Workplace (Module 4)
CM
The small partial rebreathing of CODue to reduced permeability of the masks, the warm and humid exhaled breath condenses behind the mask and leads to increases in humidity and temperature. In addition to the breathing resistance of the mask, the material (cotton vs. synthetic) needs to be considered. Although testing on the Sheffield head showed for SM and CM a similar breathing resistance that was lower than that of FFP2, humidity was highest behind the CM during both, exercise and prolonged mask wear, probably due to the higher moisture absorption of cotton (CM) than of the synthetic material (SM).The subjects' perceived physical exertion, especially when wearing the mask for a long time, was probably also influenced by the microclimate, primarily in terms of increased warmth and humidity behind the mask. Similar effects were seen in other studies