Confined Spaces

Working in a confined space is a common activity observed in many industries and being familiar with the NL OHS Regulations, is a must for keeping yourself and other safe while on the job! Regulations can be found here: Part XXVI, Confined Space Entry.

A confined space is a partially or fully enclosed space that meets ALL the below listed criteria:

  1. is not designed or intended for human occupancy except for the purpose of performing work;
  2. has restricted means of access and egress; and,
  3. may become hazardous to a person entering it as a result of its design, construction, location or atmosphere, the materials or substances in it, or any other conditions relating to it.

Examples include, but are not limited to, vaults, tunnels, sewers, pipes, boilers, manholes, ductwork, etc.

Employers must complete an assessment to determine whether a work area is a confined space, and workers must assume it’s a confined space until it has been determined that it is not. If it is deemed a confined space, then additional requirements are needed in order to proceed safely with the job. When there is doubt pertaining to workers safety and or the ability to control a hazard, there is nothing wrong with deeming the space a confined space even if it does not meet all 3 criteria as listed above.

Hazards

Prior to starting any job, all hazards must be identified and controlled; generally, a hazard assessment is an easy way to assist with this process. However, when working in a confined space, the risk of a hazard resulting in an incident is high if appropriate controls are not implemented.

Some common hazards you are likely to encounter while working in a confined space are listed below:

  • Engulfment – occurs when fumes, liquid, or solid substances trap the entrant. Death can occur due to inhaling the substance or by surrounding the entrant causing strangulation, constriction or crushing (e.g., trench cave-ins).
  • Mechanical- spring-loaded equipment.
  • Hydraulic – fluid pressure.
  • Pneumatic – air pressure.
  • Traffic – vehicular and pedestrian.
  • Falling objects and suspended loads.
  • Flowing fluids and open drains.
  • Conveyors.
  • Weather phenomena.
  • Work activities

  • Bacteria – fecal matter and sludge.
  • Viruses.
  • Fungi.
  • Mould.
  • Animals – insects and rodents.
  • Sharp objects – needles and rust.

  • Electrical – lights, live wires, static, other electrical equipment, and sparking tools.
  • Noise.
  • Heat – hot surfaces and steam.
  • Cold – icy surfaces.
  • Radiation – lasers and X-rays.
  • Inadequate lighting.
  • Vibration.

  • Long traverses.
  • Low ceilings.
  • Vertical drops or rises.
  • Slippery surfaces.
  • Narrow spaces.
  • Sloped surfaces.
  • Compartments.
  • Altitude – high (e.g., towers) or low (e.g., shafts).

Oxygen Deficiency – normal atmosphere is composed of approximately 21% oxygen and 79% nitrogen. An atmosphere is considered to be oxygen deficient when the oxygen in the air is less than 20%.  Oxygen deficiency is one of the leading causes of death in confined spaces.

An atmosphere is considered oxygen-enriched when the oxygen in the air is more than 22%.  An oxygen enriched atmosphere is a fire and explosion hazard.

A flammable or explosive atmosphere is present where explosive or flammable vapours, gases or dust are in such concentrations that they are within their explosive/flammability limits and that, when exposed to an ignition source (such as a spark), will explode or catch fire.

A toxic atmosphere can be present or develop within a confined space. This might be due to what is (or was) being stored inside it or created by the work activity. Activities such as welding, painting, sanding as well as cleaning or degreasing with solvents can produce very toxic vapors. In addition, products stored inside a confined space can be absorbed into the walls and give off toxic vapors when they are removed or during cleaning operations. It is also important to note that toxic atmosphere from outside the space can also enter a confined space.

Hazard Assessment

A hazard assessment is a process used to identify hazards and eliminate or reduce the risk of injury or loss.  The steps of a hazard assessment include:

  1. Identify the Hazard – Review the workplace and/or a specific task to identify real and potential hazards.
  2. Evaluate the Risk – Estimate the potential loss to people, equipment, materials, and environment due to the hazard.
  3. Select Appropriate Controls – Controls are used to eliminate the hazard or reduce the risk of injury, illness or damage.
Confined Space Hazard Assessment

A confined space hazard assessment is similar to a regular hazard assessment, but it is an important tool to ensure hazards, specific to the work environment or confined space, have been identified and controlled.

