The U.S. Postal Service distribution center in Scarborough will test emergency responses to anthrax in a biohazard exercise with local, state and federal agencies on Tuesday.

Postal Service Way will be closed during the drill, which begins at 6 p.m. and ends around 9:30 p.m.

The postal service is equipped with on-site equipment known as a Biohazard Detection System or BDS. The BDS collects hourly air samples that are analyzed to determine whether anthrax is present. The entire sampling and testing process is automated. If the BDS detects anthrax, the system shuts down the operation and sounds an alarm to evacuate the plant.