Irish Saliva Test for THC Would Prosecute “Completely Sober” Drivers


The Transportation Minister of Ireland, Pascal Donohoe, is speaking out in favor of a new per se DUID law that allows the gardaí (Irish police) to test drivers’ saliva for the active THC from recent cannabis use.

On the radio show Morning Ireland, Donohoe was asked if “completely sober” cannabis users could be prosecuted, to which he answered, “Yes.”

Donohoe seems untroubled by the science of THC in the human body. In a 2001 study published in Journal of Analytical Toxicology, researchers had subjects smoke a single joint containing 20 milligrams to 25 milligrams of THC. For comparison’s sake, this article explains how “a one-gram joint of 2% THC cannabis typically contained about twenty milligrams of THC.”

With subjects smoking just one weak joint of Woodstock Weed, researchers found that saliva testing gave positive results following smoked marijuana consecutively for average periods of 13-15 hours, plus or minus 2 hours, depending on testing method. That means for at least half a day, no chance of testing negative.

The last positive test THC detection times were 31-34 hours, plus or minus 9 hours, depending on testing method. So, indeed, someone completely sober the next day could still test positive on a saliva test.

That’s testing positive with a threshold of 0.5 to 1.0 nanograms of THC per milliliter. Ireland’s new law mentions only that the driver needs to test positive – not like Colorado and Washington’s five-nanogram limits. Ireland’s new law is essentially a zero tolerance per se DUID law.

Now consider that nobody these days is smoking 2 percent THC joints. A one gram of modern marijuana “could contain 250 milligrams of THC,” according to the aforementioned article.

This scientific understanding has the Irish media running headlines like “‘Completely sober’ drivers who smoked cannabis in last week could be prosecuted under new laws.” But the Transportation Minister isn’t moved by the plight of unimpaired drivers, believing instead that cannabis users are dangerous by virtue of simply being cannabis users.

“We have a growing amount of evidence that indicates very clearly that the presence of drugs like that can impair your ability to drive a vehicle safely,” Minister Donohoe told Morning Ireland. “Over a 10-year period… just under 10 percent of people who tragically lost their lives did have drugs in their system, and out of that 10 percent of people, between 60-70 percent of them had cannabis in their system.”

That’s the minister conflating the presence of a drug in a traffic wreck victim with an impaired traffic wreck victim. That’s reasonable when you’re talking about alcohol and most drugs, but as we’ve just pointed out, the detection of active THC isn’t always correlated with impairment.

Don’t believe me. Believe the United States’ National Highway Traffic Safety Administration (NHTSA). In their Fact Sheet on cannabis, they state that “It is difficult to establish a relationship between a person’s THC blood or plasma concentration and performance impairing effects” and that “It is inadvisable to try and predict effects based on blood THC concentrations alone.”

NHTSA continues by explaining that “Effects from smoking cannabis products are felt within minutes and reach their peak in 10-30 minutes. Typical marijuana smokers experience a high that lasts approximately 2 hours. Most behavioral and physiological effects return to baseline levels within 3-5 hours after drug use.”

The US government even gives their tacit blessing of driving by people who develop tolerance to THC. The feds recognize synthetic THC pills called Marinol® as a prescribable Schedule III drug. With a bottle of Marinol® is the following warning: “The drug manufacturer suggests that patients receiving treatment with Marinol® should be specifically warned not to drive until it is established that they are able to tolerate the drug and perform such tasks safely.”

The new Irish zero tolerance per se DUID law has nothing to do keeping the roads safe. The Transportation Minister even admits it will prosecute “completely sober” drivers. This law is just another measure of legalized discrimination against cannabis consumers.