Accession Number:

ADA265221

Title:

Characterization of Chemical Defense Mask Breathing Resistance Tolerances

Descriptive Note:

Final rept. May 1991-Jan 1992

Corporate Author:

KRUG LIFE SCIENCES SAN ANTONIO TX SAN ANTONIO DIV

Report Date:

1993-03-01

Pagination or Media Count:

37.0

Abstract:

The purpose of this study was to evaluate the effects of wearing MCU- 2P and M-17 groundcrew chemical defense masks during steady-state work. Five MCU-2P mask configurations MC were tested mask without filter MCU-OF, mask 1 filter MCU-1F, mask 2 filters MCU-2F, mask 1 filter air blower A MCU-ABA, and mask 1 filter air blower B MCU-ABB. Ten subjects walked on a treadmill 3 mph - 5.0 grade for 1 hr wearing each MC. Variables measured included inspiratory and expiratory mask cavity pressures IMCP and EMCP, mask cavity pressure-swing MCPS, peak inspiratory airflow rate PIAFR, respiratory rate RR, peak tidal volume PTV, minute volume MV, heart rate HR, rating of perceived exertion RPE, perceived inspiratory and expiratory effort PIE and PEE, and overall breathing discomfort OBD. Each MC was characterized by a significantly different IMCP. The MCU-ABA produced the lowest IMCP, while MCU-1F produced the highest. MCU-2F reduced inspiratory resistance by about 47. There were no significant differences in PIAFR, RR, PTV, MV, RPE, PIE, PEE, and OBD among the various MC. The new MCU-2P mask does not improve total breathing resistance over the standard M-17 mask. Neither mask should induce significant cardiorespiratory strain providing the physical work is of low intensity. A very effective but logistically difficult approach to reduce the level of inspiratory resistance imposed by the MCU-2P mask is to provide powered ventilation as compared to the relatively simple installation of a second filter.... Breathing resistance, Protective mask, Exercise, Ventilation, Perceived effort.

Subject Categories:

  • Anatomy and Physiology
  • Logistics, Military Facilities and Supplies
  • Chemical, Biological and Radiological Warfare
  • Protective Equipment

Distribution Statement:

APPROVED FOR PUBLIC RELEASE