebody eating a bag of peanuts next to them. This is not to my knowledge commonly raised as an argument to make peanuts illegal - but seems equivalent to your "particularly susceptible to tobacco" point, unless I'm missing something.

> I have no idea

Neither do I, but I regard this as a reason not to immediately draw any specific conclusion rather than to consider anybody who makes a particular guess to be "falling for" anything.