We sent people to DOT regulated sites. The drug test would specifically screen for that drug along with others.
Proof of that drug only would not result in failure.
The test gives more complex results than overall pass/fail, although p/f is usually the only information shared unless specifically requested in advance.
We did not have people operating heavy machinery, but they would be walking around in areas where heavy machinery was routinely in operation.
Not wanting to argue with the safety premise, but the usual “pee” test gives results for past 30 days use. Other than being an indicator of past usage, specific to recreational drugs like pot, 30 days prior use does not affect performance and safety. This point is not about harder, more dibilitating and longer effecting drugs.
In Australia, the standard drug test is a mouth swab which shows drug use for previous few days not 30 days, which is more appropriate for workplace safety.
Like many other areas of how life has evolved in America, many things have evolved from over-reaction to a problem. We need to return to more common sense approaches in many areas not to mention political. The Austrialian “swab” drug test seems more common sensicle.