Accession Number : ADA329091

Title :   Risk Assessment of Bacteriologic Health Hazards in the Helmet Bladder Component of a Pressure Breathing for G (PBG) System.

Descriptive Note : Technical rept.,

Corporate Author : DEFENCE AND CIVIL INST OF ENVIRONMENTAL MEDICINE DOWNSVIEW (ONTARIO)

Personal Author(s) : Severs, Yvonne D. ; Sabiston, Brian H.

PDF Url : ADA329091

Report Date : MAY 1997

Pagination or Media Count : 13

Abstract : One of the components of the experimental development G protection ensemble known as STING (Sustained Tolerance to INcreased C) is a breathing loop consisting of a pressurized oxygen supply, regulator, face mask, and an inflatable helmet bladder. The bladder, located in the back of the pilot's helmet, at the occipital level of the skull, inflates during the positive pressure breathing phase of the Pressure Breathing for C (PBG) cycle. The bladder is inflated to the same pressure as the mask, thus pulling the mask tighter to the face; preventing mask leakage; and, ensuring an adequate supply of pressurized oxygen to the user. Upon cessation of PBG, the helmet bladder deflates. The helmet bladder is effectively a blind sac' in an otherwise open system. This fact has prompted the Aerospace Engineering Test Establishment (AETE) to express concern over the possibility that the bladder could serve as a reservoir for microbiological contaminants (bacterial or fungal). If such contaminants were present, deflation of the bladder, upon cessation of PBG, may result in contamination of the breathed oxygen. If so, this would pose a health hazard to the individual.

Descriptors :   *BACTERIA, *CONTAMINATION, *PROTECTIVE MASKS, *PRESSURE BREATHING, RISK, HAZARDS, HEALTH, PILOTS, OXYGEN, TOLERANCE, CONTAMINANTS, PRESSURIZATION, RESPIRATION, INFLATABLE STRUCTURES, LOOPS, MASKS, MICROBIOLOGY, HELMETS, BLADDERS, OXYGEN EQUIPMENT, FACE(ANATOMY), SKULL.

Subject Categories : Stress Physiology
      Life Support Systems

Distribution Statement : APPROVED FOR PUBLIC RELEASE