Carbon Monoxide - The Silent Killer


Carbon Monoxide (also known as CO) is a colourless, odourless poisonous gas and is a common yet preventable cause of death from poisoning worldwide.  Carbon monoxide (CO) is produced as a result of incomplete burning of carbon-containing fuels.  Exposure to CO reduces the blood's ability to carry oxygen.

Carbon monoxide exposures especially affect unborn babies, infants, and people with anaemia or a history of heart or respiratory disease.

Breathing low levels of CO can cause fatigue and increase chest pain in people with chronic heart disease. Breathing higher levels of carbon monoxide causes flu-like symptoms such as headaches, dizziness, and weakness in healthy people.  Carbon monoxide also causes sleepiness, nausea, vomiting, confusion, and disorientation.  At very high levels, it causes loss of consciousness and death.

CO poisoning is responsible for over 40 deaths per year in Ireland.  Many occur at home as a result of house-fires.  Thousands of others become ill or seek medical attention.  All too often people with CO poisoning ignore the warning symptoms, which can be fatal.

How might carbon monoxide enter my body?

 

Carbon monoxide will enter your body if you breathe in contaminated air.  Carbon monoxide is quickly absorbed into the bloodstream from the lungs.  Then it combines with haemoglobin in your blood to form carboxyhaemoglobin.  This reduces the ability of your blood to carry oxygen around your body and it robs the heart, brain and other vital organs of oxygen.

 

What effect would carbon monoxide have on my health?

 

The effect depends on how much of the gas you are exposed to and how long you are exposed.  Carbon monoxide poisoning can be reversed if it is caught in time. Long term exposure to low levels of carbon monoxide may produce heart disease and damage to the nervous system.  Carbon monoxide is a category 1 reproductive toxin. This means that the substance is known to be toxic for human reproduction - exposure of pregnant women to carbon monoxide may cause reductions in birth weight, cardiomegaly (enlarged heart), delays in behaviour development in neonates and nervous system damage to children.

 

The level of carbon monoxide normally present in the air we breathe is unlikely to cause ill effect.

 

Occupations which may be at risk of exposure to carbon monoxide include:

 

  • Welder
  • Garage mechanic
  • Fire-fighter
  • Organic chemical synthesiser
  • Metal oxide reducer
  • Docks worker
  • Diesel engine operator
  • Forklift operator
  • Marine terminal worker
  • Toll booth or tunnel attendant
  • Customs inspector
  • Police officer
  • Taxi driver

 

What are the signs of carbon monoxide exposure?

 

The signs or symptoms of carbon monoxide exposure copy many common illnesses and can easily be confused with flu or simple tiredness.  At low levels, carbon monoxide exposure may cause poor concentration, memory and vision problems, and loss of muscle coordination.  At higher levels, it may cause headaches, fatigue, vomiting and nausea.  At very high levels, the symptoms intensify and it can kill within a matter of hours.

Symptoms of CO Poisoning

Symptoms of Carbon Monoxide poisoning can be similar to those caused by other illnesses such as a cold or flu. They include:

  • Unexplained headaches, chest pains or muscular weakness
  • Sickness, diarrhoea or stomach pains
  • Sudden dizziness when standing up
  • General lethargy

What to Do

To reduce the chances of CO poisoning in your workplace, you should take the following actions:

 

  • Install an effective ventilation system that will remove CO from work areas.
  • Ensure existing vents are unblocked.
  • Maintain equipment and appliances (e.g. water heaters, space heaters, cookers) that can produce CO in good working order to promote their safe operation and to reduce CO formation.
  • Consider switching from petrol/diesel-powered equipment to equipment powered by electricity, batteries, or compressed air if it can be used safely.
  • Prohibit the use of petrol/diesel-powered engines or tools in poorly ventilated areas.
  • Provide personal CO monitors with audible alarms if potential exposure to CO exists.
  • Test air regularly in areas where CO may be present, including confined spaces.  Provide appropriate Personal Protective Equipment.
  • Inform and train staff on the dangers of CO.
  • Install a monitoring system with an audible CO alarm to alert staff.
  • Ensure that hazard warning labels are placed on all tolls/equipment likely to produce CO.

 

What legislation is applicable to carbon monoxide?

 

  • Safety, Health and Welfare at Work Act, 2005 (No. 10 of 2005)
  • Safety, Health and Welfare at Work (Chemical Agents) Regulations, 2001 (S.I. No. 619 of 2001)
  • Safety, Health and Welfare at Work (General Application) Regulations, 2007 (S.I. No. 299 of 2007)
  • Safety, Health and Welfare at Work (Confined Spaces) Regulations, 2001 (S.I. No. 218 of 2001)

 

The OELV (Occupational Exposure Limit Value) can be found in the 2007 Code of Practice for the Safety, Health and Welfare at Work (Chemical Agents) Regulations, 2001.