A comparison of the ventilatory responses to wearing either a hood or a mask escape respirator with identical nose-cups.

Differences in escape respirator design can influence the wearer's ventilatory response and impact inspired oxygen (O2) and carbon dioxide (CO2) concentrations. There has been minimal investigation into the differences between hood and mask designs as escape respirators that compare between the ventilatory responses of wearing either a hood or mask escape respirator with an identical nose-cup. Thirty-nine healthy young males participated in the study. Each subject participated in two 20-min sessions of monitored breathing, wearing either a hood-type filtering facepiece respirator "CAPS 2000" (Shalon Chemical Industries, Israel & Supergum Industries Ltd, Israel) or an "Orange Diamond" filtering facepiece mask-type escape respirator (DEA Mop, Israel). Inspired gas concentrations of CO2 and O2 as well as the ventilatory response were recorded through a nose-cup during the test. Inspired CO2, minute ventilation, breathing frequency, and the index of central ventilatory drive (VT/TI) were all significantly higher (p < 0.05) while wearing a mask respirator compared to a hood respirator. The hood respirator evaluated in the present study outperformed the mask respirator in most indices when measured at rest. The hood respirator had a reduced ventilatory demand compared to the mask respirator and may be advantageous for individuals with weaker respiratory systems, such as the elderly or those who suffer from respiratory diseases.