Fentanyl and its analogs pose a potential hazard to law enforcement, public health workers, and first responders who could unknowingly come into contact with these drugs in their different forms. Police working dogs are also at risk of exposure. Possible exposure routes vary based on the source of the fentanyl. While dermal absorption of fentanyl commonly occurs through prescribed use of the drug, inhalation of powder is the most likely exposure route for illicitly-manufactured fentanyl. Inhalation exposure can quickly result in respiratory depression. Law enforcement personnel may come into contact with these drugs on the street during the course of law enforcement activities. The DEA recommends that officers do not field test drugs if fentanyl is suspected. The substance should be collected and sent to a laboratory for analysis. Exposure via inhalation or skin absorption can be deadly.
First responders may also encounter violent behavior from the user when naloxone is used to reverse respiratory depression as it may put the user into withdrawal.
NIOSH has conducted Health Hazard Evaluations (HHEs) involving law enforcement and emergency responder exposure to hazardous substances at crime scenes. https://www.cdc.gov/niosh/topics/fentanyl/risk.html