CO Home Safety Ltd

Carbon Monoxide Effects of Cumulative CO Exposure

CO Parts per million (ppm) Inhalation time (approx) and symptoms developed 
35ppm The maximum allowable concentration for continuous exposure in any 8 hr period according to HSE
150ppm Slight headache after 1 ½ hrs
200ppm Slight headache, fatigue, dizziness, nausea after2-3 hrs
400ppm Frontal headache within 1-2 hrs, life threatening after 3 hrs
800ppm Dizziness, nausea and convulsions within 45 minutes. Unconsciousness within 2 hrs. Death within 2-3 hrs
1600ppm Headache, dizziness and nausea within 20 minutes. Death within  1hr
3200ppm Headache, dizziness and nausea within 5-10 minutes. Death within 25-30 minutes
6400ppm Headache, dizziness and nausea within 1-2 minutes. Death within 10-15 minutes
12800ppm Death within 1-3 minutes