A neighbour's quick thinking after her carbon monoxide alarm sounded saved a family's lives, following a potentially deadly carbon monoxide (CO) leak in the middle of the night.

As reported in last week’s Romford Recorder, the family of three – a man, a woman in her 20s and a baby believed to be about 15 months old – were taken to hospital from their flat in Elm Park near Romford after upstairs neighbour Pauline Smith raised the alarm when her FireAngel CO alarm alerted her to the gas’ presence.

Firefighters said she had saved the day. “The carbon monoxide detector undoubtedly saved this family’s lives,” commented Hornchurch Fire Station watch manager Darren Draper. “If the neighbour had not raised the alarm this incident could have been a lot worse.”

It is believed a faulty cooker may have caused the leak. Carbon monoxide levels in the flat were dangerously high. Ms Smith told the Recorder: “My window was open but the alarm was still going off, so I thought I’d better call the National Grid.”

An engineer came and checked Ms Smith’s house, but found no fault with her cooker or boiler.

“I told him it must have been coming from downstairs,” Ms Smith explained. “He banged on the door but couldn’t get an answer. I told him to keep trying because there was a baby in there. Next thing I knew, the fire brigade, police and ambulance were outside.”

Firefighters from Hornchurch and Dagenham evacuated seven people from the block and used specialist gas detectors to check the carbon monoxide levels before allowing them back in. Ms Smith had a nasty shock when the fireman found most of the gas was in her bedroom; subsequent tests showed a level of 10% carbon monoxide in her blood.

Draper reiterated: “It is very important that everyone has a carbon monoxide alarm and at least one smoke alarm in their home.”

“Carbon monoxide is a highly poisonous gas that has no colour, taste or smell, so it is totally invisible to the human senses. Because the gas is so difficult to detect and the symptoms (such as headaches) so similar to other complaints, many people can be poisoned without knowing it. Everyone is at risk, but CO is most hazardous for vulnerable groups including the elderly, unborn babies, pregnant mums and children who spend a lot of time at home.

“Badly fitted appliances, which use gas or other household fuels such as coal and wood, along with faulty boilers, flues or poorly ventilated ovens are often to blame. Worryingly, CO can also enter a property from adjoining households, as seen in this case.”

Carbon monoxide is potentially fatal, but exposure to low levels of the gas over just a few hours can be just as lethal as high levels over a short amount of time, causing lasting damage to your health.