The Defense Department has purchased 80,000 "escape masks" to protect employees and visitors against chemical and biological attacks and will begin distributing them next week at the Pentagon and 46 other leased buildings in the area, defense officials announced yesterday.

Lt. Cmdr. Jeff Davis, a Pentagon spokesman, said the Survivair Quick 2000 masks, which cost $150 apiece, would enable employees, contractors and visitors to safely make their way out of a building or area that has been attacked with poisonous chemicals or biological toxins. The masks, which come packed in a vacuum bag, would not be reusable.

Davis said everyone working at the Pentagon and leased buildings would receive training when they are issued a mask, which they will have to sign for. The Defense Department will distribute about 500 masks a day, starting next week, he said. Caches of masks will be stored throughout the Pentagon for use by visitors.

The masks, manufactured by Quick Protective Systems Inc. in Stuart, Fla., have been tested at the Edgewood Chemical Biological Center at the Aberdeen Proving Ground in Maryland.

The Quick 2000 is a hood that covers an individual's head and fastens around the neck. It has a breathing cartridge made of military grade carbon and "provides protection against a wide range of deadly particles and gases," according to Quick Protective Systems' Web site.