Friday, September 6, 2013

Carbon monoxide in the workplace

Is Carbon Monoxide (CO) in your Workplace?

Does Carbon Monoxide exist in your workplace?  If so, to what extend is it a problem?  Do you know the legal limits of exposure?  What controls do you have in place? 

Webster’s Dictionary definition of Carbon Monoxide:

“Carbon monoxide”, with the chemical formula CO, is a colorless and odorless, tasteless, yet highly toxic gas.  Its molecules consist of one carbon atom covalently bonded to one oxygen atom. There are two covalent bonds and a coordinate covalent bond between the oxygen and carbon atoms. 

Carbon Monoxide is produced from the partial oxidation of carbon-containing compounds, notably in internal-combustion engines. Carbon Monoxide forms in preference to the more usual carbon dioxide when there is a reduced availability of oxygen present during the combustion process. Carbon monoxide has significant fuel value, burning in air with a characteristic blue flame, producing carbon dioxide. Despite its serious toxicity, CO plays a highly useful role in modern technology, being a precursor to myriad products.” 

Carbon Monoxide is known as the “Silent Killer”.  Carbon Monoxide poses extreme danger because there is no warning of its presence.  Over exposure poses the hazard that must be addressed through controls set in place in the workplace. ** Pregnant workers should be removed from exposure and consult a physician if exposed.  Lethal dose concentration effects are adversely impacted by such factors as:  

Ø  An individual’s age

Ø  An individual’s health

Ø  If an individual smokes

Ø  If an individual performs physically demanding work

Ø  Where working in high temperatures or high altitudes 

Carbon Monoxide is inhaled, passing through the body to the lungs and into the bloodstream preventing the ability of blood to transport oxygen to vital tissues in our body.  This process is called Chemical asphyxiation.  Lethal dose exposure limits and symptoms according to Health Canada and OHSA are: 

Ø  Exposure Limit Maximum:  8 hours per day = 25 parts/million (ppm) for healthy adults 

Even low levels of exposure over prolonged or repeated exposure will affect alertness, perception, memory, personality, moods, and performance of fine motor skills.  These health effects may eventually impact safety performance standards in the workplace. 

Identified below are a few of the sources of Carbon Monoxide at a worksite are:

Ø  Kilns, furnaces and boilers,

Ø  Welding

Ø  Space heaters, oil and gas burners

Ø  Cigarette smoke

Ø  Internal combustion engines

Ø  Moulding of plastics

Ø  Forging, ceramic, petroleum, steel and waste management processes

Ø  Fire and explosions

Ø  Small gas powered engines and tools i.e. floor buffers, concrete cutting saws, high-pressure washers

Ø  Propane forklifts

Ø  Ice resurfacing equipment (Zamboni)

Ø  Exposure to methylene chloride (dichloromethane) used for degreasing and paint stripping

Work areas are defined as “Open Spaces” or “Confined Spaces”.  Open spaces i.e. outdoors (lawns) and indoors where carbon monoxide produced from equipment such as gas powered trimmers, other equipment and cars would dissipate as fresh air is generated by movement of air (wind) or internal air circulation systems and/or a person’s movement, preventing the build-up of carbon monoxide. 

Confined spaces are spaces with low air flow restricted, i.e. tanks, bins, hoppers and vaults, where there is higher risk of an increased concentration (build-up) of Carbon Monoxide, therefore increasing the risk of exposure. The OHSA Regulation defines a confined space as follows:

"confined space", except as otherwise determined by Inspectors or other authorized authorities (fire department etc.), means an area, other than an underground working area, that:
(a) is enclosed or partially enclosed,
(b) is not designed or intended for continuous human occupancy,
(c) has limited or restricted means for entry or exit that may complicate the provision of first aid, evacuation, rescue or other emergency response service, and
(d) is large enough and so configured that a worker could enter to perform assigned work;

Preventing exposure to Carbon Monoxide is “Best Practice”, however if this is not possible, sources of Carbon Monoxide must be controlled to prevent exposure by:

Ø  Use of engineering controls – mechanical processes used to eliminate exposure to Carbon Monoxide that would remove the substance from the air i.e. ventilation system, air and exhaust systems.

Ø  Changes in work practices to reduce exposure (administrative controls) – education and training of workers, carbon monoxide detectors and inspection/maintenance of engineering controls

Ø  Use of PPE (Personal Protective Equipment) – respiratory protective equipment 

Best Practice includes conducting assessments of your workplace, developing a monthly inspection process, policies and procedures; assessing each job for exposure limits, assessing each employee (a Medical Surveillance Program – Lung Test, Blood Tests immediately following exposure), assess each piece of equipment that poses a threat of emissions and conducting a facility air quality inspection (typically completed annually) and an Annual Workwell Audit specific to your facility and industry. 

  1. Assess your workplace
  2. Testing – Medical Surveillance, Air Quality, CO tests
  3. Control Hazards – implement controls and modifications
  4. Maintenance, repair and modifications to equipment and facility to address hazards as identified.
  5. Ongoing monthly inspections and pre-use inspections
  6. Annual assessments/testing
  7. Educate -Employee Training

In our homes, Carbon Monoxide may be produced in lethal quantities in automobile exhaust, faulty home heating systems, improperly used portable gas stoves and heaters, and improperly vented wood stoves and fireplaces.  Safety does not stop at work!

Lynne Bard, BA (Honours), C.H.R.P., CES
Human Resources, Safety & Risk Management Experts
Taking the Complexity out of Compliance
Beyond Rewards Inc.
Phone: 519-821-7440

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