CO2

250-350ppm

Normal background concentration in outdoor ambient air

350-1,000ppm             

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