How Many People Die From Carbon Monoxide Poisoning?
Accidental carbon monoxide poisoning kills about 29,000 people a year worldwide. The UK and US figures, who is at risk, the symptoms and what alarms do.
Picture a family arriving at a rented holiday cottage on a cold November evening. The heating is old, the windows are shut tight against the wind, and everyone goes to bed early after the long drive. In the morning the parents both wake with pounding headaches and the children say they feel sick. They put it down to a bug, or a bottle of wine, or the travelling. Nobody thinks about the boiler in the cupboard under the stairs.
That is how carbon monoxide works. It has no colour, no smell and no taste. It produces symptoms that feel like flu or a hangover, and it is most dangerous when people are asleep. It is one of the very few causes of death that a cheap plastic alarm on the wall can almost completely prevent.
The headline number
The most detailed global estimate comes from the Global Burden of Disease study, published in The Lancet Public Health in 2023. It found that unintentional carbon monoxide poisoning killed about 28,900 people worldwide in 2021, with an uncertainty range of roughly 21,700 to 32,800.
That works out to around 79 deaths every day. Set against the roughly 170,000 deaths a day shown on our live death counter, it is a small number. But almost every one of those deaths came from a fault, a blocked flue or a generator in the wrong place, which is exactly why it matters.
| Time period | Unintentional CO deaths worldwide (approx.) |
|---|---|
| Per year | 28,900 |
| Per month | 2,410 |
| Per week | 556 |
| Per day | 79 |
| Per hour | 3.3 |
Two important caveats. First, the figure covers accidental poisoning only. Most people who die in house fires are killed by smoke and carbon monoxide rather than flames, but those deaths are counted as fire deaths, which we cover in how many people die in fires every day. Second, in many countries a large share of carbon monoxide deaths are suicides, which are also counted separately. The true number of people killed by the gas is therefore far higher than 28,900.
The good news: deaths have halved
The same GBD study found that the global age-standardised death rate from accidental carbon monoxide poisoning fell by 53.5% between 2000 and 2021. Better appliances, catalytic converters on cars, gas safety laws and cheap alarms have all played a part.
| Finding (GBD 2021) | Figure |
|---|---|
| Deaths in 2021 | About 28,900 |
| Global death rate | 0.37 per 100,000 people |
| Change in age-standardised rate, 2000 to 2021 | Down 53.5% |
| Share of deaths that were male | Almost 70% |
| Age group with the most deaths | 50 to 54 |
| Highest rates | Eastern Europe |
| Share linked to work | About 14% |
Men make up most victims because they are more likely to work with engines, generators and furnaces, and more likely to be working in garages and enclosed spaces. The oldest adults have the highest death rates of all, partly because they are more likely to live with old heating and less likely to notice early symptoms.
Where it kills most
Carbon monoxide deaths follow cold weather and the fuel people burn to stay warm. The GBD study found the highest rates in Eastern Europe, where many homes still rely on coal or wood stoves, and in parts of Central Asia. In East Asia, charcoal used for heating and cooking has long been a problem; South Korea's coal briquette heaters were once a leading cause of accidental death in winter.
| Region or country | Main sources of risk |
|---|---|
| Eastern Europe | Coal and wood stoves, old gas water heaters, poor ventilation |
| Central Asia | Coal heating in homes |
| South Korea and East Asia | Charcoal and coal briquettes, indoor charcoal grills |
| United States | Furnaces, portable generators during power cuts, cars in garages |
| United Kingdom | Faulty gas boilers, blocked flues, barbecues in tents |
| Low-income countries | Cooking with charcoal indoors, often under-recorded |
The last row matters. In many poorer countries carbon monoxide deaths are rarely tested for or written on death certificates, so the global figure is almost certainly an underestimate. Indoor smoke from cooking fires kills millions more through lung and heart disease, which we cover in how many people die from air pollution every day and on our air pollution page.
The United Kingdom
UK deaths from accidental carbon monoxide poisoning have fallen dramatically. A coroner-based study found that the number of accidental, non-fire carbon monoxide deaths in England and Wales fell from 166 in 1979 to 25 in 2012.
| Period | Average accidental non-fire CO deaths per year (England and Wales) |
|---|---|
| 1979 | 166 |
| 2011 to 2015 | About 30 |
| 2017 to 2019 | About 20 |
The fall came from North Sea gas replacing toxic town gas, tighter gas safety rules, the Gas Safe Register and growing use of alarms. Since 1 October 2022, landlords in England must fit a carbon monoxide alarm in any room with a fixed combustion appliance, such as a gas boiler or wood burner (gas cookers are excluded). In Scotland, every home has needed one where there is a carbon fuelled appliance or flue since February 2022.
One UK case did more than any campaign to raise awareness. In 2006, Christi and Bobby Shepherd, aged 7 and 6, died from carbon monoxide from a faulty boiler while on a family holiday in Corfu. Their parents have campaigned ever since for alarms and safety checks in holiday accommodation, which is why many travel safety guides now suggest packing a portable alarm.
