The “silent killer” is putting thousands at risk as new data reveals a worrying drop in alarm testing and growing cases of carbon monoxide poisoning.

Authorities are urging households to check and install carbon monoxide detectors after national data revealed that poisoning incidents have doubled since 2020.

Figures from the Devon and Somerset Fire and Rescue Service show that emergency call-outs to suspected CO incidents reached 7,703 in 2025, compared to 3,876 in 2020 - with experts warning that many more cases likely go unreported.

Mike Porter, who leads on CO safety for the National Fire Chiefs Council, said the danger lies in the gas’s invisible nature.

“We can’t taste it, we can't smell it, and we can't see it” he said. An alarm is the only way to know it’s there - and it could save lives.

Around 50 people in the UK die every year from accidental exposure, while thousands more are treated for symptoms including headaches, nausea, dizziness, and breathlessness. Tragically, many of these cases are preventable.

The Summer Risk Few Think About

While many associate poisoning with winter heating, experts warn that the danger doesn’t disappear when the weather warms up. According to SGN, 95% of UK households did not test their carbon monoxide alarms at all in 2024.

Barbecues, pizza ovens, and camping stoves can all be a risk in enclosed spaces - such as tents, caravans, or poorly ventilated patios - creating a year-round hazard.

Dan Edwards, SGN’s Social Impact Programme Lead, said:

“It’s deeply worrying that so many people aren’t testing their carbon monoxide alarms. Carbon monoxide is known as the ‘silent killer’ for a reason - it’s invisible, it’s odourless, and it can be deadly. Having an alarm is essential, but it’s just as important to test it regularly to make sure it works."

Rising Cases and Missed Maintenance

Experts believe the cost-of-living crisis has also contributed to the rise in cases, as households delay appliance servicing or chimney sweeping to cut costs.
Common CO sources include gas and oil boilers, log burners, open fires, and gas hobs - all of which need regular professional checks.

Alarming Gaps in Awareness

A 2025 survey found that:

• An average of 53 people die annually in the UK from accidental CO exposure.
• Deaths from accidental carbon monoxide exposure rose by 39% from 2022 to 2023.
• Carbon monoxide emergency calls in London increased by 37% in 2024.

Campaigners are now calling for greater awareness and accessibility to carbon monoxide safety devices. Through various VCMA-funded programmes, free alarms are being distributed to vulnerable households across the UK.

How to Stay Safe

Simple steps can save lives:

• Have gas, oil, and solid fuel appliances serviced annually by a qualified engineer.
• Keep vents clear and ensure proper ventilation.
• Never use BBQs or portable heaters indoors or in enclosed spaces.
• Install a certified audible alarm - and test it regularly.
• Check the expiry date on your alarm and replace it as needed.

If you suspect a carbon monoxide leak, or if your alarm sounds, open windows immediately, move outside into fresh air, and call the National Gas Emergency Number: 0800 111 999. Testing your alarm once a month takes seconds - but it could save your life.

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