Carbon monoxide kills around 40 people in the UK every year and sends hundreds more to hospital. It has no colour, no smell, and no taste — which is exactly what makes it so deadly.
What Is Carbon Monoxide?
Carbon monoxide (CO) is a colourless, odourless, tasteless gas produced by the incomplete combustion of carbon-based fuels — gas, oil, wood, and coal. When these fuels burn properly, they produce carbon dioxide (CO2), which is harmless in normal concentrations. When combustion is incomplete — because of a faulty appliance, poor ventilation, or a blocked flue — carbon monoxide is produced instead.
Because you can't detect it without a specialist alarm, CO poisoning often occurs during sleep. By the time symptoms appear, the victim may be too incapacitated to escape.
Where Does Carbon Monoxide Come From?
Any appliance that burns fuel can produce CO if it malfunctions or isn't properly maintained:
- Gas boilers — The most common source in UK homes. A cracked heat exchanger or blocked flue can cause CO to leak into the property.
- Gas cookers and hobs — Particularly if burners are left on without igniting
- Open fires and wood-burning stoves — A blocked or inadequately swept chimney prevents CO from escaping
- Oil and LPG heaters
- Portable generators — Never use indoors or in a garage
- Car engines — Never run a car engine in an enclosed garage
Symptoms of Carbon Monoxide Poisoning
Low-level CO poisoning is often mistaken for flu or a viral illness — without the high temperature. Symptoms include:
- Headache
- Dizziness and confusion
- Nausea and vomiting
- Shortness of breath
- Feeling unwell only when at home (symptoms clear when you go outside)
- Multiple people in the household feeling ill simultaneously
Is a Carbon Monoxide Alarm a Legal Requirement?
Under the Smoke and Carbon Monoxide Alarm (Amendment) Regulations 2022, all landlords in England must install a CO alarm in any room that contains a fixed combustion appliance (excluding gas cookers). This includes gas boilers, gas fires, and solid fuel burners.
Even if you're an owner-occupier, we strongly recommend fitting CO alarms near every fuel-burning appliance and on every floor. The cost of an alarm is minimal compared to the risk.
What to Do If Your CO Alarm Sounds
If your CO alarm activates: get everyone out of the building immediately, leave doors open as you go, do not re-enter the property, call the Gas Emergency Service on 0800 111 999, and seek medical attention even if you feel well.
Security Red Alert installs combined fire and CO alarm systems across London, ensuring your property meets all current regulations. Contact us for a free survey.
Need help with this in London?
Security Red Alert covers all 32 London boroughs from our Summerstown SW17 office. Explore our Fire Alarm Installation, Home Fire Alarms and Fire Extinguishers services, or call 020 8946 5567 for a free survey.