In all households, ensuring safety from invisible threats like carbon monoxide (CO) and nitrogen dioxide (NO2) requires vigilance and proactive measures. These gases pose significant health risks when accumulated within confined spaces, underscoring the necessity for specialised detectors and efficient ventilation systems.Recognising the gravity of these hazards, this article aims to highlight their sources, symptoms, and essential protocols to safeguard against poisoning incidents and maximising your indoor air quality.
Carbon monoxide (CO) and nitrogen dioxide (NO2) are both by-products of incomplete combustion of fuels, resulting from insufficient oxygen presence. CO is a colourless, tasteless, odourless, and non-irritating gas, whereas NO2 presents as reddish-brown with a harsh smell at high concentrations, and may be colourless but still possess a harsh odour at lower concentrations. These gases are commonly generated in most combustion processes, whether natural or man-made.
Causes of carbon monoxide and nitrogen dioxide.
Road transport stands as the primary contributor to atmospheric concentrations of carbon monoxide (CO) and nitrogen dioxide (NO2), albeit witnessing a remarkable reduction of 95% from 1990 to 2019, attributable to the decline in the iron and steel industries.
Within the UK between 1990 and 2019, the aggregate emissions of carbon monoxide into the environment have declined by 79%. Notably, within indoor settings, significant quantities of both gases emanate from oil, gas, or kerosene heaters, as well as malfunctioning gas appliances.
Predominantly, the general public's exposure to CO and NO2 stems from cooking or utilising fuel-burning appliances inadequately installed, faulty, or inappropriately used, coupled with inadequate ventilation. Instances include improperly installed home boilers and inhaling smoke from household fires, leading to potential exposure.
For smokers, cigarettes serve as the primary source of carbon monoxide emissions. Additionally, the use of shisha or hookah pipes may also contribute to exposure. Low concentration exposure of both gases can occur outdoors, stemming from vehicle emissions and industrial processes.
Household appliances that can produce both CO and NO2 include:
- gas cookers and clay ovens
- wood, gas and coal fires
- gas boilers
- gas or paraffin heaters
The use of barbecues, portable generators or camping stoves indoors as well as turning on vehicles or petrol lawn mowers in your garage can also cause a build-up of CO and NO2.
How to protect yourself from carbon monoxide and nitrogen dioxide.
Ensuring the proper maintenance of all cooking and heating appliances utilising fossil fuels, such as gas, oil, and coal, is imperative. Regular servicing by accredited engineers, including those registered with Gas Safe Register (for gas appliances), HETAS (for solid fuel appliances), and OFTEC (for oil appliances), is paramount to uphold safety standards.
Moreover, adequate ventilation is essential during appliance usage. Chimneys and flues should undergo annual cleaning by qualified sweeps to prevent blockages and maintain optimal airflow.
The key to protecting your indoor air quality will always come down to suitable, efficient and effective ventilation. The use of continuous mechanical ventilation will ensure that the internal air is constantly being removed and replaced with fresh air, taking with it any build up of both CO and NO2 gases in the home. A centralised multi room system such as an MVHR or MEV system will give the best protection for the whole home, but installing dMEV units in problem areas such as kitchens, utility rooms and any other room that houses appliances that can produce CO and NO2 will also help to remove these gases before they can travel through your home and build up to problematic levels.
Additionally, fitting audible carbon monoxide and/or nitrogen dioxide alarms meeting British or European Standards (BS Kitemark or EN 50291) is essential for early detection of high gas levels, bolstering safety measures. However, it's important to note that these alarms may not trigger for lower CO or NO2 levels, underscoring the necessity for comprehensive mechanical ventilation and regular appliance servicing as the primary safeguard against exposure.
Check if you have carbon monoxide or nitrogen dioxide poisoning.
Carbon monoxide (CO) gas, being colourless and odourless, poses a challenge in detection within the environment. Upon inhalation, CO infiltrates the bloodstream through the lungs, binding to haemoglobin, the body's oxygen carrier, thereby diminishing oxygen transportation throughout the body.
Brief exposure to small quantities of CO may manifest in symptoms such as headaches, nausea, dizziness, and muscle pain. Higher concentrations can lead to more severe consequences, including movement impairments, confusion, and even fatalities.
Prolonged exposure to low levels of CO can mimic flu-like symptoms, including fatigue, headaches, and memory problems, making it difficult to distinguish from common illnesses.
Similar to CO poisoning, nitrogen dioxide (NO2) poisoning, stemming from toxic exposure to NO2 gas, poses a significant threat to health. Easily absorbed through the lungs, NO2 inhalation can result in heart failure and, in severe cases, fatalities. Prolonged exposure to NO2, even at lower levels, may induce persistent headaches and nausea.
Symptoms of both CO and NO2 poisoning typically subside upon cessation of exposure, unless severe acute poisoning has occurred.
Symptoms of carbon monoxide or nitrogen dioxide poisoning include:
- headache
- feeling weak/tired
- dizziness
- shortness of breath/cough
- feeling sick or being sick
- confusion
- Irritation to eyes, nose, throat, and lungs
- chest and muscle pain
What to do if you think you have CO or NO2 poisoning?
In the event of suspected carbon monoxide (CO) or nitrogen dioxide (NO2) poisoning, immediate action is essential:
- Cease the use of any appliances suspected of emitting the gases, such as boilers, cookers, or heaters, if feasible.
- Increase ventilation by opening windows and doors to facilitate the inflow of fresh air.
- Relocate outdoors.
- Seek prompt medical advice, refraining from re-entering the affected premises until receiving guidance.
For urgent assistance regarding potential gas leaks, contact the free National Gas Helpline immediately on 0800 111 999. This service operates 24/7.
If a CO or NO2 alarm is triggered or a leak is suspected:
- Discontinue the use of all appliances and evacuate the property promptly, maintaining calmness to avoid exacerbating the situation.
- Report the incident by dialling the National Gas Emergency Service number on 0800 111 999 or the Health and Safety Executive (HSE) Gas Safety Advice Line on 0800 300 363.
- Refrain from re-entering the property and await instructions from emergency services.
- Seek immediate medical assistance.
Should you experience symptoms of CO or NO2 exposure and feel unwell, contact NHS 111, your GP, or in emergencies, dial 999. Although symptoms typically alleviate upon removal from the source of exposure, medical consultation remains crucial.