Carbon monoxide

Carbon monoxide is an odourless gas produced as an emission in combustion processes.


Exposure to carbon monoxide mainly occurs through inhalation.

Where possible you should not do tasks or use plant that generates carbon monoxide.

If you must work where there is a risk of exposure to carbon monoxide you must:

  • use ventilation
  • isolate high exposure tasks
  • install gas detectors either in work areas or as personal alarm systems
  • follow the plant manufacturers instructions for maintenance and use
  • inspect plant regularly
  • use supplied air respirators where required
  • train workers to fit, use and maintain PPE
  • always follow the advice in safety data sheets and on product labels.

In the event of suspected exposure, call the Poisons Information Centre on 131 126


Carbon monoxide is released through incomplete combustion processes including combustion of fossil fuels. For example, vehicle and plant emissions (like forklifts and generators), gas appliances (stoves, space heaters, water heaters, furnaces and LPG operated floor polishers and cleaners) and burning charcoal, plastic and wood.

Occupations that are most at risk of exposure to carbon monoxide include:

  • cooks and bakers
  • blast furnace and boiler room workers
  • diesel engine operators
  • garage mechanics
  • brewery workers
  • pulp and paper workers
  • fire fighters
  • glass manufacturers
  • coal miners.

Any work conducted in enclosed or restricted spaces poses a higher risk of exposure to carbon monoxide as the chemical will accumulate in the area. Work in areas such as trenches, garages and plant rooms should only be conducted after assessing the risk of carbon monoxide exposure. Use of plant powered by combustion engines should be minimised in such restricted areas where ventilation is not adequate.


Exposure to carbon monoxide occurs through inhalation. Carbon monoxide displaces oxygen in the blood stream resulting in less oxygen reaching tissues including the heart and brain.

Short term (acute) exposures to carbon monoxide can result in:

  • dizziness
  • nausea
  • fatigue
  • muscular weakness
  • impaired judgement
  • unconsciousness.

While removing a worker from the carbon monoxide contaminated atmosphere usually results in complete recovery, the severity of symptoms and outcomes in largely dependent on the overall health of the worker. Delayed neurological effects may also be observed days to months after exposure, characterised by personality and behavioural changes, dementia, depression and muscular shakes. Short term exposure to high levels of carbon monoxide can result in death due to a lack of oxygen reaching vital organs (including brain and heart).

Long term (chronic) exposure to carbon monoxide may cause:

  • headaches
  • irritability
  • insomnia
  • foetal changes in pregnant workers (including miscarriage)
  • personality disturbances
  • decreased exercise tolerance
  • impaired judgement (including when driving).

More information

Read the carbon monoxide technical fact sheet.

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