Effect | Atmospheric Oxygen (dry air, sea level) | |
Concentration % | Pressure mm Hg | |
no symptoms | 16 to 20.9 | 122 to 159 |
increased heart and breathing rate, some lack of coordination, increased breathing volume, impaired attention and thinking | 16 | 122 |
abnormal fatigue upon exertion, emotional upset, faulty coordination, impaired judgment | 14 | 106 |
very poor judgment and coordination, impaired respiration that may cause permanent heart damage, nausea and vomiting | 12 | 91 |
nausea, vomiting, lethargic movements, perhaps unconsciousness, inability to perform vigorous movement or loss of all movement, unconsciousness followed by death | < 10 | < 76 |
convulsions, shortness of breath, cardiac standstill, spasmatic breathing, death in minutes | < 6 | < 46 |
unconsciousness after one or two breaths | < 4 | < 30 |