If you have been poisoned by carbon monoxide because a landlord, employer or premises occupier failed to maintain gas appliances or provide adequate ventilation, you can claim compensation. Landlords must arrange annual gas safety checks under the Gas Safety (Installation and Use) Regulations 1998. CO poisoning can cause lasting brain damage and neurological problems. You normally have three years from diagnosis or date of knowledge to bring a claim.
Carbon monoxide (CO) is an odourless, colourless gas produced when fuels burn incompletely. Faulty boilers, gas fires, cookers and flues are the most common sources. Because you cannot see, smell or taste CO, poisoning often goes undetected until serious harm has been done. Symptoms mimic flu — headaches, nausea, fatigue — and low-level exposure over weeks or months can cause lasting neurological damage. If your poisoning was caused by someone else's failure to maintain appliances or comply with gas safety regulations, you have the right to claim.
Who is liable?
- Landlords. Under the Gas Safety (Installation and Use) Regulations 1998, private landlords must have all gas appliances, fittings and flues checked annually by a Gas Safe registered engineer and provide tenants with a copy of the gas safety record within 28 days. Failure is a criminal offence and, in a civil claim, strong evidence of breach of duty.
- Employers. Under the Health and Safety at Work etc. Act 1974 and the gas safety regulations, employers must ensure gas appliances in the workplace are properly maintained and ventilation is adequate.
- Occupiers of public premises. Hotels, holiday lets, restaurants and other commercial premises must maintain their gas installations safely. The Occupiers' Liability Act 1957 and gas safety regulations apply.
- Negligent gas engineers. A Gas Safe registered engineer who carried out a faulty installation or inspection may be personally liable.
Health effects of CO poisoning
The severity of CO poisoning depends on the level and duration of exposure:
| Exposure level | Typical effects |
|---|---|
| Low-level, short-term | Headache, dizziness, nausea, fatigue — often mistaken for flu |
| Moderate, prolonged | Confusion, memory problems, chest pain, shortness of breath |
| High-level or acute | Loss of consciousness, seizures, cardiac arrest, death |
| Chronic low-level (weeks/months) | Persistent neurological problems, cognitive impairment, depression, personality changes |
Delayed neurological effects can appear days or weeks after acute exposure, even after initial recovery. This is why medical monitoring and prompt diagnosis are critical.
How much compensation?
Compensation depends on the severity and lasting effects of the poisoning. The Judicial College Guidelines (JCG), 17th edition (April 2024), value the injury by its nature. CO poisoning claims may engage several JCG chapters depending on the harm — typically the psychiatric injury and/or brain injury brackets:
| Outcome | Guideline bracket |
|---|---|
| Mild poisoning, full recovery within weeks | £1,900 – £4,350 |
| Moderate symptoms lasting months, some residual effects | £4,670 – £14,720 |
| Serious neurological effects with lasting cognitive impairment | £48,000 – £166,500 |
| Very severe brain damage | £344,150 – £493,000 |
Special damages for lost earnings, ongoing care, rehabilitation and treatment are added. In cases of permanent brain damage, the lifetime care and lost earnings components can be very substantial. See brain injury claims and how compensation works.
Evidence for a CO poisoning claim
- Blood or breath test for carboxyhaemoglobin (COHb). This is the most direct evidence of CO exposure, but levels drop quickly after removal from the source, so early testing is vital.
- Medical records including A&E attendance, GP visits and any neurological or neuropsychological assessment.
- Gas safety records — or evidence that no annual check was done.
- Gas Safe engineer's inspection report identifying the fault.
- CO alarm data if a detector was present and recorded levels.
- HSE or local authority investigation report if the incident was reported.
- Records of financial losses — lost earnings, treatment costs, care.
✓ CO is often initially misdiagnosed
Because CO symptoms mimic flu, food poisoning and other common conditions, many cases are initially misdiagnosed. If your symptoms improve when you leave the building and return when you go back, that is a strong indicator of CO exposure. Mention this pattern to your doctor and request a COHb blood test.
Time limits
You have three years from diagnosis or from the date of knowledge — when you first became aware your symptoms were caused by CO exposure (Limitation Act 1980, section 14). See our time limits guide.
Getting help
We are not a law firm. For a solicitor experienced in CO poisoning or housing disrepair claims, use the SRA register or the Law Society "Find a Solicitor" service. Gas Safe Register can confirm whether an engineer is registered, and Citizens Advice can help with tenants' rights.
Frequently asked questions
Can I claim compensation for carbon monoxide poisoning?
Yes, if your CO poisoning was caused by another party's negligence. Common defendants include landlords who failed to maintain gas appliances or arrange annual gas safety checks, employers who exposed you to CO at work, and the occupier or manager of premises with faulty heating or cooking equipment. You need to show the responsible party breached a duty of care and that breach caused your poisoning.
What are a landlord's duties for gas safety?
Under the Gas Safety (Installation and Use) Regulations 1998, landlords must have all gas appliances, fittings and flues checked annually by a Gas Safe registered engineer and provide tenants with a copy of the gas safety certificate within 28 days of the check. Failure to do so is a criminal offence and, if a tenant is poisoned as a result, strong evidence of negligence for a civil claim.
How long do I have to claim for CO poisoning?
Three years from the date you were diagnosed with carbon monoxide poisoning, or from the date you first became aware your symptoms were caused by CO exposure, whichever is later (Limitation Act 1980 section 14). CO poisoning is often misdiagnosed initially because the symptoms mimic flu and other conditions, so the date-of-knowledge rule is important.
What are the symptoms of carbon monoxide poisoning?
Symptoms include headaches, dizziness, nausea, confusion, breathlessness and fatigue. Prolonged or high-level exposure can cause loss of consciousness, seizures, brain damage and death. CO is odourless and colourless, so victims often do not realise they are being poisoned. A key clue is if symptoms improve when you leave the building and return when you come back.
Can I claim if I was poisoned in a holiday rental or hotel?
Yes. The owner or operator of holiday accommodation, including hotels, Airbnbs and holiday lets, has a duty to maintain gas appliances safely and provide adequate ventilation. If faulty equipment in holiday accommodation caused your CO poisoning, you can claim against the owner or operator.
How much compensation for carbon monoxide poisoning?
It depends on the severity of the poisoning and any lasting effects. Mild poisoning with a full recovery may attract several thousand pounds. Moderate cases with prolonged symptoms can be worth significantly more. Where CO exposure causes permanent brain damage, the general damages element alone can be very substantial, with special damages for ongoing care, lost earnings and treatment added on top.
Get help from official, free sources
- Solicitors Regulation Authority (SRA) — check a solicitor is regulated
- Gas Safe Register — check an engineer is registered
- HSE — gas safety guidance
- Citizens Advice — tenants' rights and guidance
Related guides: brain injury claims, holiday accident claims, accident at work claims, how to make a claim and no win, no fee explained.