Type III

Within Type III atmospheres, due to either the lack of appropriate levels of atmospheric oxygen, nitrogen, sufficient pressure, the presence of contaminants and/or of trace gases, a breath mask had to be worn. For Humans and most other species, these atmospheres caused immediate or eventual impediments or even incapacitation. Some species could breathe these types of atmospheres depending on physiology, and biology. Planets with a Type III atmosphere sometimes supported native life.