Carbon monoxide

The importance of having the gas appliances tested at least annually has been highlighted recently when a caravanner asked if there were any ideas about black sooty marks on the outside of the water heater flue and inside under the seating area along with the smell of fumes.

Without going into the whole technical bits, a caravan which uses Butane or Propane as a fuel source has the very real ability to produce what has become known as " The Silent Killer", or Carbon Monoxide.

Combustion and Carbon Monoxide
When LPG burns, under ideal conditions, it will only produce Carbon Dioxide and Water (H2O), but when used for heating or cooking every appliance will produce some Carbon Monoxide as the flame touches either the heat exchanger or pan base.

Under normal conditions and with appliances in good condition this is usually a very low level and as long as there is adequate ventilation, especially when cooking, there is no need to worry.

The colour of the gas flame is an indicator of how well it is burning the gas.
A nice blue flame with no orange present is perfect combustion,a flame which has yellow or orange in it is not burning all the gas and Carbon Monoxide IS being produced.

Black sooty stains on flue vents or caravan sides or pan bases also is an indicator of poor burning and the production of Carbon Monoxide.

In the event of a problem with any gas appliance, turn it off and seek qualified help befre trying to use again.

The dangers of Carbon Monoxide
Carbon Monoxide KILLS, it does not give a second chance. You cannot see it, smell it or taste it which is why it has been called the "Silent Killler".

The safe levels of presence are laid down in various documents and are expressed as Parts Per Million.
The normal level in everyday life is 0.2ppm.

The MAXIMUM level allowed by Law for human contact is 35ppm in an 8 hour period.

At 400ppm and exposed for 1 to 2 hours it becomes life threatening after approx 3 hours

At 800ppm and exposed for 45 minutes, you are unconcious within 2 hours and with continued exposure, dead within 2 to 3 hours.

At 1600ppm and continued exposed for 20 minutes you are dead within 1 hour

At 3200ppm and continued exposed for 5 to 10 minutes, dead within 1 hour

At 6400ppm, death is within 25 to 30 minutes

At 12800ppm, death is within 1 to 3 minutes.

Staying safe
It is because of the unseen danger that the gas using items should be checked and tested at least every year and whilst I have said that a blue flame is normally no problem, the only real way of being sure is by having a Flue Gas Analysis carried out.
It is also very wise to have a Carbon Monoxide detector in the van.

Before panic sets in, in modern vans all the appliances are Room Sealed which means they draw combustion air in from outside and vent the exhaust to the outside, except the cooker which is why you should provide extra ventilation (open window or door) when cooking.

Another very important point is that vans have fixed ventilation as well as Gas Drop Holes and these should never be covered.

You only get one life... look after it.