MONTPELIER >> The Vermont House passed a bill calling for a saliva test to be used to check drivers for the presence of marijuana and other drugs — after a state-retained lab warned the test could not be used to measure impairment behind the wheel, documents show.

A bill approved by the House on April 20 would allow police to ask for a sample of a driver's saliva, and to use any trace of impairing drugs it showed as evidence of illegal impairment behind the wheel.

When marijuana and alcohol are combined, the House legislation said a driver would be deemed intoxicated if he or she had a combined blood-alcohol content of 0.05 percent and a level of marijuana's active ingredient in the body of 1.5 nanograms per milliliter of blood., a tiny amount.

Passage of the bill, which emerged from the House Transportation Committee, came after the panel was provided copies of a report by Pennsylvania laboratory that tested 58 Vermont saliva samples under a study commissioned by the state Department of Public Safety.

In its report the Center for Forensic Science Research and Education said this: "A limitation of OF (oral fluid) is that drug concentrations cannot be related to a specific degree of impairment in the driver."

A driver is assumed to be drunk behind the wheel when a breath test shows blood-alcohol content of 0.08 percent or higher. That's called a "per se" limit, meaning that, in itself, it proves intoxication under Vermont law.


What has bedeviled lawmakers considering marijuana legalization is that there is no scientifically agreed-upon per se level for pot or other drugs in which it's agreed that a certain amount in the blood stream means a person is too impaired to drive.

The Transportation Committee's version of the bill said a person would be deemed intoxicated with a BAC of 0.05 in combination with any detectible amount of marijuana in the blood; that was amended on the floor with the insertion of the 1.5 nanograms per milliliter pot standard.

A key backer of the saliva tests, Rep. David Potter, D-Clarendon, said the results would be added to other evidence in court, including an officer's testimony, and likely that of a police drug recognition expert.

The 1.5 nanogram level and the use of the saliva test have critics like Defender General Matt Valerio and Allen Gilbert, executive director of the American Civil Liberties Union's Vermont chapter, spitting mad, due to the lack of firm science linking blood levels with impairment.

"It's 'Reefer Madness' II," Valerio said, referring to a 1930s anti-pot film. Anyone who smokes marijuana at all would effectively face a new BAC limit for drunken driving of 0.05, he argued.

As of last year, 14 states allowed police to use saliva tests to check for drugs.

Two key senators, Transportation Committee Chairman Dick Mazza and Judiciary Committee Chairman Dick Sears, both Democrats, said recently they did not believe there was enough time left in the current session in Vermont for the saliva test provisions to clear the Senate.

But Gilbert predicted the issue will be back next year, because there are two companies actively marketing testing devices to law enforcement.

So far, he, too, said they aren't close to equating the presence of a specific drug with impairment.

And authorities had better get it right, Gilbert argued, because in a rural state like Vermont, the loss of driving privileges that often accompanies an impaired driving conviction often means an inability to get to work, school, houses of worship, political events, even grocery shopping.

"Taking away somebody's ability to drive in this state is a real handicap to them, and if you're going to do it you want to make sure you are doing it correctly and fairly," he said.