Question: “Why did the people who came up with Initiative 502 (the marijuana legalization initiative) set the threshold for drugged driving so low?
They want it to be 5 nanograms per milliliter of THC for a DUI while the federal standard for pilots and truck drivers is 50 nanograms per milliliter.
This law will result in every medical marijuana user never being able to drive again for fear of a DUI. -- Heidi, Tacoma
Answer: You’re confusing standards for two different components in marijuana.
Federal agencies, probation officers and most drug-free businesses test for carboxyl-THC – an inactive metabolite in marijuana that stays in your system for days or weeks.
That indicates whether somebody has been using marijuana sometime in the recent past, but it doesn’t tell you if somebody is too stoned to drive.
What I-502 would do is measure the active, intoxicating component of marijuana, which spikes rapidly after use and then drops quickly back down.
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