E2658-CO
Rev 06.04.2021
Carbon Monoxide
Carbon Monoxide is a colorless, odorless, and tasteless gas that is highly toxic.
Synonyms: Carbonous oxide, Carbon (II) oxide, Flue gas, Monoxide.
Chemical formula
CO
Molar weight
28
Relative gas density (to air)
0.97
Conversion
1 ppm = 1.15 mg/m
3
Boiling point
−191.5 °C
Low explosive limit (LEL), % vol. in air
12.5
Upper explosive limit (UEL), % vol. in air
74
Odor
Odorless
Hazards
Highly toxic. Mild poisoning causes lightheadedness,
confusion, headache, dizziness, and flu-like effects.
Larger exposures can lead to toxicity of the CNS and
heart, and death. After acute poisoning, long-term
problems may occur. CO also has negative effects on a
baby if exposed during pregnancy. Chronic exposure to
low levels can lead to depression, confusion, and
memory loss.
Exposure limits
(NIOSH)
TWA
40 mg/m
3
/35 ppm
IDLH
1380 mg/m
3
/1200 ppm
Conversion of ppm to mg/m
3
is calculated for 25°C and 1 atm.
3
