Carbon monoxide toxicity level information

Atmos Energy Corporation in Jackson, Missouri provided Heartland News with some statistics on the toxicity levels of carbon monoxide poisoning.
PPM CO Time Symptoms
35 PPM 8 hours Maximum exposure allowed by OSHA in the workplace over an eight hour period
200 PPM 2-3 hours Mild headache, fatigue, nausea and dizziness
400 PPM 1-2 hours Serious headache-other syjmptoms intensify.  Life threatening after 3 hours.
800 PPM 45 minutes Dizziness, nausea and convulsions.  Unconscious within 2 hours.  Death within 2-3 hours.
1600 PPM 20 minutes Headache, dizziness nausea.  Death within 1 hour.
3200 PPM 5-10 minutes Headaches, dizziness and nausea.  Death within 1 hour.
6400 PPM 1-2 minutes Headache, dizziness nausea.  Death within 25-30 minutes.
12,800  PPM 1-3 minutes Death