How do Marijuana Blood Tests Work?

If you are an active driver and you also like to take some time in your day to enjoy our beloved friend marijuana, you have probably wondered what is going to happen if you are happily driving down the road and suddenly you are pulled over. Since marijuana is now legalized in some American states for medical and recreational use, police had to find a way to test drivers to find out if they weren’t too high while driving their cars. Thus they “invented” blood testing on the road. They are still using roadside tests and demonstrated impairment to a Drug Recognition Expert, but police officers are all about blood testing people now. In some states if you are driving and you have more than 5 ng/mL of THC in your body, you could even get a DUI conviction. Although this is only the law in some states, the AAA Foundation for Traffic Safety says that this legal limit is “arbitrary and unsupported by science.”

How the blood tests work

Let’s see how this really works. These blood tests calculate how much THC the drivers have in their body, and undoubtedly, that the driver is under the influence of THC. Unlike a case of drunk-driving, the driver is not allowed to refuse the blood test. If you are a drunk driver and still refuse the blood test you will get your license revoked and face harsh penalties. After saying yes, a nurse or a paramedic will draw the sample and if this sample has more THC than the legal limit, the driver will face some serious penalties as DUI including license suspension, fines and potentially some jail time.

With all that being said, these blood tests are questioned by experts. Studies have shown that only two hours after using marijuana, the level of THC in their blood dropped an average of 5 ng/mL and takes around 165 minutes from the first contact with the police until the blood is drawn from the driver. This legal limit is too low for a regular user of cannabis, which can create some serious consequences to the driver even if they did not recently use cannabis. This level of the THC can maintain in their bodies for days. Therefore, even if they are sober they can face serious penalties from the police. Sadly, this is the most effective and trusted way to prove impaired drivers according to the police.

Ok now I’m too afraid to drive…

Nobody should be charged from getting high yesterday, and driving today. That simply does not make sense. There needs to be an alternative to these blood tests. Sure there is definitely a level of being “too high to drive.” But who is in charge of that threshold? Also, a BAC of 0.08 is much more likely to effect your motor skills than 5 ng/mL of THC. Those who self-medicate can have residual blood levels of THC well above that.

It’s safe to say if you are a frequent cannabis user that you could be well above the legal threshold and not feel high or impaired in the slightest. The blood test is simply not accurate enough for the information that it needs to calculate, how impaired a driver actually is.

As with everything marijuana, the fight continues.