What are safe levels of CO and CO2 in rooms?
CO2
| 250-400ppm | Normal background concentration in outdoor ambient air |
| 400-1,000ppm | Concentrations typical of occupied indoor spaces with good air exchange |
| 1,000-2,000ppm | Complaints of drowsiness and poor air. |
| 2,000-5,000 ppm | Headaches, sleepiness and stagnant, stale, stuffy air. Poor concentration, loss of attention, increased heart rate and slight nausea may also be present. |
| 5,000 | Workplace exposure limit (as 8-hour TWA) in most jurisdictions. |
| >40,000 ppm | Exposure may lead to serious oxygen deprivation resulting in permanent brain damage, coma, even death. |
CO
| 9 ppm | CO Max prolonged exposure (ASHRAE standard) |
| 35 ppm | CO Max exposure for 8 hour work day (OSHA) |
| 800 ppm | CO Death within 2 to 3 hours |
| 12,800 ppm | CO Death within 1 to 3 minutes |