re: Oil and Gas/Chemical plant drug testing

Here is what I know:
all drugs are undetectable in urine after 48 hours, exceptions are some Barbituartes, TCH, and PCP.

It's not a folicle test. It is a hair test. Folicle is below the skin.

Labs want at least 1.5 inches of hair from the head. If not long enough to present an approximate 90 usage window, then hair from other body areas is used.

Hair on your arm or leg has been there a long time. No one knows for sure. Therefore the window is certainly beyond the 90 days.

DISA forces you into rehab. This can be very expensive.
Some facilities don't care if DISA has allowed you to return, they simply have a one strike, zero tolerance rule and you are banned for life from all of their facilities.

THC is not going to be detectable in urine 21 days after your last hit. I always get arguments on this one.

Occasional THC use will not be a problem after 2 - 3 days. In other words, enjoy yourself friday, and pass on Monday morning.

Random frequency: Most industrial contractors have to test 10% of their crew monthly. Your number could come up every month because the pool doesn't exclude you if your were picked last month. Random means everyone has the same chance of being selected every time.

That is all.