RICHMOND, B.C. -- Officials say two border agents have been taken to hospital after they were exposed to a "suspicious substance" at a Canada Post facility in Richmond, B.C.

Tim Wilkinson, deputy chief with Richmond Fire, said firefighters were called Tuesday afternoon for reports of a potential hazardous materials situation after a powder was found in a sorting facility adjacent to the Vancouver International Airport.

Crews arrived to find two people who may have been exposed to the powder suffering from elevated heart rates and shortness of breath, he said. Twelve others who may have been exposed to the powder were isolated and monitored.

The Canadian Border Services Agency confirmed two border services officers were taken to hospital as a precautionary measure after they came into contact with a "suspicious substance."

Preliminary tests on the substance did not show that fentanyl or its analogues were present, the agency said in a release.

It said further testing is being done to determine what the substance is and the matter is now under investigation.

Where the powder came from is unclear, but fire crews stayed on site until it was determined the substance was not a biohazard or a narcotic, Wilkinson said.