Confined Space Harzards in Toronto

Confined Space Hazards

In the Confined Space Guidelines, page 13, paragraph #3 reads “Note that even if a space might not be a confined space under the regulations, the employer must take every precaution reasonable in the circumstances to protect the workers entering the space.” Even the MoL recognizes there are non regulated confined spaces that have to be addressed.


For years a US TV network has peppered their broadcasting (especially children’s programming time slots) with “the more you know” ads. These ads are to stimulate interest in further education which will enhance the listener’s life. This is true in our business and the best place to start is with the hazards. No matter where you work or what you are doing, it is imperative that a hazard assessment be completed. This assessment enables you not only to understand what will hurt you, but also provide the rationale for the safeguards that are required to protect the worker and the consequences (injuries) that could happen if protection is not in place. This assessment is also required to be passed on to the employee as they have the “right to know” about the hazards they face. The unstated benefit to this right is that the worker will be motivated to use the hazard control systems that are available.


The hazards you look for must be clearly defined (e.g. moving parts/equipment vs. mechanical energy) and have specific acceptable targets. For instance:


◆ temperature can be stated as “hot” or “cold”. But setting a measurable range between 100 C and 370 C makes the assessment specific and measurable.

◆ clutter is defined as “the accumulation of items without order”. However photos and drawings of an acceptable site shows what you mean.


Hazards can occur from what is in the space, what is happening around the space as well as what job is being performed. Some jobs will have inherent hazards. Even the synergetic effect when hazards combine (e.g. pressure and dust) will have to be evaluated. The trick in hazard assessment is ensuring that all the hazards are evaluated similarly within the same company or organization. To accomplish this a written list of clearly defined dangers that includes the acceptable levels of exposure to each hazard is required. A great list will eliminate assumptions made by the experienced journeyman and/or focus the sights of a novice who may otherwise be guided by the fear of the unknown. We’ve had that list for a while and recently updated it. We need to have the second group in someday and finish the exercise by publishing the new list. However the changes are minor and I encourage all to keep using the old one for just a little longer.


Some hazard identification techniques break the operation down into areas or what is know as “contributing factors”. These factors include the worker(s) involved, design and construction, location, function/process that it performs, the substances that the workers may come into contact with, as well as the task and tools involved. There are other techniques used to identify potential hazards. However over the years I’ve just developed a list of things (hazards) that could hurt someone. They are:




Acceleration/Sudden Movement A sudden increase in the speed of an object greater than .25m/sec.
Biological Materials Harmful parasites, bacteria, viruses and/or fungi.
Blocked Pathways Human pathways are restricted by tools, materials or the space design (eg. low ceilings, corners, protrusions or small doorways) to a width of less than .9 m (3′) and/or a height of 2m (6’5″) and/or without a flat walking surface that prevents or slows a person from leaving.
Choices When you must decide between two or more non similar views, objectives/priorities, tools or procedures when completing a task.
Clutter The accumulation of non permanent items without order.
Combustible Loading Materials that will smoulder or burn at or below temperatures of any ignition sources in the space.
Corrosives A material with a pH value below 2 or above 11.5
Electric Current Electricity greater than 50 milliamps moving from point A to B
Energy Waves Invisible energy waves (e.g. ionizing – alpha, beta, gamma, and x rays, as well as non ionizing – UV, infrared, microwaves, laser and radio waves) that can burn or destroy skin tissue.
Engulfment/Entrapment When a free flowing solid or a liquid weighing more than 50 lbs/ft3 surrounds an individual or if a structural form, defect or similar issue could prevent a worker from leaving the space without assistance.
Flammable/Explosive Materials Materials that will rapidly vaporize at atmospheric pressure and most normal temperatures that a larger than normal quantity of heat and a larger than normal volume of gas (as compared to combustible materials) is released during the process.
Gravity Nature’s downward force which will move an unsupported or unrestrained object to a lower level.
Lack of Oxygen When the oxygen of ambient air supply going into the lungs drops below 19.5%
Lack of Planning When our organization, for what ever reason, fails to define the job, look at the issues of the job, allocate sufficient resources to perform the job, adequately communicate job expectations or follow good accountability practices.
Light Extremes When lighting, space design or processes increase or decrease light from 5 watts/m2 (.46 watts/ft2).
Moving Equipment/Parts Spindles, shafts, gears, belts, arms, pulleys, or even the entire device moving intentionally or unintentionally in any direction (up/down, in/out, diagonally or rotating) that could grab, pinch, hit or trap an individual.
Noise Sound measuring over 85 decibels.
Oxidizer A substance that during a reaction (decomposition, mixing, etc.) releases oxygen to increase the flammability of both it and another nearby substance.
Particulate Material The accumulation of 40 µg/m3 or greater of airborne materials (dust, fumes or mists) less than 2.5 microns in diameter.
People’s Positions An individual’s stance that may create temporary or permanent injury (wound, fracture or strain).
Poisons/Toxins Materials that interfere with the body’s natural functioning causing illness or death.
Pressure Directed force either above 15 psig or above 15 mm of vacuum.
Reactive Material Materials when mixed with other substances generate large quantities of heat or pressure
Sensitizers Chemical or biological agents that cause a surface irritation when it comes into contact with human tissue (respiratory tract, skin, etc.).
Sharps Edges that are sharp, pointed, grounded, angled or otherwise designed and will cause damage (e.g. friction, punctures, lacerations, etc.) when an item contacts it.
State of Mind The unanticipated thinking or reaction of an individual(s) to or during an event that causes unintended consequences.
Structural Failure When an item fails because of the application of either short term or long term stresses.
Synergy The combination of a number of hazards to produce a hazard greater than the mathematic sum (e.g. 1+1=3)
Temperature Extremes When the temperature of a space is below 150 C above 370 C.
Vehicle Traffic Machines that move in a primarily horizontal direction and have operator direction.


I would suggest that spending time developing the list of hazards that you look for is far more valuable than defining the confined space itself.

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