Carbon Monoxide Safety In Your Caravan

Carbon monoxide is the one hazard in a caravan that can kill you in your sleep without a single warning sign. It is colourless, it is odourless, and by the time you feel unwell it may already be too late to act. This guide explains what carbon monoxide is, where it comes from in and around your van, the symptoms to watch for, and the simple rules and gear that keep you safe.

What Carbon Monoxide Is and Why It Is Dangerous

Carbon monoxide, written as CO, is a gas produced whenever a carbon-based fuel burns without enough oxygen to burn cleanly. Petrol, diesel, LPG, wood and charcoal all produce it when combustion is incomplete. In the open air it disperses harmlessly. Inside the sealed box that is a caravan, it can build to lethal levels in a matter of minutes.

What makes carbon monoxide so dangerous is that you cannot detect it with your own senses. It has no colour, no smell and no taste. There is no smoke to see, no fumes to cough on, nothing to wake you. You can be sitting in a comfortable, quiet van with no idea that the air around you is turning toxic.

The harm comes from what it does to your blood. Carbon monoxide binds to the haemoglobin in your red blood cells hundreds of times more readily than oxygen does, and once it takes hold it does not let go easily. Your blood keeps circulating but it stops carrying the oxygen your brain and heart need. That is why the classic danger is falling asleep and simply not waking up. Your body never gets the signal that anything is wrong.

Where It Comes From In and Around Your Van

Carbon monoxide is not some rare freak event. It comes from ordinary gear that plenty of travellers carry and use every day. Knowing the sources is half the battle.

Unflued Portable Gas Heaters

This is the big one. A portable LPG heater, the kind with a gas bottle clipped to the back, has no flue to vent its exhaust outside. Every bit of what it burns goes straight into your living space. As it runs it consumes the oxygen in the van, and as the oxygen level drops the flame burns less cleanly and produces more carbon monoxide. In a closed van overnight this is a genuinely deadly combination.

Gas Cookers Used for Heat

Firing up the cooktop or a portable gas ring to take the chill off is a habit that has killed people. A cooker is designed for short bursts with the range hood running and a window open, not for hours of unattended heating in a sealed van. Used that way it becomes an unflued heater by another name, with all the same risks.

Generators or a Running Vehicle Near Vents

A petrol generator puts out serious quantities of carbon monoxide. Park one under the van, beside an open window, or near a floor vent, and the exhaust is drawn straight into your living space even though the machine itself is technically outside. The same goes for leaving your tow vehicle idling close to the van while you sleep, or for a neighbour’s generator running a couple of metres from your open hopper window in a packed camp.

A Leaking or Blocked Heater Exhaust

A properly installed diesel heater is safe precisely because its combustion is sealed and its exhaust vents outside. That safety depends entirely on the exhaust staying intact and clear. A cracked exhaust pipe, a loose joint under the floor, or an outlet that has been blocked by mud, snow or a badly chosen mounting position can let combustion gases find their way back into the cabin. This is the one way a diesel heater can turn dangerous, and it is entirely preventable with a good install and the occasional check.

The Symptoms of Carbon Monoxide Poisoning

The cruel part of carbon monoxide poisoning is that the early symptoms are vague and easy to blame on something else. People put them down to a long drive, a big day, a poor night’s sleep or a cold coming on, and carry on breathing the same air.

Early signs to take seriously include:

• Headache, often dull and across the forehead, is usually the first sign.
• Dizziness or light-headedness, especially when you stand up.
• Nausea and sometimes vomiting.
• Tiredness and confusion, a heavy, foggy feeling that makes it hard to think clearly or act.
• Shortness of breath on mild exertion.

A telling clue is that everyone in the van feels off at once, and pets do too. If two people wake with the same headache, or the dog is unusually sluggish, treat it as a warning. As exposure continues the symptoms worsen towards vision problems, loss of coordination, collapse and unconsciousness. If you suspect carbon monoxide, get everyone out into fresh air immediately, open the van right up, and call 000. Do not go back inside to investigate until the air has cleared.

The Golden Rules

You do not need to be an expert to stay safe. A handful of firm rules covers almost every real-world scenario.

• Never run an unflued gas heater in a closed van overnight. If you rely on portable gas for warmth, use it only while you are awake, with a window and a roof vent open, and turn it off before you sleep. Better still, heat with a sealed, flued diesel heater instead.
• Never use a gas cooktop as a heater. Cook with ventilation, and switch the gas off when the meal is done.
• Never run a generator near windows, vents or under the van. Site it well away from the van and downwind, and never leave one running overnight close to where people are sleeping, yours or a neighbour’s.
• Keep your tow vehicle from idling beside the van when people are inside and windows are open.
• Keep heater exhausts sealed and clear. Check the exhaust pipe and joints on a flued heater periodically, make sure the outlet is not blocked or buried, and have any exhaust smell or odd running looked at straight away.
• Ventilate. The factory vents in your van are there for a reason. Do not tape them over to stop draughts. A little airflow is what stops any stray combustion gas from concentrating.

Fitting and Testing a Carbon Monoxide Alarm

Every rule above is worth following, but human beings forget, gear fails, and the whole point of carbon monoxide is that you cannot sense it yourself. That is why an alarm is not optional. It is the one piece of safety equipment that will actually wake you when something goes wrong in the night.

A CO Alarm Is Not a Smoke Alarm

This trips a lot of people up. A smoke alarm detects particles of smoke. It will not detect carbon monoxide at all, and carbon monoxide produces no smoke. They are two completely different devices sensing two completely different things. Your van needs both: a smoke alarm for fire, and a separate carbon monoxide alarm for CO. Fitting one does nothing to cover the other.

Choose a Marine or RV-Rated Unit

Buy a carbon monoxide alarm that is specifically rated for marine or recreational vehicle use rather than a basic household unit. The reason is simple: a van vibrates constantly on rough roads, swings through big temperature ranges, and lives in humidity a suburban hallway never sees. Marine and RV-rated alarms are built to keep working through all of that. A cheap home unit may rattle itself into failure or false alarms within a season. Look for one that carries a recognised standard and states clearly that it is suitable for caravans, motorhomes or boats.

Where to Mount It

Carbon monoxide mixes fairly evenly with air rather than sinking or rising sharply, so mounting height is less critical than placement. Fit the alarm in or near the sleeping area, at roughly seated or lying head height, so it protects you where you are most vulnerable. Keep it a sensible distance from the cooktop and from the heater outlet to avoid nuisance alarms, and do not tuck it away in a cupboard or behind a curtain where airflow cannot reach the sensor.

Test It, and Mind Its Age

An alarm you never check is a gamble. Press the test button regularly, weekly is ideal and the start of every trip is the minimum. Keep the battery fresh, or choose a sealed unit with a long-life battery. Carbon monoxide sensors also wear out: most units have a stated life of five to seven years and a replace-by date printed on the back. When that date arrives, replace the whole unit. An expired sensor may look fine and still fail to alarm when it counts.