Occupational exposures to illicit drugs in forensic science divisions

Forensic scientists from local, county, state, and federal law enforcement agencies analyze evidence daily in which unknown substances suspected of containing illicit drugs are handled, weighed, and chemically processed. To address concerns about potential occupational exposures to opioids like fentanyl and other illicit substances, the National Institute for Occupational Safety and Health (NIOSH) conducted a multi-site exposure assessment among forensic laboratory personnel. NIOSH evaluated personal and area air samples, handwipe samples, area surface samples, and personal biomonitoring urine samples for cocaine, fentanyl, heroin, methamphetamine, and other metabolites. Thirteen of the 91 personal air, time-weighted average (TWA) samples collected exceeded the American Conference of Governmental Industrial Hygienists (ACGIH)^® Threshold Limit Value (TLV)^® for fentanyl of 100 ng/m³ (8 h TWA), with exceedances observed at 4 of 11 sites. The ACGIH Surface Limit (TLV-SL) of 10 ng/cm² for fentanyl was exceeded for 8 of 86 surface wipes taken in laboratories at 3 of 11 sites. Commonly touched surfaces found to be above the TLV-SL included laboratory scales, keyboards, return air vents, the top of a light fixture, and inside a laboratory hood. Similarly, there were detectable concentrations in air and surface samples for cocaine and methamphetamine. Eight of 11 sites had at least one person with some detectable level of an illicit drug or metabolite in a urine sample. Based on the results of the current study, safety thresholds for fentanyl were exceeded. For other illicit drugs such as methamphetamine, cocaine, or heroin, thresholds have not been established to protect these workers. Due to the unpredictable nature of the evidence being handled, prudent occupational safety calls for minimizing exposure to chronic low doses of illicit drugs, as the health effects are unknown. To minimize exposure risk, best practices were identified from the literature and provided to each laboratory. Since potential health hazards have not been clearly established for chronic low-dose exposures, more research could lead to a better understanding of the potential health effects, if any, on workers.