Confined Space

What is a confined space? To be considered a confined space, the four criteria below need to be present:

1. Enclosed or partially enclosed space.
2. Not designed or intended for continuous human occupancy.
3. Restricted access or egress.
4. A space that is or may become hazardous to a person entering it because of its design, construction, location, atmosphere or the materials or substances in it or other conditions.

Although it is not possible to provide a comprehensive list, examples of confined spaces include: tanks, storage bins, boilers, double hulls, vats, pumping stations, kilns, pits, sumps, vaults, vessels, silos, manholes, pipelines, water reservoirs, wells, sewers, and manure pits.

The four main dangers in confined spaces are: oxygen deficiency or enrichment, fire or explosion, toxicity, and drowning in liquids or free-flowing solids. The following key actions are necessary before entering a confined space:

1. Pre-entry testing - a competent person must test the atmosphere in a confined space for oxygen level, explosive conditions, and flammable and toxic contaminants. The competent person also verifies, by tests, that all electrical equipment and machinery are locked out and in a zero-energy state.
2. Purging and ventilating - If the test results show the atmosphere may be harmful or flammable, purging and ventilating needs to be conducted. Remove air contaminants, and adjust oxygen levels by mechanical ventilation.
3. At least three people are required at a site - The entrant, a person standing at the entrance, and a back-up employee within sight and shouting distance with no obstructions or barriers to overcome to reach the space (for example, not in another room or a parking lot). Each has to be properly trained to carry out their responsibilities.
4. Personal protective equipment and lifeline - A competent person appointed by the employer must identify all required PPE and inspect it for any defects. When identified in the written report by the competent person, each entrant must wear a Class E full-body harness attached to a lifeline that is tied to a secured anchor point outside the confined space.
5. Continuous monitoring and communication - Special equipment and techniques (such as radio, microphones, hand signals and flags) must be in place to allow communication among all personnel involved with the work. In addition, where it cannot be confirmed that the concentration of toxic substances or safe levels of oxygen is able to be maintained or where there is a possibility that other hazards may occur while an employee is in the confined space, the competent person must ensure that the confined space is continuously monitored for the hazard while the employee is in the confined space.

As an employer, you must:

• Appoint a competent person to verify by tests that the
  • environment inside the confined space is not hazardous
  • oxygen level is between 19.5%  and 23% in volume
  • safe levels for the work environment can be maintained during the work inside the space
  • any substance that has the potential of engulfment and entrapment has been removed and the entry of any liquid, free flowing solids has been isolated by secure means
  • all electrical equipment and machines have been locked out, with the machines being put in a zero energy state.
  • the opening for entry and exit from the confined space will allow an employee using protective or emergency equipment to have safe passage
• Ensure that the competent person uses the appropriate and properly calibrated instruments to perform the tests inside the space.
• Ensure that the competent person provides, in a written report, the test results and an evaluation of the hazards of the space, as well as the procedures to be followed, including emergency procedures.
• Provide each employee entering the space or performing rescue operations the protective and emergency equipment identified and inspected by the competent person.
• Explain, instruct and train all employees entering the space about the procedures and the use of protective and emergency equipment
• Where the concentrations and percentage of oxygen noted above cannot be complied with, purge the confined space and have the competent person re-conduct the required tests.
• Ensure continuously monitoring for the hazards when unable to ascertain a safe environment.
• Ensure a competent person trained in the procedures is at the entrance outside the confined space, in constant communication with the employee inside and provided with a suitable alarm.
• Ensure that a competent person has a valid standard-level first aid certificate and training in CPR.
• Ensure an employee trained in the emergency procedures and hazards is in the immediate vicinity of the space.
• Permit employee to enter or remain inside a space only where the airborne dust or concentration of airborne or mixture of chemical agents does not exceed 50% of the lower explosive limit.
• Allow employees only do the cleaning or inspecting the space, and use explosion proof lighting, where the concentration of the environment does not exceed 50% of its lower explosive limit.
• Allow employees only do the cold work using non-sparking equipment and use explosion proof lighting where the concentration of the environment does not exceed 10% of its lower explosive limit.
• Ensure that when the environment inside the space is hazardous the employee uses the appropriate respiratory protective equipment (SCBA capable of providing at least five minutes reserve of air).
• Ensure that the confined space does not contain flammable or combustible substances or reactive material if the oxygen level is higher than 23%.
• Ensure that electrical equipment taken into a wet or solidly grounded space is battery operated, double insulated or bonded to ground and equipped with a tested GFCI.
• Ensure that written reports are kept at the place of employment near the confined space for a period of two years and written report to be available to an officer upon request.
• Install adequate warning signs and barricades to protect an employee in a space when a hazard from traffic exists.

