South Dakota drug enforcement officials are concerned about the influx of a dangerous painkiller that is now being cut into heroin.

Fentanyl is a synthetic opioid that is similar to morphine but 50 to 100 times more potent, according to the National Institute on Drug Abuse. The drug can be disguised into phony prescription oxycodone pills, and it’s now being cut into heroin by drug dealers to intensify users’ highs.

Fentanyl poses a particular danger to law enforcement officials and K-9 units, as accidental exposure can be fatal.

Recent South Dakota media reports show that fentanyl is making its way into South Dakota.

Last week, authorities seized some 20,000 fentanyl pills and arrested a 19-year-old man after issuing a search warrant in Chamberlain, according to an AP report. One officer was treated for exposure as a precaution but was released from the hospital, according to the attorney general’s office.

The Chamberlain bust followed the April arrest of a Mitchell man found with 1,000 fentanyl pills, according to the Daily Republic. Mitchell Police Det. Lt. Don Everson told the newspaper that although the drug has been present in town for years, officers are now finding it in powdered form, and with its high potency and small particles, the powder can kill someone when inhaled.