Nearly one in five workplace hair drug tests came back positive, according to new data from Quest Diagnostics. Hair testing can detect use over roughly 90 days and does not establish that an employee was impaired at work, but the findings point to an increase in recurring drug use. Quest reported that the share of positive tests has risen 46% since 2021.

The trend reinforces the importance of clear drug and alcohol policies, consistent enforcement and supervisor training, particularly in safety-sensitive positions involving machinery, vehicles and production equipment. Employers also must navigate the growing divide between changing marijuana laws and their responsibility to maintain safe operations.

“Manufacturers cannot run safety-sensitive workplaces on vague rules and wishful thinking,” said Dave O’Neil, director of communications and marketing for the Ohio Manufacturers’ Association. “Employers need clear policies, trained supervisors and the authority to act when safety is at risk, while recognizing that a positive test alone does not prove someone was impaired on the job.” 7/14/2026