Portable drug test a new addition at New Year's DUI checkpoints

[jmowreader]

4. Yes, but it takes a blood draw to do it

THC has three chemicals associated with it.

The first is THC-COOH (THC-carboxylic acid). This is the form you find it in the plant, and it's the second-order metabolite. This is not psychoactive, which explains why you don't stay high for a month after smoking weed and also explains why very few people eat raw marijuana salads.

Heating THC-COOH produces THC, whose effects are well known. This is so short-lived it never makes it to your kidneys.

THC first metabolite is 11-OH-THC. This is also psychoactive but it seems to be what actually causes the munchies. This chemical's life in the body is a matter of hours.

So! Test for 11-OH-THC and you can tell whether a driver has smoked weed recently enough to be suffering the effects of it.