Flueless gas action

The UK Government has announced a series of proposals to improve indoor air quality by reducing pollution from flueless gas appliances such as gas cookers, water heaters and flueless gas fires.

The UK Government has announced a series of proposals to improve indoor air quality by reducing pollution from flueless gas appliances such as gas cookers, water heaters and flueless gas fires.

New research, published today, suggests that under certain conditions, levels of some pollutants in homes may exceed outdoor air quality standards.

There is no immediate danger to users of these appliances, but certain pollutants are undesirable and the Government will now take action to reduce the concentrations released from these appliances.

To assuage the situation, the Government will push for an amendment of European standards for gas appliances to ensure reduced emissions of certain pollutants from flueless appliances as well as the amendment of UK Installation Standards to ensure concentrations of these pollutants are reduced.

It also intends to work with British Standards Institute to ensure national standards and building regulations on safe installation of flueless combustion appliances reflect innovation in appliance and installation practice and reinforce advice to the public on the safe use of flueless gas appliances.

The research, commissioned by the DTI and HSE, tested a range of appliances under laboratory conditions. Tests were often carried out under ’worst case’ conditions: with reduced ventilation, extended periods of operation and with safety devices disarmed.

The highest concentrations of carbon monoxide seen in the tests were considerably below the levels that could cause fatalities and did not exceed the outdoor air quality standards in most of the tests. The few exceptions were generally attributable to the abnormal operating conditions.

The air quality standard for nitrogen dioxide was exceeded in several of the tests. This could result in a worsening of the condition of those with asthma similar to other triggers such as cold air, exercise and colds. Asthmatics who consider they are affected can use their ’reliever’ inhaler in the usual way to lessen the symptoms. Healthy people are unlikely to be affected.

There is no outdoor air quality standard for nitrogen monoxide. However, the Health and Safety Executive recently issued advice that the average concentration of nitrogen monoxide in the workplace should not exceed 1000 ppb, averaged over an eight hour working day. Levels in excess of this were measured in some of the tests. The Department of Health will be producing a leaflet for the public later this year explaining the possible health effects and what action the public can take to reduce exposure.


Two research reports measuring concentrations of combustion products released from flueless gas appliances have been published in HSE’s contract research series, accessible electronically <link>here=http://www.hse.gov.uk/research/rrhtm/index.htm</link>.

The reports are:

RR23 – Flueless gas appliances – concentrations of carbon monoxide, carbon dioxide and nitrogen dioxide, and particulate level produced in use prepared by Advantica Technologies Limited.

RR127- Measurement and modelling of combustion products from flueless gas appliances prepared by BRE Environment.

The Committee on the Medical Effects of Air Pollutants (COMEAP) statement ’Assessment of the Health Implications of Concentrations of Nitrogen Dioxide and Carbon Monoxide Indoors – Advice to HSE and DTI’ is available <link>here=http://www.advisorybodies.doh.gov.uk</link>.

The possible effects of carbon monoxide are much more serious than those of nitrogen dioxide or nitrogen monoxide. Carbon monoxide can cause coma and death at high concentrations. These lethal concentrations were not reached in any of the tests.

However, the EPAQS air quality standard of 10 ppm eight hour running average (see <link>here=http://www.defra.gov.uk/environment/airquality/aqs/co/index.htm</link>) was exceeded to a certain extent during tests involving excessive use of a cooker oven and use of a gas fire with a faulty pilot light. These test results reinforce the importance of advice to use appliances in accordance with the manufacturer’s instructions and to ensure that they are regularly serviced.

The EPAQS report on nitrogen dioxide is available <link>here=http://www.defra.gov.uk/environment/airquality/aqs/no2/index.htm</link>.

HSE has issued guidance on the health effects of nitrogen monoxide and advice on workplace control measures, available on HSE’s website <link>here=http://www.hse.gov.uk/pubns/chan28.htm</link>.

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