We are often asked about the effects of carbon dioxide on the body and how to tell if there is a gas leak. As a result of this, we have created this post to provide additional information about exposure to carbon dioxide.
What is carbon dioxide?
Carbon dioxide (CO2) is a gas which occurs naturally in the Earth’s atmosphere at a rate of 400 parts per million (ppm). It is colourless, odourless and non-flammable.
CO2 is used in a wide range of industries:
- it is used to carbonate soft drinks and alcoholic beverages,
- it is a primary ingredient in fire extinguishers
- it is used to decaffeinate coffee and clean clothes.
- it is used to promote growth in fruit and vegetables
- it is used as a coolant gas in power stations
- carbon dioxide can also be generated by certain products, for example, when timber is held in a confined space, it undergoes oxidation which causes CO2 to be produced.
The level of CO2 normally in the atmosphere is harmless, but an increase of levels of the gas in a working or home environment can have serious health effects. Some organisations have set long and short term exposure limits for working, and this legislation varies globally. OSHA (Occupational Safety and Health Administration) have set an exposure limit of 5,000ppm over an eight-hour period, and 30,000ppm over a 10-minute period, whilst the European standard EH40 has set a short-term 15-minute exposure limit of 15,000ppm.
How can different levels of carbon dioxide affect me?
- 0.04% (400ppm) – this is the normal level of carbon dioxide in the atmosphere
- 1 – 1.5% (10,000 – 15,000ppm) – slight effect on chemical metabolism after exposure of several hours
- 3% – (30,000ppm) – carbon dioxide is weakly narcotic at this level, resulting in deeper breathing, reduced hearing, headaches and an increase in blood pressure and pulse rate
- 4-5% (40,000ppm – 50,000ppm) – breathing becomes deeper and more rapid. Signs of intoxication becomes more evident after 30 minutes exposure
- 5-10% (50,000ppm – 100,000ppm) – breathing becomes more laborious with headache and loss of judgement
- >10% (100,000ppm) – when CO2 concentration increases above 10%, unconsciousness will occur in less than one minute. Unless prompt action is taken, further exposure will eventually result in death
Physiological effects of carbon dioxide
Physiological effects of carbon dioxide include:
- Reduced hearing
- Mild narcosis
- Increased heart rate and blood pressure
- Shortness of breath
- Dimmed sight
The benefits of a carbon dioxide monitor
As CO2 has no taste or smell, it can be hard to detect. This is why CO2 monitors are so important, and a workplace risk assessment may suggest that gas detectors are installed.
As CO2 is heavier than air, it is recommended that fixed carbon dioxide detectors are not mounted at head height – for example, we recommend that the Ax60 is wall-mounted 450mm off the ground and the repeater unit is placed at head height at the entrance to the room.