Carbon monoxide (CO) is a colourless, odourless and tasteless gas that mixes with normal air. It remains present for a long time and does not break off spontaneously. Inhaled CO is absorbed into the blood through the lungs, just like oxygen. This disrupts the transport of oxygen to the cells and causes a lack of oxygen.
Carbon dioxide (CO2) is produced during normal combustion of carbon-containing fuels. However, when combustion is incomplete due to a lack of oxygen, carbon monoxide (CO) is formed.
Motor vehicles are an important source of CO. The CO content in the exhaust gases of cars and trucks varies from 0.1 to 8% and in rare cases can even reach 30%. In special circumstances, traffic can lead to serious intoxications, for example in underground car parks from which everyone leaves at the same time after the end of a mass demonstration or in poorly ventilated tunnels where traffic jams occur.
Effect on the human body
Inhaled CO is absorbed into the blood through the lungs, just like oxygen. An important part of this absorbed CO is fixed on the hemoglobin in the red blood cells.
This hemoglobin (dye in the red blood cells) is responsible for the transport of oxygen from the lungs to the cells. The affinity of CO for hemoglobin is 210 to 260 times higher than that of oxygen. Even in the presence of minute amounts, CO will attach to the hemoglobin instead of oxygen. This disrupts the transport of oxygen to the cells and causes a lack of oxygen.
CO is mainly eliminated by exhalation. When the inhalation of CO gas stops, the CO will be progressively exhaled. Administration of oxygen significantly accelerates the elimination of CO. CO intoxication sometimes produces few pronounced symptoms. If one does not consider the possibility of CO intoxication, one can easily miss the diagnosis. It is mainly the circumstances that suggest exposure to CO:
- If someone becomes unwell in a bathroom equipped with a gas water heater.
- If several people in a building complain of headaches, dizziness, nausea and vomiting and these symptoms always occur in the same room and disappear again as soon as they leave that room.
The natural CO content in the ambient air is approximately 0.2 ppm (parts per million). The World Health Organization has established reference values of concentrations and exposure times that are considered harmless to the entire population, including pregnant women and the elderly with (known or unknown) heart and respiratory problems:
- 10 mg/m3 (9 ppm) for 8 hours.
- 30 mg/m3 (26 ppm) for 1 hour.
- 60 mg/m3 (52 ppm) for 30 min.
- 100 mg/m3 (90 ppm) for 15 min.
- Prevent yourself from becoming captivated: never enter a room where an unconscious victim is lying. Call emergency services immediately.
- Ventilate the room, open windows and doors (if you can do this without risking your own safety).
- Call the 112 service and state that it probably concerns CO poisoning. Also be sure to say whether or not the victim is unconscious.
- If possible, switch off the appliances that are suspected to be the cause.
- Evacuate the victim from the room.
- Begin CPR if the victim is no longer breathing
- Further treatment consists of administering oxygen in a high concentration.
The prevention of CO poisoning in parking garages and tunnels is mainly based on the presence of mechanical ventilation. For reasons of energy saving, these mechanical ventilation systems can be linked to a detection system that measures the concentration of CO and NO2.
Sentera offers various solutions for ventilating parking garages. Our SPRKM-R sensors measure the concentration of CO, NO2 and even LPG and can control the mechanical ventilation systems in parking garages. These sensors can be monitored online via Senteraweb and can also generate audible and visual alarms if desired.
For more information about the possibilities that Sentera can offer for your specific projects, you can always contact one of our employees.