What are Confined Spaces? Based on CSA Z1006-16, Management of work in confined spaces, a confined space, is defined as a workspace that: is fully or partially enclosed; is not […]
What are Confined Spaces?
Based on CSA Z1006-16, Management of work in confined spaces, a confined space, is defined as a workspace that:
- is fully or partially enclosed;
- is not designed or intended for continuous human occupancy;
- has limited or restricted access or egress, or an internal configuration that can complicate first aid, evacuation, rescue, or other emergency response services.
In other words, a confined space is a restricted space which “may become hazardous to a worker entering it”. “Thus, confined spaces are a specific type of restricted space, one in which the potential hazards within the space pose dangers above and beyond the mere difficulty of entering or leaving the space”. These hazards can emerge from the atmosphere, circumstance or activity. Atmospheric hazards can be due to an absence or overabundance of oxygen, flammable or explosive gas or particles or toxic substances in the atmosphere.
To determine whether a “space” meets the definition of a confined space consider the following 3 questions:
- Is the space fully or partially enclosed?
- Is the space not both designed and constructed for continuous human occupancy?
- Might an atmospheric hazard occur?
The word “confined” may seem to imply only a small, tight, fully enclosed space. This does NOT apply to all confined spaces in the workplace. They can be large or small, and may not be enclosed on all sides. Even if workers can move freely inside the space and the space is only partially enclosed, it may still fit this definition.
To determine if a space is designed and constructed for human occupancy, one must look at the intent and construction of the space – what is the purpose of the space, or in other words, what was it intended for, and to what standards has it been designed and constructed to allow people to occupy it? Workspaces such as offices, arenas, maintenance rooms, control rooms, etc., are obvious places that are designed for humans to occupy for long periods of time (continuously). These spaces are not considered a confined space, regardless of the atmospheric hazards that may occur in them. However, occupational health and safety legislation and regulations apply and must be complied with to protect workers.
Examples of confined spaces include silos, vats, hoppers, utility vaults, tanks, water supply towers, sewers, pipes, access shafts, truck or rail tank cars, aircraft wings, boilers, manholes, pump stations, digesters, manure pits, and storage bins. Ditches and trenches may also be a confined space when access or egress is limited. Barges, shipping containers, and fish holds are also considered as possible confined spaces.
What are the hazards related to confined spaces?
Identifying hazards in the workplace involves finding things and situations that could potentially cause harm to people. Hazards generally arise from the following aspects of work and their interaction:
- physical work environment
- equipment, materials and substances used
- work tasks and how they are performed
- work design and management
- Oxygen deficiency/oxygen enrichment
Many deaths in confined spaces are caused by a lack of oxygen. The only way to be sure there is enough oxygen is to carefully test with an oxygen monitor before you go in and if the hazard assessment states that it is necessary, while you are working in the space.
An oxygen-enriched atmosphere contains more than 23 percent oxygen by volume. This will cause flammable materials, such as clothing and hair, to burn violently when ignited. Never use pure oxygen to ventilate a confined space, since an oxygen-enriched atmosphere is a fire and explosion hazard.
Be sure the confined space has been tested fully before you enter. Continue to test, if necessary, while you are working there. If the required air quality cannot be maintained, wear the prescribed breathing apparatus. We will cover this topic in the following module.
- Flammable, combustible or explosive agents
Fires and explosions in confined spaces are often caused by gases or vapours igniting. Coal dust and grain dust may explode when a certain level of dust in the air is reached. Some other common substances that can cause explosions or fires in confined spaces are: Acetylene gas from leaking welding equipment, Methane gas and hydrogen sulphide gas produced by rotting organic wastes in sewers or tanks, Hydrogen gas produced by contact between aluminum or galvanized metals and corrosive liquids and Grain and coal dust.
- Toxic air contaminants, smoke, fumes, and dusts
- Residual chemicals/materials
- Ignition hazards, including hot work, tools and other potential sources of ignition
“Hot work” means any work where the flame is used or a source of ignition may be produced. Unless a qualified person has determined that the work can be performed safely, hot work shall not be performed where there are concentrations of explosive or flammable hazardous substances that do not meet the prescribed standards.
- Chemical contact hazards, including acids, alkalis
- Physical hazards, including mechanical hazards, thermal stress, humidity radiation, noise and vibration, working/walking surfaces, engulfing materials, physical obstacles, poor visibility.
