CAW National Council 4000
Occupational Health and Safety

Hazardous Substances:  Carbon Monoxide

Carbon monoxide can create ill-health effects if inhaled.

Short-Term Effects

Exposure to carbon monoxide decreases the ability of the blood to carry oxygen to the tissues. Inhalation of carbon monoxide may
cause headache, nausea, dizziness, weakness, rapid breathing, unconsciousness, and death. High concentrations may be rapidly
fatal without producing significant warning symptoms. Pregnant women are more susceptible to the effects of carbon monoxide
exposure. The effects are also more severe in people who are working hard and in people who are working in places where the
temperature is high or at altitudes above 700 metres.

Long-Term Effects

Exposure to this gas may aggravate heart disease and artery disease and may cause chest pain in those with pre-existing heart


Enclose process
Local exhaust ventilation
General dilution ventilation
Personal protective equipment.


ACGIH TLV 25 ppm (29 mg/m3).

Source:  CAW Health, Safety & Environment Department