A question of safety
Stephanie Trotter, OBE, President & Director of CO-Gas Safety, answers some vital questions around carbon monoxide in buildings.
What is carbon monoxide (CO) and how do we keep ourselves safe from CO and other products of combustion?
CO is a deadly gas that cannot be sensed using human senses. Less than 2% of CO in the air can kill in under three minutes. Firefighters, when talking about CO in smoke (which you can smell), say it takes only three breaths, the first you don’t know there’s a problem, the second you might suspect there’s something wrong but by the third you are unable to take any action.
Where does CO come from?
CO can be emitted from any faulty heating or cooking appliance powered by any carbon based fuel e.g. gas, coal, wood, oil, paper etc. if there is insufficient oxygen at the flame to produce CO2.
Why is CO so lethal?
Because it binds to the haemoglobin in the blood which normally carries oxygen so it suffocates.
What is the difference between CO and CO2?
CO2 consists of one atom of carbon and two of oxygen. CO also contains one atom of carbon but only one atom of oxygen. CO is emitted when there is a lack of oxygen at the flame.
How do you prevent CO in your home?
- Install all cooking and heating appliances correctly according to the manufacturer’s instructions using properly qualified people. With gas, engineers must by law be Gas Safe Registered and qualified to work on your type of gas appliance.
- Maintain appliances regularly according to the manufacturer’s instructions using qualified people.
- As an extra safeguard (e.g.to protect against a bird’s nest falling down the chimney) buy and fit a CO alarm to EN BS50291 from a reputable supplier – NOT the Internet. Get the alarm out of the box and pull the tab to connect the battery.
- Have chimneys and flues swept and checked by a sweep belonging to a recognised trade organisation.
- Ensure adequate ventilation. Do not block grilles which are present to ventilate a fire etc.
Things to consider when building or renovating
The most vital thing to note is where the flue exits the building and where fresh air enters. A family was poisoned by CO when a builder put a conservatory onto the side of a house enclosing the terminal of a gas fire so that all the products of combustion vented into the living space.
It is also vital not to block air grilles put in to provide necessary air to the property.
Integral garages can be dangerous. Keen motor enthusiasts can work on a car while the car engine or other tools are running while fumes seep into the house. A mother committed suicide in a car in an integral garage and the fumes went up into the bedroom above, unintentionally killing one of her children.
All gas cookers and portable gas heaters can emit the products of combustion straight into the living space. For your own sake while working on a building, please use generators placed outside and well away from the building.
Low levels of CO over a long period can make people feel ill but GPs rarely diagnose this as CO
Symptoms of CO poisoning are similar to almost any virus (except no raised temperature) and include headaches, nausea, tiredness, breathlessness and generally feeling unwell and depressed.
Older adults may be at risk of brain damage by low levels well below levels that would trigger a CO alarm
CO-Gas Safety argues that everyone is at risk of low levels with babies and young children particularly at risk because they are smaller.
Do gas engineers test for CO whenever practicable?
Many do but most people are unaware that there is no mandatory duty to do so except possibly indirectly when the manufacturer specifies that this should be done.
But surely if you can afford it, you can obtain a test of the air in your home and the emissions from your carbon fuelled appliances?
Technically this is true but it can be virtually impossible to obtain the services of a Registered Gas Engineer with the qualifications (CMDDA1) and willingness to do this even if the customer knows what to ask for. The cost can be from about £100 to thousands of pounds.
If you agree with CO-Gas Safety that Registered Gas Safe Engineers should test for CO whenever practicable please email office@co-gassafety.co.uk giving your name and email address to be put on our website page on this topic. Please tell us if you are an engineer and if a Gas Safe engineer, please give your Gas Safe Register number. Thank you.
