Forensic scientists working in a police department crime laboratory were exposed to small but detectable amounts of fentanyl, cocaine, methamphetamine, and heroin during routine evidence handling, according to a health hazard evaluation conducted by the National Institute for Occupational Safety and Health (NIOSH). The investigation identified airborne, surface, and dermal contamination pathways, including one instance in which a scientist’s occupational exposure to fentanyl exceeded an occupational exposure limit established by the American Conference of Governmental Industrial Hygienists (ACGIH).

Although investigators found no evidence that the forensic laboratory drug exposure affected employee health, the results highlight safety risks associated with forensic drug analysis and underscore the importance of engineering controls, laboratory ventilation performance, and work practices in laboratories handling hazardous materials.

NIOSH conducted site visits in 2024 to evaluate forensic laboratory drug-exposure risks among scientists who routinely handle suspected drug evidence. Investigators collected personal air samples, surface wipes, hand wipes, and biological monitoring data to assess potential occupational exposure pathways.

Occupational exposure to fentanyl and stimulant contamination

Personal air sampling identified measurable exposure to multiple substances handled during forensic casework. One employee experienced a full-shift fentanyl exposure of 0.15 micrograms per cubic meter, exceeding the ACGIH occupational exposure limit of 0.1 µg/m³.

Methamphetamine was detected in personal air samples of all participating employees working in the forensic chemistry laboratory during both monitoring days. Cocaine was also detected in personal air samples of employees involved in casework containing the drug.

Surface contamination was widespread. Cocaine was present on all sampled surfaces inside and outside the laboratory, while fentanyl, heroin, and methamphetamine were detected on multiple laboratory surfaces, indicating potential contamination transfer beyond immediate work areas.

Biomonitoring results suggest low-level forensic laboratory drug exposure

Urine testing detected methamphetamine in three employees at levels far below clinical drug testing thresholds, suggesting possible low-level forensic laboratory drug exposure rather than substance use.

Investigators noted that biomonitoring alone cannot determine long-term exposure or distinguish occupational from non-occupational sources. However, when combined with environmental measurements and workplace observations, the findings indicate potential systemic absorption via inhalation, dermal contact, or inadvertent ingestion.

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Laboratory ventilation and engineering control challenges

The evaluation identified multiple laboratory ventilation and engineering control issues that could contribute to drug exposure risk. Some fume hoods operated outside recommended airflow ranges, with measured face velocities exceeding the recommended limits or falling below the effective containment threshold.

Employees also reported disabling ventilation during weighing procedures because turbulent airflow interfered with analytical accuracy. Such practices may increase airborne exposure potential and elevate occupational exposure to fentanyl risk.

NIOSH recommended improvements to laboratory ventilation systems, including ensuring that laboratory and benchtop hoods meet the specifications outlined in ANSI/ASSP Z9.5.

Work practices and contamination pathways

The investigation identified several exposure pathways beyond inhalation. Drugs were detected on employees’ hands both before and after work shifts, suggesting contamination transfer within and outside laboratory areas.

Factors contributing to forensic laboratory drug exposure risk included:

• Handling bulk evidence without consistent hood use
• Inconsistent glove changing and handwashing practices
• Surface contamination on frequently touched equipment
• Variability in cleaning protocols and decontamination methods
• Repeated handling of evidence during presumptive and confirmatory testing

NIOSH emphasized reducing workplace exposure to illicit drugs to the lowest feasible levels using established occupational health practices.

Implications for laboratory safety management

For laboratory managers, the findings highlight the importance of integrated safety controls when handling hazardous substances, particularly highly potent compounds such as synthetic opioids.

Recommended management strategies include:

• Verifying laboratory ventilation performance and hood certification
• Providing appropriate respiratory protection with fit testing
• Implementing standardized cleaning and decontamination protocols
• Improving communication between management and staff on safety procedures
• Providing annual training on exposure prevention and symptom recognition

NIOSH also recommended collaborating with law enforcement agencies and courts to address evidence packaging practices and reduce tasks that increase forensic laboratory drug-exposure risk, such as obtaining net weights of bulk materials.

Broader implications for laboratory environments

While the evaluation focused on a forensic laboratory, the findings have broader relevance for laboratories handling hazardous chemicals, unknown materials, or potent compounds. Exposure risks may arise from limitations in laboratory ventilation, workflow constraints, and pathways for contaminant transfer, even when protective measures are in place.

As laboratories continue to manage increasingly complex hazards, integrating engineering controls, administrative practices, and worker training remains essential for maintaining safe working environments.

This article was created with the assistance of Generative AI and has undergone editorial review before publishing.