Eight New York Police Department officers were taken to the hospital early Friday after entering an alleged drug lab in Queens and inhaling fumes believed to have been from a highly toxic synthetic opioid, law enforcement sources said.

The officers complained of light headedness and nausea after responding to a pre-dawn call at the six-story building in Rego Park. Police sources believe they were sickened by fumes from the drug fentanyl, reports NBC New York.

Officers initially had been called about a man who appeared to be high on heroin; that man was taken into custody. The apartment may also have been a drug mill, a place where street drugs are mixed. In this case, it's believed heroin was being mixed with fentanyl, a growing trend.

The entire midnight shift of the NYPD's 112th Precinct ended up needing medical care. They are all expected to be OK, the sources said.