| Carbon monoxide content of inhaled air (%) |
Physiological effects |
| 0.020 |
Possible mild frontal headache after two to three hours |
| 0.040 |
Frontal headache and nausea after one to two hours; occipital
(rear of head) headache after 2.5 to 3.5 hours. |
| 0.080 |
Headache, dizziness, and nausea in 45 min; collapse and possible
unconsciousness in who hours. |
| 0.160 |
Headache, dizziness, and nausea inn 45 min; collapse and
possible unconsciousness in two hours. |
| 0.320 |
Headache and dizziness in 5 to 10 min; unconsciousness and
danger of death in 30 min. |
| 0.640 |
Headache and dizziness in 1 to 2 min; unconsciousness and danger
of death in 10 to 15 min. |
| 1.280 |
Immediate physiological effect; unconsciousness and danger of
death in 1 to 3 min. |