Marijuana smokers – those doing so both legally and illegally –  should think twice before getting behind the wheel under the terms of a bill at the Legislature that is poised to become law.

The measure, by Sen. Steve King, R-Grand Junction, would create a new standard for the THC blood content of drivers arrested for driving under the influence. THC, short for tetrahydrocannabinol, is the key ingredient in marijuana.

The bill was resurrected after being killed by the Senate a year ago, and was only approved  Tuesday by a single vote, from Centennial Republican Nancy Spence, who switched sides.

Under the terms of the bill, any driver with five nanograms of THC in their bloodstream would be guilty of DUI. Currently, there is no blood limit standard, and anyone charged with driving under the influence of marijuana must be convicted by a jury.

Opponents, such as Denver Democrat Pat Steadman, argued that five nanograms is too subjective a standard to convict everyone who has that much THC in their blood, especially since there are 80,000 Coloradans who legally use medical marijuana.

Many El Paso County legislators, Democrat and Republican alike, sided with King, saying the measure is a public safety issue.

 “I don’t think there’s any evidence that having THC in your blood helps you drive,” said Senate Majority Leader John Morse, D-Colorado Springs. “Once there’s science to prove that people are competent to drive, I’ll support it. Until then, there needs to be a limit.”

 There are already alcohol standards for driving under the influence, pointed out Sen. Kevin Grantham, R-Canon City, who represents a large chunk of El Paso County. Grantham called the bill “a step in the right direction.”

 “I wouldn’t be surprised if we see adjustments in the future, as science evolves, but for now, five nanograms is a good place to start,” Grantham said.

Even lawmakers in the House, who have not yet seen the bill, said they’re inclined to support some numeric limit of THC for drivers.

“We need to have a presumptive level, just as we have for alcohol,” said Rep. Mark Barker, R-Colorado Springs. “And by setting a certain level, you’re actually giving protection to those who use medical marijuana, by making clear what the legal level is.”

Barker and Morse are both former police officers.

Rep. Pete Lee, D-Colorado Springs, sided with Steadman in opposing the bill, and said one of his top concerns is that medical marijuana patients aren’t unjustly convicted of DUIs.

The bill must be approved one last time by the Senate before heading to the House, where it likely would be passed.

Photo by THE ASSOCIATED PRESS FILE

Jeff Chiu