Widespread legalization of marijuana has created safety concerns for employers and insurers in the construction sector, which has some of the highest rates of workplace injuries. 

Employees in some safety-sensitive positions are still barred from using the drug even in states where it has been decriminalized for medical and recreational use, but for most companies in the construction sector, where finding qualified workers can be tough, the situation is complicated, experts say.

Drug testing protocols designed for an earlier era are not effective in identifying workers impaired by marijuana use, and proven alternatives are often unavailable, they say. 

Medical marijuana is permitted in 38 states and recreational marijuana in 23 states — both forms are authorized in Washington D.C. — but the drug remains illegal under federal law. The conflicting legal environment has employers seeking ways to determine whether workers are under the influence of the drug in order to stave off workplace injuries and some of the costliest workers compensation claims.

It isn’t easy, said Megin Gallagher, risk manager for Krusinski Construction Co. in Oak Brook, Illinois. Marijuana has been legal for recreational use in the state since 2020. 

Given the conflicting state and federal laws, the contractor only tests for marijuana if it is made aware of possible worker impairment, she said. The situation becomes more complex when supervisors aren’t immediately informed of job site incidents. 

“These are all obviously concerns and things that we’re constantly trying to figure out,” Ms. Gallagher said. “It is a constant struggle.” 

Workers determined to be impaired by marijuana or other substances can be removed from a job site, but the employees must be replaced, which can cause work stoppage issues, she said. 

“That’s kind of where we’re at right now,” Ms. Gallagher said. “We’re doing the best we can within the parameters that we’re able to work with.”

Legal marijuana is a growing concern for construction employers, more so than other industries, because of the safety factor, said Brian Allen, Salt Lake City-based vice president of government affairs for Mitchell Pharmacy Solutions, an Enlyte Group LLC subsidiary.

“I don’t think it’s any secret that heavy equipment and impairment really don’t mix well,” Mr. Allen said. “And having people in construction jobs up on roofs, climbing scaffolding, doing things where their motor skills may be impaired by the use of marijuana could be really very problematic.”

Testing

Data on workplace injury rates where marijuana impairment was a factor is lacking, partly due to inadequate testing.

“It’s difficult to get the testing. It’s difficult to prove that the marijuana was an actual contributing factor” in a workplace injury, said Kevin O’Sadnick, senior risk control manager with St. Louis-based Safety National Casualty Corp. 

Traditional testing — through urine, blood or hair — just looks for the presence of marijuana because it has long been illegal at the federal level, so impairment was never considered, experts say. 

“There’s nothing that’s reliable at this point” in terms of drug tests, said Elizabeth Yohe, a Palm Beach Gardens, Florida-based workers comp defense lawyer with Vaughan Baio & Partners. 

Urine testing detects marijuana metabolites, or chemical remnants of the plant, but doesn’t differentiate between psychoactive compounds that cause impairment and non-psychoactive compounds, according to Secaucus, New Jersey-based clinical laboratory Quest Diagnostics. Urine tests also don’t measure impairment or time of consumption. 

Blood tests are better indicators of recent use, because they measure active levels of THC — the compound that gives pot its high — in a person’s system. Hair tests are more likely to measure chronic exposure. 

Complicating matters, people process the drug differently and impairment can be affected by weight, use frequency, genetic composition and digestive functions, among other things, according to Quest. 

In May, Quest released findings that show the percentage of employees in the U.S. workforce testing positive for marijuana following a workplace accident increased in 2022 to its highest level in 25 years. Post-accident marijuana positivity jumped from 6.7% in 2021 to 7.3% in 2022. 

The building trades continue to implement “very stringent drug testing” as drug legalization expands, said Marianne Karg, West Lake, Ohio-based vice president of Mobile Medical Corp., which provides occupational drug testing.

“Although workplace testing is very effective at identifying the presence or absence of THC … what we never had to do in workplace testing was isolate recent use,” said Nina French, president of employer and law-enforcement solutions for Hound Labs Inc., a portable technologies development company. 

The Oakland, California-based company announced in September that Quest had agreed to provide lab services for the Hound Cannabis Breathalyzer, a device designed to detect and measure workplace cannabis use.