While the employer is ultimately responsible for all the provisions mentioned above, the supervisor has a vital role to play in the safety of their teams. As a supervisor, you must:

• Acquaint your employees with the hazards and control measures associated with their work
• Provide the information and instruction necessary to ensure their health and safety
• Enforce company safety rules, programs, codes of practice and procedures, including ensuring employees comply with the requirements below.

As an employee, you must:

• Enter or work inside a confined space only after someone competent verifies the environment is not hazardous and the appropriate controls are taken.
• Read and understand the procedures set out in the report, be aware of hazards and acknowledge by signing a dated copy of the report.
• When entering, exiting or when occupying the confined space, follow the procedures set out in the report and use the protective and emergency equipment as required.
• Where required, wear a Class E CSA certified full body harness attached to a life line that is tied to a secure anchor outside the space as required in CAN/CSA Z259.10-M90, Full Body Harness.

General Regulation - Occupational Health and Safety Act
N.B. Reg. 91-191

Part XVII CONFINED SPACE

Section 262 Definition of "confined space"

262. In this Part, "confined space" means an enclosed or partially enclosed space not designed or intended for continuous human occupancy with restricted access or egress and which is or may become hazardous to a person entering it because of its design, construction, location, atmosphere or the materials or substances in it or other conditions, but does not include a development heading in an underground mine.

[N.B. Reg. 2022-27, s. 38]

Section 263

263. (1) Where an employee is about to enter into a confined space, an employer shall appoint a competent person to verify by tests that

(a) the concentration of airborne chemical agents or airborne dust in the confined space is not hazardous to the health or safety of the employee,

(b) the concentration of an airborne chemical agent or mixture of chemical agents or airborne dust in the confined space does not exceed 50% of its lower explosive limit,

(c) the level of physical agents in the confined space is not hazardous to the health or safety of the employee,

(d) the percentage of oxygen in the atmosphere in the confined space is not less than 19.5% by volume and not more than 23% by volume,

(e) the concentration, level or percentage referred to in paragraphs (a) to (d) is able to be maintained during the period of proposed occupancy of the confined space by the employee,

(f) any liquid in which the employee may drown or any free flowing solid in which the employee may become entrapped has been removed from the confined space,

(g) the entry of any liquid, free flowing solid or any hazardous substance into the confined space in a quantity that could endanger the health or safety of the employee has been prevented by a secure means of disconnection or the fitting of blank flanges,

(h) all electrical equipment and machines that present a hazard to an employee entering into, exiting from or occupying the confined space have been locked out, with the machines being put in a zero energy state and locked out in accordance with sections 239 and 240, and

(i) the opening for entry into and exit from the confined space is sufficient to allow safe passage of an employee who is using protective equipment or emergency equipment.

(2) The competent person referred to in subsection (1) shall, when performing the tests required under paragraphs (1)(a) to (d), use appropriate and properly calibrated instruments that have been functionally tested.

(3) The competent person referred to in subsection (1) shall in a written report

(a) set out

(i) the results of the tests made under subsection (1), and

(ii) an evaluation of the hazards of the confined space,

(b) set out the procedures to be followed by an employee entering into, exiting from or occupying the confined space,

(c) identify the protective equipment that is to be used by every employee entering the confined space,

(d) set out the emergency procedures to be followed in the event of an accident or other emergency in or near the confined space, including immediate evacuation of the confined space when an alarm is activated or there is any significant change in the concentration, level or percentage referred to in subsection (1), and

(e) identify the protective equipment and emergency equipment to be used by an employee who undertakes rescue operations in the event of an accident or other emergency.

(4) An employer shall provide to each employee entering the confined space the protective equipment referred to in paragraph (3)(c) and to each employee who may undertake rescue operations the protective equipment and emergency equipment referred to in paragraph (3)(e).

(5) An employer shall ensure that the written report referred to in subsection (3) and any procedures set out in the report are explained to an employee who is about to enter into the confined space or who may undertake a rescue operation in the confined space and the employee shall read the report and acknowledge that the report and the procedures were explained to the employee by signing a dated copy of the report.

(6) An employer shall ensure that an employee who is about to enter into the confined space is instructed and trained in the procedures referred to in subsection (3) and in the use of the protective equipment referred to in paragraph (3)(c) and that an employee who may undertake rescue operations is instructed and trained in the procedures referred to in subsection (3) and in the use of the protective equipment and emergency equipment referred to in paragraph (3)(e).