The confined space assessment MUST be:

  • Completed by a competent person and be signed, dated, kept on location, and updated as needed.
  • Prior to starting work, it needs be reviewed with personnel and updated, where applicable, to include:
    • current scope of work, and
    • changes that can affect the confined space such as introduction of new work procedures, materials, machinery, or equipment
  • Available to applicable workers AND the OHS Committee or WHS Representative &/or Designate.

Common Controls

Controls are critical in managing hazards associated with work and tasks. Everyone has responsibilities to work safely but, considering the serious hazards and risk associated with confined space work, it is important to implement effective measures using the hierarchy of controls. The hierarchy of controls ranks controls from the most effective level of protection to the least effective level of protection. Consider the following control measures:

Confined spaces must be identified by a sign located at each external entry point and shall:

  • Identify the space as a confined space
  • Identify access restrictions
  • Indicate that a permit is required prior to entry
  • Be sufficiently durable to withstand the environment in which it will be placed

Atmospheric testing must be completed and recorded before entry into the confined space, after interruption in work procedures, and at appropriate intervals. This involves using a gas tester to determine if atmospheric levels in the space are sufficient or if further controls need to be implemented. When testing, the following should be tested (at a minimum):

  • Oxygen content – between the acceptable range of 20%-22%
  • Potential accumulation of flammable, combustible, or explosive agents
  • Accumulation of atmospheric contaminants

The confined space is to be fully isolated by locking out all sources of energy (including mechanical, electrical, hydraulic, pneumatic, thermal, steam, and gravity), protecting against moving or shifting materials, as well as contaminants that could enter the confined space through process lines, drains, or vents.

Where an atmospheric hazard exists, or is likely to exist, the space must be purged and/or ventilated to ensure acceptable atmospheric levels before any worker enters the space.

Suitable means to enter/exit the space should be provided to workers and not impede their exit.  This would take into consideration of the size of the confined space, PPE used by the workers, etc.

Ensure that entrants and attendants have sufficient communication between each other, as well as communication between the attendant and rescue personnel.  An acceptable means of communication must be identified and utilized when working in confined spaces.  This can include voice, visual, alarm activated communication, or another effective means.

The permit documents the atmospheric tests and safety precautions that have been taken to address the identified hazards.  Prior to entry, all personnel involved (entrants, attendants, supervisors, etc.) would review and sign-off on the permit.  This permit is kept near the entrance to the confined space and the attendant would record entries/exits, atmospheric levels, etc.

Depending on the space and hazards, appropriate PPE must be selected and worn by the entrants. This will vary but can include, but not limited to:

  • Steel toed footwear
  • Hard Hat
  • Safety glasses/goggles
  •  Gloves
  • Respiratory protection
  • Protective clothing
  • Fall protection equipment
  • Hearing protection

Prior to the commencement of work, an emergency response plan must be developed and communicated to all workers. This will include:

  • The various situations when each type of rescue will be used
  • Communication between entry team and other emergency response members
  • Set-up and operation of rescue equipment
  • Rescue procedures
  • Emergency medical care and materials that will be available to treat injured entrants on site.

Training Requirements

In accordance with NL OHS Regulations, personnel must not enter a confined space unless they have completed a training course approved by WorkplaceNL – 2 Day Confined Space Entry.  Additionally, personnel must be aware that entry into a confined space is defined as when the breathing zone (the area within a 10-inch radius of the worker’s nose and mouth) of the worker breaks the plan of the opening to the confined space.

Training is required for:

  • Entrants
  • Attendants
  • Supervisors
  • Emergency response team

In addition to WorkplaceNL training, which is valid for 3 years, workers must receive instruction and training on specific procedures and equipment that they may be required to use such as the air or gas monitoring equipment, rescue equipment, safety data sheets, emergency response, etc.

NLCSA Confined Space Entry Resources

TitleCategoriesFile TypeLink
Working in a Confined SpaceGeneralpdf
Download
Carbon MonoxideGeneralpdf
Download
Lock Out Tag OutLock Out Tag Outpdf
Download
Confined Space Entry Program v1.0High Risk Activity, Safe Job Proceduresdocx
Download
Attic and Crawl Space Work ProcedureSafe Job Proceduresdocx
Download
Respiratory Protection Program v1.0Personal Protective Equipment, Safe Job Proceduresdocx
Download

External Resources

NL OHS Guide – Confined Space Entry