Carbon monoxide (CO): risks, legal aspects, gas detection...

Carbon monoxide poisoning happens after a person has inhaled this gas. The effects of poisoning vary depending on the quantity of carbon monoxide in the air, the length of time during which the person is exposed to the gas, and the person’s state of health and sensitivity to the effects of the gas.

Symptoms

The symptoms of carbon monoxide poisoning are often difficult to recognise because they are very similar to the symptoms of other health problems. There is a suspicion of carbon monoxide poisoning when:

•     One or more people are in a place where there is a source of carbon monoxide
•     Those people have symptoms
•     The symptoms are alleviated or disappear completely when the people leave the place in question

The most common initial symptoms are: headaches, fatigue, nausea, sickness. In more severe cases of poisoning, the symptoms are: dizziness, chest pain, vision problems, concentration difficulties. And in very severe cases, the symptoms include movement coordination problems and muscle paralysis preventing the person from leaving the place, and loss of consciousness. The severity of the poisoning depends on the amount of CO-bound haemoglobin.

Treatments

You must seek medical attention to treat carbon monoxide poisoning.

Treatment usually consists in the administration of oxygen in high concentration. If the person is in a more serious condition, the doctor may prescribe treatment in a hyperbaric chamber. This involves placing the person in a closed facility in which they receive pressurised oxygen.
Precautions to be taken to counter the risk of carbon monoxide poisoning

To avoid the risks of carbon monoxide poisoning, Sante Publique France recommends that you:

•     Have heating and hot water production systems and chimney ducts systematically inspected and serviced by a qualified professional every year before winter
•     Open the windows or doors for at least 10 minutes every day and keep ventilation systems in good working order, never obstructing the air vents
•     Never leave temporary heaters switched on all day
•     Place cooking appliances (fire baskets, barbecues) and power generators outside of buildings
•     Comply with the user guides provided with heating and cooking appliances

Despite all of the above, if symptoms of carbon monoxide poisoning are observed in several people in the same room, it is vital to ventilate the room, get everyone outside and call an ambulance.

86% of cases of carbon monoxide poisoning happen in the home. In houses and flats, the main sources of CO are: wood or gas stoves and fireplaces, heating appliances that use natural gas, propane, kerosine, etc.

What the law says about periodic inspections of heating installations

The purpose of this law is to prevent atmospheric pollution. It transposes European Directive no. 2015/2193 on the limitation of emissions of certain pollutants into the air, including carbon monoxide (CO), sulphur dioxide (SO₂), nitrogen oxides (NOx) and dust. This law only concerns central heating appliances such as boilers. There is currently no legal obligation to service individual appliances such as bathroom water heaters, gas or oil stoves. However, such appliances must comply with the standards in force, and be serviced in line with the manufacturer’s recommendations.

We also know that the build-up of CO is one of the risk factors involved in carbon monoxide poisoning. It is the result of the burned gases released by these appliances, because combustion is never 100% efficient. But this build-up is due to improper use or inadequate servicing of household appliances, which strongly increases the amount of CO in the air. That is why it is so important to have boilers inspected and serviced every year to guarantee that both people and the equipment are safe. You need to check the entire automatic shutdown process, from gas detection to transmission of the signal through to closure of the gas supply.

See the article: Boiler room regulations: important dates to ensure conformity with the decree of 3 August 2018

Regulations in places of worship

Often caused by improper use of heating systems, cases of collective carbon monoxide poisoning in places of worship are more common than you might think. In addition to having aging installations, these buildings are not always properly ventilated, meaning carbon monoxide may form and build up more easily.

Preventing these accidents is based on simple advice. It is just as important to have a properly functioning ventilation system as to service your heating appliances.

• The person in charge of the place of worship must therefore make sure that the heating appliances are serviced on a regular basis, and check that the ventilation systems are in good working order.
• It is recommended not to use combustion heaters except during the celebration or cultural event, within the time limits recommended by the manufacturer.
• Gas radiant panels are prohibited except when people are present (current regulations ban their use to pre-warm the building); there are even plans to ban the use of these appliances in buildings that are open to the public.
• In addition, it is recommended that all heating appliances be used in conjunction with a fixed carbon monoxide detector, or failing that, a portable detector.

    In addition to publishing and reminding people of this advice, the purpose of the instruction is to distribute the four informational sheets below (ref. appendix 1) to the mayors of towns and villages, so that they can raise awareness among the players concerned and give appropriate prevention advice about the risks of CO poisoning to the people in charge of places of worship:

1.     Regulations applicable to places of worship;
2.     Behaviour to adopt in the presence of people showing clinical signs of poisoning;
3.     Behaviour to adopt if a carbon monoxide detector warning is triggered;
4.     Monitoring data.

Source (french): https://solidarites-sante.gouv.fr/fichiers/bo/2006/06-09/a0090025.htm

There are two types of detection: portable gas detection and fixed gas detection.

Portable gas detection is used by firefighters tackling fires, for example, because high levels of CO are always released during forest fires and fires that occur in buildings, etc. The detector warns the person carrying it that there is a potential danger, because the CO level may increase up to the upper explosive limit, meaning that an explosion may occur when the door to the building on fire is opened.

In addition to portable detectors, firefighters carry a HbCO kit in their medical bags. This is an accessory used to measure the amount of carbon monoxide in the air exhaled by a victim. The kits include a holder, a single-use mouthpiece, a long tube connecting the mouthpiece to the holder (the exhaled air lands directly on the sensor) and a short delivery tube. Firefighters ask the victim to hold their breath for at least 20 seconds before blowing all the air in their lungs into the mouthpiece. Meanwhile, the firefighters keep the holder in place to ensure the detector and the holder are not in direct contact.

Fixed gas detection is more commonly used in closed areas such as boiler rooms, car parks and tunnels. Carbon monoxide sensors are installed in strategic places so that any gas can be detected. If the rate becomes abnormally high, a signal is transmitted to the gas controller until the gas supply is shut off by the solenoid valves. This signal may be combined with a visual and/or audible warning to warn the people present that they must evacuate the closed area as quickly as possible.