Poor visibility increases the risk of accidents and makes it harder for a standby person to see a worker who may be in distress. If poor visibility results from inadequate lighting, the light levels should be increased (although area lighting is not always required). If activities such as sandblasting or welding result in poor visibility, appropriate ventilation may be needed to reduce harmful substances in the air. If portable lighting is used where there may be an explosive atmosphere, the lighting must be “explosion-proof.” (The Canadian Electrical Code has a description of lighting that is approved for use in explosive atmospheres.)
Whenever unstable solids made of small particles like sand or grain are stored in enclosures, there is a danger of the materials flowing onto workers and trapping or burying them. Examples of these confined spaces are sand bins, wood chip or sawdust bins, storage or grain silos, and potash feed systems.
The space you are about to enter may have a hatchway that is difficult to squeeze through, and ladders for ascending or descending. You are therefore at risk of falling while getting into the space as well as while you are inside. In addition, the flooring of tanks or other wet environments or the rungs of a ladder may be very slippery. If the hazard cannot be eliminated and there is a danger of falling from a height, a fall protection system (such as guardrails or a harness and lifeline) may be needed.
In a confined space there may be the danger of being struck by falling objects such as tools or equipment, particularly if access ports or workstations are located above workers. If workers might be exposed to the hazard of falling objects, safe work procedures must be put in place to prevent this. For example, schedule work activity so that no worker is working above another, and lower equipment and tools into the space before workers enter and remove them after workers leave the space.
- Electrical hazards, including lines and cables, exposed terminals.
- Traffic hazards, including pedestrian, mobile equipment.
- Biological hazards, including animals and biological agents.
- Other hazards related to the confined space, including piping/distribution systems, pressurizing fluids, any type of uncontrolled energy (water, liquid, vapour, electric, magnetic, gaseous, etc.), limited access and egress.
The traditional hazard control methods found in regular worksites can be effective in a confined space. These include elimination, engineering controls, administrative controls and personal protective equipment. Engineering controls are designed to remove the hazard while administrative controls and personal protective equipment try to minimize the contact with the hazard.
All employees must wear the appropriate PPE when working in or around a confined space. It is the responsibility of the employer to ensure the correct PPE is provided to the worker. The supervisor is responsible to enforce that all PPE is being worn correctly. In some cases, the employer will tell workers to provide their own PPE such as their own eyewear, hard hats and safety footwear. Please note that all PPE has to be CSA approved.
Who needs confined space training?
Confined Space training is required by all jobs where employees might work in or around confined spaces, even if this only happens for less than a full day per year. The course is geared towards existing employees, as well as businesses looking for an affordable solution to comply with the latest safety regulations.
Many industries require their employees to work in confined spaces. The most common are:
- Oil & Gast.
- Energy & Electricity.
- Waste Management.
Newfoundland and Labrador employees must undergo a WorkplaceNL-approved “hands-on” training course.
Are there different levels of confined space training?
Our Confined Space course teaches employees the hazards of confined spaces and basic information on working safely with and around confined spaces. Most employees will require additional training and hands-on practice that teaches them more about their specific role in the confined space.
Confined space entrants, attendants and supervisors require an additional type of workplace-specific training. This type of training should include information on how to use the equipment and how to review the required personal protective equipment such as Self-Contained Breathing Apparatus (SCBA), Supplied Air Respirators (SAR) and Cartridge Respirators. Employees should also learn methods to rig overhead anchors, using tripods and safety lines, retractable lifelines and winch systems, operating rope-based mechanical hauling systems and using remote casualty connection techniques. Rescuers also require additional training which can be very extensive, depending on the type of rescue that a worker may encounter.
Where to get Confined Space Training and can you do confined space training online?
eSafetyFirst Confined Space Training program has been developed in accordance with provincial legislation as safety training for workplaces across Canada. This course consists of 4 modules and tests. Once you pass all the tests, you may print your certificate of completion (wallet & wall-sized). Training may be paused or resumed at any time, is fully narrated, and includes interactive exercises to ensure understanding of course content.
If you have a confined space on-site, all workers should be trained in the hazards of confined spaces. General training (such as this course) will cover the legislation, recognizing a confined space, recognizing the hazards and how they are assessed and the contents of an Entry Plan.
Additionally, all confined space training should include some hands-on training with the safety equipment including the personal protective equipment and safety harnesses.
Workers with emergency rescue responsibilities will need training related to the rescue.
Regardless of the source of training or how it is provided to workers, the employer has the duty to ensure it is adequate to protect the health and safety of the workers who work in or around the confined space.