Public schools in NSW are being forced to heat classrooms with unflued gas heaters under the school building program, although health warnings that emissions from the heaters pose a risk to asthmatic children and can trigger respiratory problems.

The heaters, which produce a potentially poisonous mixture of nitrogen dioxide, carbon monoxide, carbon dioxide and formaldehyde, are being phased out of schools in all states, except NSW and Queensland.

According to the NSW government, the new-model unflued gas heaters comply with National Environment Protection Measures and are safe to use when rooms are ventilated.

The Australian, however can confirm the standards, developed by the National Environment Protection Council (NEPC), relate only to ambient air quality, outdoors. The NEPC does not test indoor air quality, nor does it check emissions from these appliances.

Concerns about the unflued gas heaters have surfaced at the Bungendore Public School, 40km east of Canberra, where more than 10 per cent of students are registered asthmatics.

Bungendore's P&C president Sharon Baxter-Judge said, This is simply not acceptable. It's like driving a car into a classroom and leaving it on. The same poisons come out.

They tell us we should just open the windows or doors. But in the middle of winter, it's 5C outside, and I though the reason you turn the heaters on is to stay warm.

According to a commonwealth health report of July 2007 entitled The health effects of unflued gas heater use in Australia, exposure to unflued gas heaters causes increased respiratory symptoms in children with asthma, and it is also related with new asthma in children.

Recognizing the potential dangers, the NSW government's Health Department stated on its web site that if gas is your preferred heating fuel, purchase a flued heater.

However, at a meeting with Angus Dawson, BER program director in NSW on April 9, the school was told it was not allowed to do so, because the Education Department policy dictated the use of unflued gas heaters where gas was available.