This fact sheet provides information on how unflued gas heaters can affect your health, and on how to reduce the potential hazard associated with the use of these appliances.
Heating your home can be essential in winter to provide warmth and comfort, especially for people living in colder climates. If you have an unflued gas heater, there is an indoor air pollution hazard associated with its use that can affect your health.
This fact sheet provides information on how unflued gas heaters can affect your health, and on how to reduce the potential hazard associated with the use of these appliances.
Gas heaters produce heat through burning gas fuel. When gas fuel is burnt, air pollutants and water vapour are also produced.
A flued gas heater vents these air pollutants and water vapour outside the home through a chimney or flue, while an unflued gas heater releases them directly into the home. This means that an unflued gas heater has the potential to cause indoor air pollution in your home that may affect your health.
You will be exposed to higher levels of air pollutants inside your home when using an unflued gas heater. The air pollutants produced by an unflued gas heater that can be harmful to your health include carbon monoxide (CO) and nitrogen dioxide (NO2).
The levels of air pollutants produced by an unflued gas heater can vary depending on:
In addition, the level of air pollutants in the room you are heating can vary depending on:
Water vapour is not regarded as an air pollutant, however, moisture build-up can occur in the room you are heating. This may lead to the growth of moulds and dust mites, which have the potential to affect your health.
Health effects caused by exposure to air pollutants can occur immediately at the time of exposure or be delayed. The effects will also depend on the type and amount of pollutants to which you are exposed. Some people are more susceptible than others and can suffer health effects more easily than others.
Carbon monoxide (CO) is difficult to detect in your home. It is invisible and has no smell or taste. It can cause toxic effects in humans by depriving the body of oxygen, and impairing thinking and reflexes. CO levels will rise in a home where an unflued gas heater is in use.
A poorly installed heater, or a heater in a room with a lack of fresh air, can cause excessive levels of CO, and can lead to CO poisoning. Symptoms of CO poisoning include flu-like symptoms, headache, dizziness, weakness, vomiting, shortness of breath, confusion, blurred vision and loss of consciousness. CO poisoning can lead to death.
People most susceptible to the health effects of CO include those with heart disease, infants, unborn babies and the elderly.
Nitrogen dioxide (NO2) can be difficult to detect in your home. NO2 is an invisible and tasteless gas, however, it does have a strong odour. NO2 levels will rise in a room where an unflued gas heater is in use. Breathing in high levels of NO2 can cause irritation of the respiratory tract and shortness of breath.
People with asthma and other respiratory diseases are particularly susceptible to the effects of exposure to NO2. Children may suffer more often from cold symptoms or asthma attacks if exposed over a prolonged period of time.
There are a number of ways to avoid or reduce exposure to air pollutants from an unflued gas heater.
If you suspect someone has been exposed to carbon monoxide and experiencing adverse health effects please contact Poisons Information Centre, 24 hours a day, 7 days a week on 13 11 26.
For further information you can call 1300 066 055 to talk to your local Public Health Unit.