The New Straits Times, May 27, 1996
Q: I recently read about a number of deaths involving carbon monoxide gas poisoning. Please tell me more about the sources of the gas, the symptoms of such poisoning and the precautions to be taken?
A: Carbon monoxide (CO) is an odourless, colourless, tasteless gas that is deadly. It is non-irritating and thus can be completely insidious. It is commonly called the "silent killer".
The gas is a by-product of a fuel-burning process when there is an incomplete combustion of any carbon-containing material. This includes cigarette smoke. Under normal circumstance, carbon dioxide (CO2) is formed.
Many fuel-burning heating appliances using kerosene, gas, wood and charcoal such as furnaces, kitchen stoves, hot water heaters, grills, etc, can produce carbon monoxide.
Automobile exhaust fumes too can release the gas, causing environmental pollution.
In areas of massive traffic jams, the level can be dangerously high enough to cause poisoning.
In fact, in recent months, a traffic policeman was reported to be poisoned by the gas while working in the streets of Bangkok.
Death due to CO is caused by the lack of oxygen at the cellular level (cellular hypoxia).
This is because CO can bind 250 times more readily than oxygen to a special blood cell pigment called haemoglobin (forming carboxyhaemoglobin), causing the blood cells to carry and deliver a reduced amount of oxygen in the body.
By replacing oxygen with CO in our blood, our bodies poison themselves by cutting off the needed oxygen to our organs and cells, causing variable damage.
The gas can also disrupt other cellular activities, contributing to the impairment of functions of organs that use large amounts of oxygen like the brain and heart.
Symptoms of CO poisoning mainly relate to these organs. The elderly, children and the unborn are at greater risk.
Thus, when a faulty or unusual condition exists, CO many be vented and in areas where people are present it can cause poisoning and even death.
CO poisoning may be difficult to diagnose because its symptoms are similar to that of flu which includes headache, nausea, fatigue, dizzy spells as well as irregular breathing.
Unlike flu, however, there is no fever associated with the poisoning. The symptoms become more prominent in a closed environment.
Generally any of the above symptoms will subside or disappear if one leaves the affected place or are, and would return if the same place or area is revisited.
This is a good indication that CO could be involved. When symptoms are present, emergency response is normally indicated.
Exposure to low concentration over several hours can be as dangerous as exposure to high levels for a few minutes.
The US Occupational Safety and Health Administration established a minimum safety working level for CO at 35 parts per million (ppm) over an eight-hour period.
The US Environmental Protection Agency has established that residential levels are not to exceed 9 ppm over an eight-hour average.
Evacuation and ventilation of the premise should be done immediately until a safe CO level is reached. Proper equipment and apparatus are necessary to avoid any untoward incidents.
The gas is flammable and can pose a dangerous fire hazard. Severe explosions can occur when it is exposed to heat or flame. Never operate unvented gas-burning appliances in an enclosed are, including leaving the engine of a car running in a garage.
There are a number of clues that could be used in trying to determine whether CO is being released into a particular area.
For example, there may be rusting or water streaking on the vent or chimney; or a loose or disconnected vent pipings; or loose or missing furnace panel.
This may lead to sooting or debris or soot falling from the appliance or vent.
Otherwise there is a unfamiliar or burning odour that could be detected. Other more specific indications would include decreasing supply of heat or hot water, or inability of the appliance to run constantly.
Damage or malfunctioning components in an appliance, hidden blockage or damage in the ventilation system, or other causes leading to improper burning adjustments can also cause excessive CO in a certain area.
However, these may be difficult to detect without some appropriate technical assistance.
Self-servicing or repairs of appliances without proper knowledge and skills as well as tools can also lead to the problem.
This would mean that competent and regular checks on the appliances used are important to avoid any unnecessary hazards, especially in closed compartments or storage areas where the ventilation is poor. Inspectors should check the heating components, thermostat controls and automatic safety devices.
A properly working CO detector could be installed to provide an early warning to consumers when the gas begins to accumulate.
