WASHINGTON – The Drug Enforcement Administration has long warned potential users of the dangers of fentanyl, a powerful synthetic opioid that often contributes to overdoses and is sometimes laced in heroin or cocaine.

Now they’re worried about the substance’s effect on a different group: The police and firefighters who might touch or inhale it incidentally while on the job.

The DEA on Tuesday released a video targeted at emergency responders who might come into contact with fentanyl, warning them to take care if they see any sort of white powdery substance.

“Assume the worst,” Acting DEA Administrator Chuck Rosenberg says in the video. “Don’t touch this stuff or the wrappings that it comes in without the proper personal protective equipment.”

The video features two New Jersey officers who were both sickened merely by handling the drug. Officials at a news conference at DEA headquarters on Tuesday referenced an ever grimmer case of an Ohio officer who passed out about an hour after merely brushing the substance off his shirt with his bare hand. That officer had to be revived with four doses of Narcan, a drug that blocks the effects of opioids and that officers use to try to treat an overdose.

As they released the video, DEA and Justice Department officials said they were alarmed by the recent influx of fentanyl and of drug overdoses generally. In 2015, Deputy Attorney General Rod J. Rosenstein said, more than 52,000 people in the United States died due to drug overdoses – 33,000 from heroin, fentanyl and other opioid drugs. He said preliminary numbers for 2016 showed an increase to almost 60,000 deaths.

“Some people say we should be more permissive, more tolerant, more understanding about drug abuse,” Rosenstein said. “I say we should be more honest, and we should be forthcoming with the American people about the clear and present danger that we now face.”

Attorney General Jeff Sessions has taken a hard-line stance toward drug use. Last month, he directed his federal prosecutors to pursue the most severe penalties possible, even when those included mandatory minimum sentences. That directive reversed the previous administration’s charging policy and signaled a return to the so-called war on drugs.

Civil rights groups, Republican lawmakers and even the conservative Koch brothers issued swift condemnations of the policy, though the National Association of Assistant United States Attorneys, which represents federal prosecutors, embraced it.

Rosenberg said he routinely charged the “most serious readily provable offense,” as Sessions had directed, during his days as a prosecutor.

“And so I think that makes sense,” Rosenberg said. “We have to be thoughtful. We have to be judicious. He’s not asking us to do anything but that.”