Hazardous-materials teams decontaminated 12 workers at the federal prison in McCreary County Tuesday after employees in the facility mail room found a powdery white substance in an envelope addressed to a former inmate, authorities said.
Samples of the substance were flown to Frankfort to be analyzed at the state crime lab. The results came back negative Tuesday night for any toxic substances, said Buddy Rogers, spokesman for the state Division of Emergency Management.
The FBI is investigating the case.
Earlier, two prison employees showed minor symptoms potentially related to a toxic substance during the decontamination process and were taken to the hospital in Somerset for treatment as a precaution, Rogers said.
However, those reactions — including shortness of breath — also could have been related to stress, he said.
“Going through decon is pretty stressful,” Rogers said.
If the employees were at serious risk, they probably would have shown symptoms earlier, Rogers said.
Officials stressed that there is no danger to the community or the prison population from the substance.
Rogers said the incident was reported about 11 a.m. Tuesday. Prison employees were screening incoming inmate mail and found the powder when they opened an envelope addressed to a person previously housed at the facility.
The prison said in a news release that the mail room is a limited-access area and was sealed off immediately. No inmates came into contact with the powder.
The prison would not release additional details.