More states are legalizing the recreational use of marijuana, and it seems that companies are now seeing the impacts of such legislation, including those in the construction and manufacturing industries.

According to the Quest Diagnostics Drug Testing Index, the rate at which employees in the general U.S. workforce are testing positive for marijuana following on-the-job accidents is at its highest level in a quarter century. Data from the index indicates that the construction and manufacturing industry’s positivity rates have increased by 14.6% and 21.6% since 2018, respectively.

According to the Quest Diagnostics Drug Testing Index, the rate at which employees in the general U.S. workforce are testing positive for marijuana following on-the-job accidents is at its highest level in a quarter century. Photo courtesy of Sandy Millar.

Quest’s data adds that post-accident marijuana positivity rose to 7.3% in 2022 from 6.7% in 2021. That’s the highest the rate has been in 25 years. Quest officials note a steady increase in such positivity each year starting in 2012. Within the past decade, post-accident marijuana positivity has increased by more than 204%, while those rates declined from 2002 to 2009.

Officials from the diagnostics company say the increase corresponds with marijuana legalization in a number of states. For example, Colorado and Washington State both legalized recreational marijuana use in 2012, with 19 states and Washington, D.C., following suit since that time. Even more states, 38, have legalized medical use. Both recreational and medicinal use of marijuana are illegal under federal law.

“Intoxicating cannabis products, including marijuana, can have a major impact on safety at work and have been proven to slow reaction time, impact memory and impair skills essential to driving. State legalization of the drug creates new challenges for employers,” says Katie Mueller, a senior program manager at the National Safety Council focusing on cannabis safety. “The Quest data provide compelling evidence that increased use of cannabis products by employees can contribute to greater risk for injuries in the workplace.”

The combined U.S. workforce urine drug positivity for all drugs remained at 4.6% in 2022, which is still the highest level in 20 years. Positivity rates for 2021 and 2022 were the highest since 2001, increasing by more than 30% from all-time lows in 2010-12. Quest also notes that marijuana is not the only culprit.

“Positivity for marijuana in the general U.S. workforce increased 10.3% … amphetamines positivity increased 15.4% … While the company’s data for amphetamines does not differentiate between prescribed medications and illicit drug use, the increase correlates with other data suggesting that the use of amphetamines, prescribed or illicit, has grown in recent years in the U.S.”

In 2022, marijuana positivity increased by 17% in states that legalized recreational marijuana. That rate increased by 5.9% in states with legalized medical marijuana. Marijuana positivity also increased in states without any form of legalization, rising 12.7% year-over-year. However, officials note that positivity rates are still higher in states with marijuana legalization.

“Our 2022 Quest Diagnostics analysis shows that the overall U.S. workforce positivity rate continued to be at a historically elevated level in 2022, even as much of the nation’s workforce returned to the office post-pandemic,” says Keith Ward, general manager and vice president for employer solutions at Quest. “This historic rise seems to correspond with sharp increases in positivity for marijuana in both pre-employment and post-accident drug tests, suggesting that changing societal attitudes about marijuana may be impacting workplace behaviors and putting colleagues at risk. The increase in amphetamines positivity is also notable, given the addictive potential and health risks associated with this class of drugs.”


  1. But we can be drunk the night before and go to work the next day. Theses companies are so full of crap.

  2. With any controlled substance there is a learning curve and a need to monitor use as it relates to “appropriate”. This is complicated by the unique effect that each substance has on different individuals and their propensity toward use and/or abuse. I have used marijuana off and on for fifty years and currently have a prescription for chronic pain. The formulations of today’s products include THC, CBD and other additives such as L-theranine that alter the results of each dose. Companies can set limits, but it is ultimately an individual’s responsibility to manage usage. Good luck with that.

  3. How many of them were doing pot own the job and how many people did I at home and not the on the job because I never did it on the job when I did it most of the time I did it was to wind myself down and relax and let the pain quit hurting and let my mind relax to it was helping me and I didn’t go to work high are do it on the job that is what the drug testing is not saying they want people to be afraid so they can keep it illegal they need a test to tell when a person is doing it on the job are not

  4. That doesn’t mean more people are high while at work. It stays in your system for days or weeks for regular smokers. This data may be right, but by no means equates to greater risk at the job. Frankly, I’m far more concerned about the drinker who comes to work hung over from the night before, than the smoker from the night before. Funny how alcohol is far worse for society than Marijuana, but yet it’s legal and still more accepted.

  5. I totally agree with your comment. When marijuana is respected and used properly you can get the full medicinal benefits out of the plant. The problem is you have young people just smoking the hell out of it before and during work. Most can’t do their job sober let alone high and that’s a real problem.

  6. OK how many were tested for alcohol and other substances that can cause accidents I bet when prohibition ended drunk driving and alcohol related issues skyrocketed too.

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