Kansas City, Mo Emergency vehicles surrounded an office building near Union Station late Wednesday afternoon, when two workers reported they became nauseated after opening envelopes containing an unknown substance.
The incident took place in the Blue Cross-Blue Shield building, in the Crown Center area of Kansas City, Mo.
It wasn't immediately clear whether the two worked for Blue Cross-Blue Shield or another company in the building.
Brad Humston, spokesman for the Kansas City, Mo., Fire Department, said about 100 people were working on the floor at that time, but only two women were in the immediate area.
The building was closed but not evacuated.
He said the two reported they experienced nausea but said officials had not determined what the substance might be.
Humston said the two were given a soap and water decontamination and then were taken to a hospital.
Kansas City, Mo., Police Capt. Rick McLaughlin said the package was being turned over to the FBI, but he didn't know when its contents might be determined.
"We don't know what they had in there," he said. "Initial reports didn't indicate if there was anything in the envelope."
Hazardous material units from Lee's Summit, Mo., and Johnson County, Kan., were among those at the scene.
"Anytime we have a hazardous material we always bring a backup team as a precautionary measure," Humston said. "Originally we heard reports that there were possibly seven people with injuries. That's why there's such a large response."
Don Pickard, a spokesman for the Metropolitan Ambulance Services Transit, said the two women followed proper procedures in dealing with the substance.
"What we are seeing is training paying off," he said. "They opened it, became nauseated, and left it where it was."