They’re testing for coke, pot, etc. just as previously mentioned.
If you smoke :shaggy: and they do a lipid test, and you’ve smoked within the last 30 days, you’re probably SOL. Piss test, however, they will look for “tainting” agents (bleach, baking soda, ph adjusters, goldenseal, etc.) and if they’re detected, you’re assumed to be hiding something.
If they do a root-follicle test and you’ve ever done coke in the last 7-ish years, they can find it there.
Good luck.
Forgot that one, good catch!