Hound Labs said Quest will use mass spectrometry — an analytical tool designed to measure the mass-to-charge ratio of molecules present in a sample — to confirm positive marijuana results generated by the breathalyzer. 

There may be conflict between employers that want to eliminate marijuana from drug policies due to legalization and insurers that believe the move would place companies at risk, Ms. Karg said. 

Some construction companies that are eliminating marijuana testing are doing so because of the perceived difficulty in attracting qualified workers, since fewer workers may pass drug tests in legal marijuana states, she said (see related story). 

Risk mitigation

While preemployment marijuana testing is outlawed in some jurisdictions — the practice is banned in Michigan, Washington D.C. and Washington state — concern remains regarding on-the-job impairment, leading construction employers to investigate other ways to keep job sites safe, experts say. 

“At this point, from everything I’ve seen and read, risk managers are staying in line with zero tolerance in the construction industry. There’s just not a lot of room for leeway,” said Ms. Yohe of Vaughan Baio.

In September, the Associated General Contractors of Minnesota announced that building contractors must rely on drug-free workplace policies pending further guidance from courts or lawmakers. 

While employers attempt to mitigate marijuana-related risks, workers and labor unions are also concerned about the issue, because employees want to feel safe on the job, said Mike Schechter, general counsel and director of labor relations for the Minnesota organization.

“There’s an absolute huge concern, and this isn’t limited to marijuana,” he said, adding that any intoxicant can affect workers’ reaction time and make them less aware of their surroundings.

“Those are huge recipes for tragic consequences,” Mr. Schechter said. 

One strategy is to train employees in “observational testing” and encourage them to bring coworker impairment concerns to management, he said. 

Addressing marijuana use in construction is also complicated by the interplay between state laws, federal laws, court rulings, individual company policies and labor unions.

While employers are concerned about workplace marijuana impairment, off-the-clock use isn’t as much of a worry, Mr. Schechter said. However, current drug testing for THC can give a false sense of whether a worker is impaired because THC can remain in a person’s system for weeks after use, he said. 

“It causes big problems with risk managers and trying to determine what they can and can’t do,” said Jeff Sandy, vice president for workers compensation brokerage for Jencap Group LLC in Lee’s Summit, Missouri. 

In addition, companies must determine whether workers who are prescribed medical marijuana are governed by the same rules as recreational users (see related story). 

“This is a real issue that you just can’t take a real quick swipe at and say, ‘This is what we’re going to do, this is what we’re not going to do,’” said Carl Heinlein, Wexford, Pennsylvania-based senior safety consultant with the American Contractors Insurance Group. “The industry is kind of peeking over the fence line looking at what everybody else is doing.” 

Whether companies are including, or excluding, marijuana in their drug policies can vary from job to job and state to state, Ms. Gallagher said, adding that whether jobs are unionized can add another layer of complexity, because union jobs have rules that companies cannot violate.

“We don’t have a lot of leeway,” she said. 

Pushback

Construction employers are familiar with alcohol impairment as a workplace hazard, Mr. Allen said, but identifying marijuana intoxication can be more difficult, as the signs tend to be more subtle. 

And there’s pushback: A 2020 review published in the journal Substance Use & Misuse stated that evidence doesn’t seem to support the position that cannabis users are at an increased risk of occupational injury. 

Some states are beginning to put in place protections for workers who use recreational marijuana outside of work, further tying the hands of employers, Mr. Allen said. 

California, Connecticut, Montana, New Jersey, New York and Rhode Island have enacted workplace protections limiting employers’ ability to test for off-the-job marijuana use, according to the National Organization for the Reform of Marijuana Laws. 

Even in states where marijuana is legal, there are some professions that ban the use of the drug, including construction jobs under federal contracts and interstate trucking positions governed by the U.S. Department of Transportation, said Jenifer Kaufman, an Abington, Pennsylvania-based workers comp attorney. 

Construction jobs not regulated by the federal government are subject to state laws, internal company policies and collective bargaining agreements. 

“Laws and regulations are changing very rapidly and that’s going to require companies who work in those states and who operate in those states to be really up to date with the laws,” said Michael Jorda, a New York-based risk control consultant with Lockton Cos. LLC. 

Given the changing landscape, it’s important that construction employers start addressing the marijuana issue just like they would any other workplace risk, Mr. Jorda said.