Yoda: Masks are Hazardous to Your Health

Text below fold. Clarification of OSHA’s requirement for breathing air to have at least 19.5 percent oxygen content. Human beings must breathe oxygen . . . to survive, and begin to suffer adverse health effects when the oxygen level of their breathing air drops below [19.5 percent oxygen]. Below 19.5 percent oxygen . . . … Continue reading Yoda: Masks are Hazardous to Your Health