Yesterday, a marijuana activist said that a controversial THC driving bill, a version of which failed each of the past two years, appeared to be a lock for passage -- and he was right. The measure breezed through by a 24-11 vote despite what critics describe as an almost total lack of scientific evidence to suggest that the intoxication standard is accurate for all people. Indeed, once the law is signed, Westword marijuana critic William Breathes likely will not be able to drive without breaking the law. Details below.

As we've reported, driving while stoned is currently illegal under Colorado law. But unlike in the case of alcohol, there's no number at which a marijuana-using driver is considered to be officially impaired -- and cannabis activists see that as a good thing, since the science on the subject is infinitely less certain than it is in the case of booze. Nonetheless, the medical marijuana industry boom caused assorted legislators to believe one was needed anyhow.

Legislation from 2011 and 2012 would have established THC intoxication at five nanograms per milliliter of blood and made this standard per se -- meaning that a test registering five nanograms or more would be seen as irrefutable proof of intoxication. In response, critics argued that because THC tends to linger in users for longer periods of time, it's next to impossible to determine actual impairment via a blood test, at least under presently available technology.

This year, the five nanogram limit was still part of the legislation, originally known as HB 1114, but the per se language vanished from the measure, sponsored by Representative Rhonda Fields. Instead, the text referred to "permissible inference," which would allow people who register at five nanograms or above to present other evidence in court to prove that they weren't actually impaired, rather than being considered guilty as a result of the test reading.

Marijuana attorney Rob Corry saw this change as only a slight improvement over the previous legislation, making the new proposal 95 percent bad as opposed to 100 percent.

However, Fields, who's also the sponsor of 1114's sequel, HB 13-1325, considers the standard to be necessary given what's thought to be increased marijuana use in the area due to previously existing medical marijuana laws and the signing of Amendment 64, which allows adults 21 and over to use and possess small amounts of cannabis recreationally in Colorado. Moreover, in an interview last month, she expressed confidence that innocent people wouldn't be convicted as a result of the limit.

"The bill looks for active THC in the system, not inactive THC," she told us. "If someone is a chronic user, like medical marijuana patients who use it as part of their treatment, we won't be looking at something that's residue. We'll only be looking at the active THC level."

This argument didn't convince the Senate Judiciary Committee, which rejected 1114 due in part to a new U.S. Supreme Court ruling against warrantless blood draws after drunk-driving arrests. But the THC limit was reintroduced, and thanks in part to pressure from law-enforcement groups, which said in a letter to Governor John Hickenlooper that passing marijuana laws without such a standard would be irresponsible, the measure gathered steam.

In the end, it appears that a majority of legislators decided that passing a dubious law that may result in innocent people being prosecuted would be politically better than to be seen as doing nothing after retail pot operations open and potentially tens of thousands of additional marijuana smokers hit the streets.

Problem is, medical marijuana patients' regular use of cannabis means their system is always over the five nanogram limit. For proof, turn to a 2011 post in which MMJ critic William Breathes's blood tested at nearly triple the legal limit fifteen hours after he last smoked, with a doctor declaring him to be sober.

Look below to see that entire article, which puts into context the way the soon-to-become law places patients like Breathes at risk in the name of safety.

Continue for William Breathes's original post about blood testing and lingering THC. "THC blood test: Pot critic William Breathes nearly 3 times over proposed limit when sober" By William Breathes April 18, 2011

Last week, in advance of today's Senate debate over a bill that would set THC driving limits, I had blood drawn (for a second time) to see just how much active THC was in my blood even after a night of sleep and not smoking for fifteen hours.

As it turns out, I've got a lot. So much that I and thousands of other medical marijuana patients may be risking arrest every time we drive if the measure passes. Even when deemed sober by a doctor, my active THC levels were almost triple the proposed standard of 5 nanograms per milliliter of blood.

Among the concerns about HB 1261, the THC driving bill first offered by Representative Claire Levy, is the fact that THC can stay in the body days after patients medicate. And my latest test offers proof.

The lab ran a serum/plasma test which showed my THC count to be at 27. According to Dr. Alan Shackelford, who ordered the blood work and evaluated my results, the number of active THC nanograms per milliliter count is about half of that total, or 13.5 nanograms of THC per milliliter of blood.

In short: If this bill passes and I was pulled over by police, I would be over the limit by 8.5 nanograms. By that logic, I would be more likely to have mowed down a family in my car on my way to the doctor's office that day than actually arriving there safely. But I didn't -- because I wasn't impaired.

Don't take my word for it. According to Shackelford, who evaluated me before writing the order to have my blood drawn last Wednesday, I was "in no way incapacitated." According to him, my test results show that it would not be uncommon to see such a high level in other people who use cannabis regularly -- like medical marijuana patients. "Your level was about 13.5 for whole blood... which would have made you incapacitated on a lab value," he said. "They need to vote this sucker down based on that alone."

Frankly, I didn't even need to go through this effort to prove that. Levy appears to understand that the limit might unintentionally hurt patients like me, since she's shared her concern that 5 nanograms is too low. Yet the bill still moved through to the senate.

Now, with some actual proof from a Colorado medical marijuana patient that this is the case, could someone curb this bill?

The Senate Judiciary Committee will discuss HB 1261 today at 1:30 p.m. at the Capitol Building. The hearing will offer the last time public comment will be heard about the proposal.

More from our Marijuana archive: "THC driving limits could cause more innocent people to spend months in jail, attorney says."