SHAW AIR FORCE BASE, S.C. - Senior Airman William Fritter receives his gas mask fit test from Senior Airman Earl Barnes, both Airmen are bioenvironmental journeyman from the bioenvironmental flight, after completing his quantitative fit test, May 1. This will be the only quantitative fit test Airman Fritter will need according to Air Force Occupational Safety and Health Standard 48-137, unless a new type of mask is issued, 10 percent of body weight is lost or gained or extensive dental or facial surgery is performed. (U.S. Air Force photo/Senior Airman William Coleman)