Measurements of oxygen concentration of air within totally encapsulating chemical-protective suits

This study measured oxygen concentrations of air within totally encapsulating chemical-protective (TECP) suits during simulated hazardous materials emergency response operations. This was done to allow assessment of the suitability of use of air within TECP suits as an emergency air supply during escapes from contaminated areas following loss of primary air supply. Samples of air were extracted through a probe installed in TECP suits while the suits were worn during simulated hazardous materials control operations. Data on oxygen concentration were obtained using direct reading equipment and through Orsat analysis of samples. Results indicate that the air within a TECP suit becomes significantly oxygen-deficient soon after the suit is closed, but generally maintains oxygen concentrations somewhat above those known to produce significant physiological effects. However, due to the further reduction of oxygen content inherent in breathing the air within TECP suits, it is anticipated that symptoms of oxygen deficiency sufficient to impair escape could be experienced in some instances. Recommendations are made for modifying current training practices to better prepare personnel working in Level A chemical-protective ensembles to cope with loss of air supply.