(7) Every employee who enters into, exits from or occupies the confined space shall follow the procedures referred to in subsection (3) and use the protective equipment and emergency equipment referred to in subsection (3) as required.

Section 264

264. (1) Where the tests referred to in subsection 263(1) indicate that paragraphs 263(1)(a) to (d) cannot be complied with, an employer shall, where practicable, purge the confined space to eliminate the hazards referred to in paragraphs 263(1)(a) to (d) and have the competent person re-conduct the tests required under subsection 263(1).

(2) An employer is not required to purge a confined space more than once.

Section 265

265. Where the competent person referred to in subsection 263(1) is unable to ensure that the concentration, level or percentage referred to in paragraphs 263(1)(a) to (d) is able to be maintained or where there is a possibility that a hazard referred to in paragraphs 263(1)(a) to (d) may occur while an employee is in the confined space, the competent person shall ensure that the confined space is continuously monitored for the hazard while the employee is in the confined space.

Section 266

266. (1) An employer shall ensure that

(a) all protective equipment and emergency equipment identified under subsection 263(3)

(i) have been inspected by a competent person,

(ii) are in good working order, and

(iii) are at the entrance to the confined space before an employee enters the confined space;

(b) a competent employee trained in the procedures referred to in subsection 263(3) is

(i) in attendance outside the confined space,

(ii) in constant communication with the employee inside the confined space, and

(iii) provided with a suitable alarm for summoning assistance;

(c) the competent employee referred to in paragraph (b)

(i) holds a valid standard-level first aid certificate issued by the Canadian Red Cross Society or St. John Ambulance, and

(ii) is trained in artificial respiration and cardiopulmonary resuscitation;

(d) where required under subsection 263(3), every employee entering into, exiting from and occupying the confined space wears a full body harness attached to a life line that is attached to a secure anchor outside the confined space and is controlled by the competent employee referred to in paragraph (b);

(e) where there is more than one employee in the confined space, steps are taken to ensure that any life lines attached to body harnesses worn by the employees do not become entangled; and

(f) an employee who is trained in the emergency procedures referred to in subsection 263(3) and who is fully informed of the hazards in the confined space is in the immediate vicinity of the confined space to assist in the event of an accident or other emergency.

(2) An employer shall ensure that the full body harness referred to in paragraph (1)(d) meets the requirements for Group E harnesses in CSA standard CAN/CSA-Z259.10-M90 , "Full Body Harness".

[N.B. Reg. 2001-33, s. 90]

Section 267

267. (1) An employer shall not permit an employee to enter or remain in a confined space where the concentration of an airborne chemical agent or mixture of chemical agents or airborne dust in the confined space exceeds 50% of the lower explosive limit of the chemical agent or mixture of chemical agents or dust.

(2) Where the concentration of an airborne chemical agent or mixture of chemical agents or airborne dust in a confined space does not exceed 50% of its lower explosive limit, an employer shall ensure that

(a) explosion proof lighting is used, and

(b) the only work performed by the employee in the confined space is that of cleaning or inspecting and is of such a nature that it does not create any source of ignition.

(3) Where the concentration of an airborne chemical agent or mixture of chemical agents or airborne dust in a confined space does not exceed 10% of its lower explosive limit, an employer shall ensure that

(a) explosion proof lighting is used, and

(b) the only work performed in the confined space is cold work using non-sparking equipment.

Section 268

268. Where the concentration of airborne chemical agents or mixture of chemical agents or airborne dust in a confined space is hazardous to the health or safety of an employee or where the percentage of oxygen in the confined space is less than 19.5% by volume, an employer shall ensure that an employee who enters the confined space uses appropriate respiratory protective equipment capable of providing at least five minutes reserve of unaided life support beyond the time the employee is expected to be in the confined space.

Section 270

270. An employer shall ensure that electrical equipment taken into a wet or solidly grounded confined space is

(a) battery operated,

(b) double insulated,

(c) bonded to ground, extra low voltage and not exceeding 30 volts and 100 volt-amps, or

(d) bonded to ground and equipped with a ground fault circuit interrupter of the Class A type, which is tested before each use.

Section 271

271. (1) An employer shall ensure that the written report of a competent person required under subsection 263(3) is kept at the place of business of the employer nearest to the place of employment at which the confined space is located for a period of two years from the date on which the competent employee signed the report.

(2) An employer shall make the written report referred to in subsection (1) available to an officer on request.

Section 272

272. An employer shall ensure that adequate warning signs and barricades are installed to protect an employee in a confined space if a hazard from any form of traffic exists.