Fentanyl is increasingly turning up in U.S. workplace drug tests, particularly during random screenings, according to the 2025 Quest Diagnostics Drug Testing Index.
The analysis of more than 8 million tests found that overall workplace drug positivity declined slightly in 2024, dropping to 4.4% from 4.6% the year before. But fentanyl results told a different story. Random screenings showed fentanyl positivity rates of 1.13% — more than seven times higher than pre-employment tests at 0.14%. That sharp contrast suggests more employees may be using the powerful opioid after passing initial job screenings.
The report also found that 60% of fentanyl-positive tests included at least one other drug, most often marijuana or amphetamines.
“The new Quest data indicates a worrying increase in fentanyl positivity in random drug tests as well as fentanyl drug-combining among the nation’s workforce,” said Suhash Harwani, PhD, Senior Director of Science for Workforce Health Solutions at Quest Diagnostics, in a press release. “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.”
Marijuana remains the most common drug detected in the workplace, with positivity steady at 4.5% in 2024. Post-accident marijuana positivity also remained high at 7.3%, just under the record 7.5% reported in 2023. Among federally mandated, safety-sensitive workers, marijuana positivity declined slightly to 0.87% from 0.95%.
