Unflued gas heaters and your health
Advice
22 September 2016
Heating provides warmth and comfort during winter, especially for people living in colder climates.
However, unflued gas heaters release polluting gases directly into the room that can potentially harm your health.
This information is for householders and operators of schools, aged care facilities, and other community facilities on the health risks of unflued gas heaters and ways to avoid or reduce those risks.
What is an unflued heater?
An unflued gas heater burns gas to produce heat and has no flue or chimney to carry the combustion products outside or away. Some are portable and are plugged into a gas outlet through a wall or floor socket with a flexible hose, or may be LPG cabinet heaters. Others may be fixed to the wall.
Patio heaters are another type of unflued gas heater. This type of heater should never be used indoors.
What air pollutants do unflued gas heaters produce?
Unflued gas heaters produce a number of pollutants as a result of combustion. Pollutants that can harm your health include nitrogen dioxide and carbon monoxide.
Unflued gas heaters also produce water vapour that can indirectly affect health by increasing the growth of moulds and dust mites.
The amount of air pollutants an unflued gas heater will produce can vary depending on:
- the type of heater
- the way the heater is installed
- how you use the heater
- how often the heater is serviced.
In addition, the level of air pollutants in the room will vary depending on:
- the way you use the heater
- the size of the area you are heating
- how effectively ventilation removes pollutants from the area.
What are the potential health effects of air pollutants?
Unflued gas heaters increase the level of indoor air pollutants and also the incidence of respiratory problems amongst some people in the building.
Health effects from nitrogen dioxide and carbon monoxide may occur immediately at the time of exposure or they may occur sometime later.
Some people are more susceptible than others and may be more likely to suffer adverse effects.
For example, there is a high rate of childhood asthma in Australia and New Zealand, and so care needs to be taken in the choice of heater, particularly where children or the elderly are involved.
Nitrogen dioxide is odourless and invisible at levels that may harm your health. People with asthma are particularly susceptible to the effects of nitrogen dioxide and may experience symptoms more often when using or exposed to an unflued gas heater.
As well, children may experience increased coughing, wheezing and shortness of breath, and may get respiratory infections more often, when they are exposed to unflued gas heaters.
Carbon monoxide is a also invisible and has no odour or taste. It deprives the body of oxygen, leading to impaired thinking and reduced alertness.
If the level of carbon monoxide in a room goes above ‘safe levels’ people with heart disease may get chest pain or angina. Smokers with heart disease are particularly at risk. Young children, unborn babies and the elderly may also be affected.
Exposure to very high levels of carbon monoxide can cause carbon monoxide poisoning.
This can affect anyone. Symptoms of carbon monoxide poisoning include tiredness, shortness of breath, headaches, dizziness, nausea, weakness and/or confusion.
Exposure to extremely high levels of carbon monoxide can cause death.
What should I do if I have an unflued gas heater?
There are several things you can do to avoid or reduce your exposure to pollutants from unflued gas heaters:
- The room need to be well ventilated. Keep internal doors and at least one window open to allow fresh air to enter the room. Check that room vents are not blocked
- Never use an unflued gas heater in the room where you sleep, in a bathroom, caravan or tent
- If you do have an unflued gas heater, consider purchasing a Carbon Monoxide alarm from your local hardware store
- Minimise the length of time you use an unflued gas heater
- Make sure you heater is installed by a licensed gas fitter
- Read and follow manufacturer’s instructions for using your heater
- Have your unflued gas heater serviced by a qualified person at least once a year. Heaters that are not in good working order can release higher amounts of pollutants into the air. Do not do any maintenance on an unflued gas heater yourself.
Ventilation:
Workplaces must be ventilated to allow work to be carried out without risk to health and safety. Fresh, clean air should be drawn from outside the workplace, uncontaminated by other sources, and be circulated through the workplace.
Workplaces inside buildings may have natural ventilation, mechanical ventilation such as fans or extraction units, or air-conditioning.
Where used as an effective control measure, natural ventilation should consist of permanent openings, including windows and doors, that:
- in total are the size of at least five per cent of the floor area of the room, and
- are open to the sky, an open covered area or a ventilated adjoining room.
Natural ventilation can be assisted by mechanical ventilation systems and extraction units to enhance the air circulation in the workplace and remove odours. When used as a control measure, an air-conditioning system should:
- provide a comfortable environment in relation to air temperature, humidity and air movement
- prevent the excessive accumulation of odours
- reduce the levels of respiratory by-products, especially carbon dioxide, and other indoor contaminants that may arise from work activities, and
- supply an amount of fresh air to the workplace, exhaust some of the stale air as well as filter and recirculate some of the indoor air.
Enclosed workplaces should be supplied with comfortable rates of air movement usually between 0.1 and 0.2 metres per second.
Air-conditioning and other ventilation systems should be regularly serviced and maintained in accordance with manufacturers’ instructions. Cooling towers that form part of many air-conditioning systems can become home to Legionella bacteria if they are not properly designed and maintained. Exposure to these bacteria can cause the potentially fatal Legionnaire’s disease. Cooling towers should be designed, installed and maintained in accordance with AS/NZS 3666 SET:2011: Air-handling and water systems of buildings.
More information about air quality is available in AS 1668.2–2002: The use of ventilation and air conditioning in buildings: Ventilation design for indoor air contaminant control.
What alternative heating options do I have?
If you are considering buying a heater, consider one that does not produce indoor air pollution, such as:
- flued gas heating or central heating, which carry the pollutants outside
- an electric heater or reverse cycle air conditioner.
For further information contact WorkSafe ACT on 13 22 81 or email WorkSafe@act.gov.au.
This Alert contains information emerging during an investigation by WorkSafe ACT into the mentioned incident at the date of this report. The information contained in this report does not necessarily reflect the final outcome of WorkSafe’s views or proposed actions with respect to this incident. WorkSafe ACT does not warrant the information in this report is complete or up-to date and does not accept any liability to any person for the information in this report, or its use.
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