Random drug screenings nationwide are catching workers using fentanyl — and those users increasingly are mixing that potentially lethal opioid with marijuana and amphetamines, according to a major testing firm.
The 2025 Quest Diagnostics Drug Testing Index reveals troubling trends in fentanyl use among employees that experts say could pose health and safety issues in the workplace.
Fentanyl, a synthetic opioid that is 50 to 100 times stronger than heroin, has been linked to the majority of fatal drug overdoses on Staten Island and nationwide.
Overall, the number of workers caught using drugs throughout the United States remains relatively small and is on the decline. The report analyzed more than 8 million drug tests showed that positive drug tests in the workplace dipped slightly last year to 4.4% from 4.6%.
However, the report indicates that a significant number of workers who use fentanyl also are taking other drugs. About 60% of tests that were positive for fentanyl last year indicated the presence of additional drugs. About 22% of those tests found marijuana, a rate that has more than doubled since 2020 when 10% of fentanyl positives dinged for marijuana. Following workplace accidents, 7.3% of employees tested positive for marijuana last year.
Amphetamines weren’t far behind marijuana in co-use with fentanyl. According to the report, 16% of fentanyl-positive tests also indicated the presence of amphetamines last year compared to 11% five years ago.
“It is disturbing to see increased use of fentanyl on the job and in combination with other drugs, given fentanyl’s extreme potency, which can increase risk of impairment, accidents, and potential overdose,” said Suhash Harwani, PhD, senior director of Science for Workforce Health Solutions at Quest Diagnostics.
A puzzling result in the report is that fentanyl is over seven times more likely to be detected in random drugs tests done after employees are hired than during pre-employment screenings.
Quest said in a news release that “the sharp increase in fentanyl in random drug checks suggests more workers are using the highly addictive opioid after they have passed pre-employment screens.”
“It also raises concern that employees are turning to a dangerous drug like fentanyl after they’ve passed a pre-employment drug screen, putting the overall wellness of the workforce at risk,” Harwani said.