The United States
In the United States, the CDC has estimated that accidental, non-fire carbon monoxide poisoning kills around 400 to 500 people a year, with about 15,000 emergency department visits and many more people treated without ever being diagnosed. A CDC review of 1999 to 2012 found an average of 438 deaths a year.
| Measure (US, CDC estimates) | Figure |
|---|---|
| Accidental non-fire CO deaths per year | About 400 to 500 |
| Average deaths per year, 1999 to 2012 | 438 |
| Emergency department visits per year | About 15,000 |
| Deadliest months | December, January and February |
American deaths spike after storms and power cuts, when families run portable generators in garages, basements or just outside windows. Hurricanes, ice storms and the February 2021 Texas winter storm all brought clusters of poisonings. Cars left running in attached garages are another classic cause.
Why it is so deadly
Carbon monoxide binds to haemoglobin in red blood cells more than 200 times more strongly than oxygen. Even low levels in the air gradually push oxygen out of the blood, starving the brain and heart. Because it builds up slowly, people often become too confused or drowsy to act before they realise anything is wrong.
| Carboxyhaemoglobin level in the blood (approx.) | Typical effects |
|---|---|
| Under 10% | Often none; smokers can sit here every day |
| 10% to 20% | Headache, tiredness, mild breathlessness |
| 20% to 30% | Throbbing headache, nausea, dizziness |
| 30% to 40% | Confusion, vomiting, blurred vision, collapse |
| 40% to 60% | Loss of consciousness, seizures |
| Over 60% | Coma and death |
These are rough guides, and children, pregnant women, unborn babies and people with heart or lung disease are affected at lower levels. Survivors of serious poisoning can be left with lasting memory problems, personality changes and movement disorders.
The symptoms people miss
The NHS lists the classic signs as a tension-type headache, dizziness, feeling sick, tiredness and confusion, stomach pain, and shortness of breath. Because those are so ordinary, carbon monoxide is easy to dismiss.
| Clue | What it may mean |
|---|---|
| Several people in the same house feel ill at once | Shared source, not a bug |
| Symptoms ease when you leave the house and return when you come back | The problem is in the building |
| Pets are also lethargic or unwell | Animals are often affected first |
| Symptoms are worse when the heating is on | Faulty boiler, fire or flue |
| Yellow or orange flames on a gas appliance instead of blue | Incomplete burning |
| Soot or brown staining around a fire or boiler | Poor ventilation |
If you suspect carbon monoxide, get outside into fresh air, turn off appliances if it is safe, and call the gas emergency number or emergency services. Seek medical help even if symptoms fade, because a blood test is time sensitive. Some deaths that are put down to people dying peacefully at night turn out to be carbon monoxide, a theme we explore in how many people die in their sleep.
How to stay safe
| Step | Why it works |
|---|---|
| Fit an audible carbon monoxide alarm (BS EN 50291 in the UK) | Sounds before levels become dangerous |
| Put one in every room with a fuel-burning appliance, and near bedrooms | Protects people while they sleep |
| Get gas appliances checked every year by a registered engineer | Catches faults before they leak |
| Sweep chimneys and flues at least once a year | Blocked flues push gas back indoors |
| Never use a generator, barbecue or camping stove indoors or in a tent | The most common cause of avoidable deaths |
| Never leave a car running in a garage, even with the door open | Fumes collect fast |
| Test alarms monthly and replace them when they expire | Sensors wear out, usually after 5 to 10 years |
A good alarm costs less than a takeaway meal. Few other safety purchases have such a clear link between a small cost and a life saved.
Carbon monoxide and seasonal deaths
Carbon monoxide is one of the reasons cold months are more dangerous than warm ones. Heating systems that sat idle all summer are switched on, windows are kept shut, and people spend far more time indoors. It forms one strand of a bigger story we cover in why winter kills more people than summer.
If you want to put this risk in context, our risk calculator and what are the odds of dying from everyday causes show how it compares with other dangers. Headaches are also one of the early signs in a very different condition, covered in how many people die from brain tumours every year.
If you are struggling and having thoughts of ending your life, please talk to someone now. In the UK and Ireland you can call Samaritans free on 116 123, and in the US you can call or text 988. You can read more on our suicide data page.
While you were reading
In the eleven minutes it took to read this article, probably one person somewhere in the world died from accidental carbon monoxide poisoning, and around 1,300 people died from all causes. Most carbon monoxide deaths are completely preventable. You can watch the global count in real time or see today's running total.
Sources: GBD 2021 Carbon Monoxide Collaborators, The Lancet Public Health, 2023; US Centers for Disease Control and Prevention, carbon monoxide poisoning surveillance and MMWR reports; Office for National Statistics, deaths from carbon monoxide poisoning; UK Cross-Government Group on Gas Safety and Carbon Monoxide Awareness; NHS, carbon monoxide poisoning; GOV.UK, Smoke and Carbon Monoxide Alarm (Amendment) Regulations 2022; Scottish Government, fire and smoke alarm guidance. Figures are rounded and estimates vary between sources and years. This article is for general information only and is not medical or safety advice. If you think you have been exposed to carbon monoxide, get to fresh air and seek medical help immediately.
You might also like
How Many People Die in Motorcycle Accidents Every Year?
Around 250,000 motorcyclists die on the world's roads each year. Global, Asian, US and UK figures, risk per mile versus cars, and what helmets do.
How Many People Die From Allergies Every Year
Fatal allergic reactions are rare: about 20 to 40 UK deaths a year and around 200 in the US. Food, drugs, stings, who is at risk and what saves lives.
How Many People Die From Brain Tumours Every Year?
Brain and nervous system cancers kill about 248,500 people a year, around 680 a day. Global, UK and US figures, glioblastoma, children and survival.