Whereas Australia has had national standards and goals set for key pollutants in outdoor (i.e. ambient) air, there are no standards or guidelines for pollutant levels in indoor air. There are regulations and codes that address indoor air quality, but (with the exception of regulations dealing with gas heating appliances) these apply to workplaces and to commercial premises and public buildings, rather than to residential dwellings.¹⁵² Despite these limitations, Australian governments have actively sought to improve indoor air quality through a range of interventions (both regulatory and nonregulatory) targeting environmental tobacco smoke and unflued gas heaters.

In the case of environmental tobacco smoke (also known as passive smoking), powers to control smoking in public places lie mostly with state and territory governments. All states and territories prohibit smoking in cinemas and theatres (originally motivated by concern over risk of fire), in most types of public transport and in areas where food is prepared. Over the past decade or so, most jurisdictions have extended such prohibitions to cover cars carrying children and a wide variety of public places, including government buildings, airports, premises where food is consumed, pubs and nightclubs, and shopping centres. Increasingly, similar bans are being applied to various outdoor public spaces. States and territories have also used occupational health and safety legislation to require smoke-free work environments.¹⁹⁸

As noted in Section 3.2.3, there is concern about the impact of unflued gas heaters on indoor air quality and therefore health. Although these heaters are primarily known as a source of nitrogen dioxide, they also produce carbon monoxide and formaldehyde. Unflued gas heaters are regulated in all states and territories. Although the regulations vary between jurisdictions, they all require compliance with Australian standards AS 4553-2000 (AG 103-2000): Gas space heating appliances, and AS 5601-2002 (AG 601-2002): Gas installations.¹⁹⁹ However, as various studies have shown, conformity with the Australian standards does not guarantee that levels of nitrogen dioxide will not adversely affect health.^167-168

In New South Wales, longstanding public concern over the use of unflued low-NO_x gas heaters in schools led the government to commission a major independent review of respiratory health effects on children exposed to such heaters. The review, by the Woolcock Institute of Medical Research, found that, although exposure to these heaters was not linked to significant reductions in lung function, it did cause an increase in respiratory symptoms, especially in children with a predisposition towards developing allergic reactions. The review concluded that ‘it is important to seek alternative sources of heating that do not have adverse effects on health’.²⁰⁰ In response, the New South Wales Minister for Education and Training announced in July 2010 that the use of unflued heaters would be phased out in all New South Wales public schools.²⁰¹