When I was still with NASA and about to be put on an Army Core of Engineer's contract, they had me start the process for Secret Security clearance. The preliminary drug test was unmonitored automatically submitted to lab, and I used Quick Fix on it, and passed.

I ended up never finishing the clearance, due to switching to another job, which on a side note, was probably the stupidest thing I could have done. Working in a town with NASA and a military base, and I thought it wasnt worth staying for a secret security clearance. Sometimes, Im a dumbass.

But to answer your question, from personal experience, yes, it is safe. But I would wait for FBR to answer, he would be able to give you a certain answer, instead of one just from one personal experience.