Colorado House passes bill that sets blood standard for driving under influence of marijuana

A long-debated Colorado bill setting a marijuana limit for drivers faces an uncertain fate in the state Senate after it was passed Tuesday in the House.

The bill setting a blood standard for THC, the psychoactive ingredient in marijuana, will be debated later in the day in the Senate, where a Republican senator who changed her vote to support the measure earlier this year was absent. A vote was likely Wednesday.

The missing vote could mean another defeat for the proposal to make Colorado the third state with a blood-level limit for marijuana, much as the nation has a blood-alcohol limit of .08.

<snip>

Marijuana activists are fighting the proposal because they say blood THC tests are an unfair gauge of impairment. Because the body processes marijuana differently than alcohol, they say, a clear blood limit could endanger marijuana patients who aren't impaired.

http://www.startribune.com/nation/151567215.html