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Marijuana testing FAQS

Yup. We get questions all the time about marijuana. Here are common questions and the way we answer them:
Isn’t marijuana use legal? Yes and no: Washington and other states have legalized marijuana use. BUT it is still illegal on federal levels, so if you’re working for the US government or doing activities (e.g., a CDL trucker) that are regulated by the federal government, you may not use marijuana, regardless of your home state. I’m an employer, with no federal contracts. Should I have a drug free workplace? Worker Care recommends having a drug free workplace for anyone whose employees operate machinery (Anyone drive for work? To work?), or make decisions or perform tasks that can affect their safety and that of others. If you do decide to have a drug-free workplace, please make sure you have a drug -free policy that explains what drugs are prohibited, how you’ll monitor that, and what the consequences of a positive result would be. Okay, so I have a drug free workplace (no federal regulations). Should I take marijuana off the list of drugs? We don't recommend removing marijuana from your list of drug no-nos because it is well documented that marijuana impairment causes safety issues and, well, impairment. However, if you do choose to remove marijuana from your list of drugs, make sure that your liability insurance is okay with it, and that you are willing to take on the associated safety risks. One of my employees tested positive for THC (marijuana). Does this mean that the employee was high at work? Simply put, that is not what this means. The employee could have been high at work, but this test is not proof. What this test shows is that the employee has used THC in the past (sometimes up to 36 days ago), enough that it has not completely left the employee’s system. This could mean that the employee was using at work, but it could also mean the use was elsewhere. My employee swears he/she just uses CBD, but came out positive for THC. Why? CBD is derived from the same plant as THC. Many CBD products can contain low levels of THC. Someone who uses enough CBD products may end up with a positive THC result on a drug test. Although there are some expensive tests that break down how much CBD vs THCA (the one that makes you high) there is in the sample, it is important to consider when (and why) you would make an exception for someone who is getting that passive exposure. And then make sure to include it in your drug-free workplace policy! One of my employees got a HUGE number and another got a smaller number on their tests, but both are positive. Does this mean that one was more positive than the other? Nope. This means that they were both positive. The numbers do not reflect intoxication levels at the time of the collection. Even though the lab reports specific concentration numbers, if it is positive, it is positive. Period. An employee had a urine drug test and then followed up with a hair test after the positive urine test. The numbers on the hair test were different. Why? While the lab tests can both be performed using Gas Chromatography and/or Mass Spectrometry, the markers are stored differently in hair and urine, so the quantities are measured differently. The urine drug test will measure by ng/mL (nanogram per milliliter), and hair drug tests measure in pg/mL (picogram/milliliter). The other thing to note is that urine drug tests can capture use from 1 day to 36 days, and hair tests capture about 90 days’ worth of use. If the UDS can’t show that the person is high at the moment, what do we do if we think someone is high at work? While marijuana can definitely cause impairment, we don’t yet have a reliable, accessible real-time measurement of inebriation, so it is important to detect and document any clues that show your employee is impaired. Be on the lookout for slow speech, poor coordination, increased appetite, falling asleep on the job, red eyes, delayed reaction time, and/or a shift in mood. As you may suspect, this could also mean a medical issue, so if you see signs like these, remove your employee from any safety-sensitive tasks, and use a drug screen to rule out medical issues. What do I do if I have more questions? Give us a call at 509-575-3677 or email Even though we don’t know EVERYTHING, we’ll try our best to help you find your answers!
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