Carbon monoxide in air

Carbon monoxide is taken up by blood much more readily than oxygen is, so relatively small amounts of it in inhaled air can affect our health. Prolonged exposure to carbon monoxide can cause tissue damage. People suffering from cardiovascular disease are particularly at risk.

What is carbon monoxide?

Carbon monoxide is a colourless and odourless gas. It is found in smoke and is formed from the incomplete combustion of fuels such as peat, wood, coal, charcoal, natural gas, petrol, kerosene, oil, or propane.

Carbon monoxide is also found in exhaust fumes from cars, petrol and gas engines, gas ovens and cooktops, generators, lanterns, BBQ’s and gas and wood heaters.

What are the health effects of carbon monoxide exposure?

When breathed in, carbon monoxide displaces oxygen in the blood and deprives the heart, brain and other vital organs of oxygen. Carbon monoxide may cause “flu-like” symptoms such as headache and tiredness, progressing to dizziness, confusion, nausea or fainting. Very high amounts of carbon monoxide in the body may result in oxygen deprivation, leading to loss of consciousness or death.

Who is most at risk?

Whether someone develops health effects from exposure to carbon monoxide depends on a number of factors including:

  • the levels of carbon monoxide in the environment (from smoke and also other environmental sources)
  • how long a person is exposed
  • a person’s individual susceptibility, for example, having an existing heart or lung condition; having anaemia; being young, elderly or pregnant (the unborn child)
  • the level of exercise or physical activity, which increases the amount of air breathed into the lungs (ie breathing rate)
  • other lifestyle factors such as being a smoker.

How much carbon monoxide do we detect in Victoria?

Carbon monoxide levels have been consistently below standards in recent years and existing controls appear to be adequate.

Carbon monoxide air quality categories

The carbon monoxide (CO) data on our website will be shown in different colours, depending on the amount of CO in the air. The categories range from green – when levels of CO are low and air quality is very good – through to black – when high levels of CO result in very poor air quality.

Air quality category CO ppm
Very good 0–2.9
Good 3.0–5.8
Fair 5.9–8.9
Poor 9.0–13.4
Very poor 13.5 or greater

Page last updated on 27 Mar 2018