CARBON MONOXIDE IN THE WORKPLACE
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365-BSA-01-IMOT © 2024, Workplace Safety & Prevention Services (WSPS)
1 877 494 WSPS (9777) | 905 614 1400 | WSPS.CA
Do not attempt to put out a fire involving carbon monoxide unless the flow of gas can be stopped
because a more explosive mixture of gas and air may form. To reach the valve to shut off the flow of gas,
use a carbon dioxide or dry chemical extinguisher. Use a water spray to keep the area cool and to
prevent ignition of other materials. Do not use a water jet.
Carbon monoxide is chemically reactive at temperatures over 90 °C. This reactivity and chemical
incompatibility can be of great concern in laboratories and process operations where compressed
carbon monoxide is present (see Table 2 below).
Table 2: Incompatibility of Materials
Materials to avoid:
Metal oxides (e.g., iron oxide, nickel oxide) – reduced to lower metal oxides, metals or metal carbides
at elevated temperatures
Some heavy metals (e.g., nickel, iron, chromium) – formation of explosive metal carbonyls
Alkali and alkaline earth metals (e.g., sodium, potassium, magnesium) – react to produce salts
Aluminum powder – ignition can occur
Iodine heptafluoride – ignition can occur
Sulfur – carbon monoxide reacts slowly with the liquid and rapidly with the vapour to give carbonyl
sulfide
Chlorine – can form phosgene in the presence of light or a charcoal catalyst
Bromine – can form carbonyl bromide in the presence of light or a charcoal catalyst
Bromine trifluoride, bromine pentafluoride, chlorine dioxide or peroxodisulfuryl difluoride – react
explosively
Oxidizing materials – increased risk of fire and explosion
Carbon monoxide has no odour, taste, or colour, and it is also non-irritating. Pure carbon monoxide
provides no warning about its presence. But in many circumstances, carbon monoxide is present in
combustion products or exhaust gases which are themselves irritating. Where carbon monoxide may be
produced or present, steps must be taken to prevent overexposure.
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