There could be more deaths and injuries from carbon monoxide poisoning than official figures show, according to research.
The BBC has been told that although Health and Safety Executive (HSE) figures report a decline over the last decade, the actual incidents could be higher as nurses do not always test for the poisoning.
Carbon monoxide is produced when fuel does not burn properly. The colourless, tasteless and odourless gas leaks from boilers, flues or gas appliances that have not been maintained or installed properly.
Official HSE figures suggest that four people died and 117 fell ill following carbon monoxide poisoning in the home during the year up to June 2010. In 2009, 17 people died and 86 became ill.
But research from the Gas Safety Trust charity, which has been examined by 5 Live Investigates, suggests that the true figure could be much higher.
The HSE has also accepted that there was underreporting in all health and safety matters.
To complete the study, the charity examined a pilot involving London-based ambulance crews who went out with five carbon monoxide testing kits over a 12-month period.
During the trial they found 83 people suffering from poisoning in London alone, which is almost as many as the official figures for Britain as a whole in 2008-09.
Teams in Leeds, Birmingham and Manchester will now also take part in the pilot, with the charity warning that official figures will “skyrocket” if London’s results are replicated across the country.