Originally Posted by aka123

US has less employee protection than for example around here, but let me quote myself.

"Usually it is considered that employers have jurisdiction towards their workers only when they are at work, especially when the personal life things have nothing to do with the job."

So, employer can forbid for example drinking alcohol in job, but unless your work is about being some absolutist role model, then it has no saying that do you drink during your freetime or not. Same for everything else legal. And even if it is illegal; like walking against red light, it is not guaranteed to be sufficient reason to fire someone, assuming that you need some reason, other than "I feel so".

Alcohol of course leaves body quite soon, and I don't think that there is yet guidelines for having traces of cannabis at work. But there surely will be in the future.