The Effects of Oxygen Deficiency

Oxygen Content (% by Volume) Effects and Symptoms
(At Atmospheric Pressure)
19.5% Minimum permissible oxygen level.
15-19% Decreased ability to workstrenuously. May impair coordinationand may induce early symptoms inpersons with coronary, pulmonary, or circulatory problems
12-14% Respiration increases in exertion, pulse up, impaired coordination, perception, judgement.
10-12% Respiration further increases in rate and depth, poor judgement, lips blue.
8-10% Mental failure, fainting, unconsciousness, ashen face, blueness of lips, nausea, and vomiting.
6-8% 8 minutes, 100% fatal; 6 minutes, 50% fatal; 4-5 minutes, recovery with treatment.
4-6% Coma in 40 seconds, convulsions, respiration ceases, death.These values are approximate and vary as to the individual’s state of health and his physical activities.