Reference Guide

Ontario Regulation 632/05 Explained: A Plain-Language Guide to Ontario's Confined Space Regulation

Section-by-section plain-language guide to Ontario's confined space regulation: scope, definitions, the written program, hazard assessment, the entry permit system, atmospheric testing, rescue, and penalties.

What O. Reg. 632/05 Applies To

Section 2 of the regulation states it applies to all workplaces to which the Occupational Health and Safety Act applies, with specific exclusions in Section 3. The regulation does not apply to:

Diving operations as defined in O. Reg. 629/94
Emergency work performed by firefighters in certain circumstances
Work covered by sector-specific regulations: Construction Projects (O. Reg. 213/91), Mines and Mining Plants (Reg. 854), Health Care and Residential Facilities (O. Reg. 67/93), and Industrial Establishments (Reg. 851), though confined space requirements within Reg. 851 still apply where relevant

For the vast majority of Ontario workplaces, including manufacturing, food and beverage processing, agriculture, municipal infrastructure, utilities, and most industrial settings, O. Reg. 632/05 is the governing regulation for confined space work.

How a Confined Space Is Defined

Under Section 1 of O. Reg. 632/05, a confined space is defined as a fully or partially enclosed space:

That is not both designed and constructed for continuous human occupancy
In which atmospheric hazards may occur because of its construction, location, or contents, or because of work that is done in it

Both criteria must apply for the regulation to engage. A space that is enclosed but designed for occupancy (an office, warehouse) is not a confined space. A space that could become hazardous but is designed for occupancy is also not a confined space.

Common examples in Ontario industrial and agricultural workplaces include:

Grain bins and silos
Feed mixers and feed pelleting equipment
Manure pits and lagoons
Storage tanks (chemical, fuel, water)
Process tanks at food and beverage processing facilities
Vaults, sumps, and underground utility chambers
Boilers and pressure vessels under maintenance
Trenches and excavations meeting the criteria
Cargo holds and rail tank cars during inspection or repair

The Written Confined Space Program (Section 5)

If a workplace includes any confined space that workers may enter, Section 5 requires the employer to develop and maintain a written program before any worker enters. The program must:

Apply to one or more confined spaces (a single program can cover multiple spaces)
Be developed in consultation with the joint health and safety committee or health and safety representative
Provide for: a method for recognizing each confined space, a method for assessing hazards, a method for developing plans, a method for general training, an entry permit system, and an emergency procedure

The program is the foundational document. Without it, an employer cannot demonstrate due diligence regardless of how thorough other documentation appears.

The Hazard Assessment (Section 6)

Section 6 requires that before any worker enters a confined space, the employer must ensure an adequate assessment of hazards has been carried out. The assessment:

Must be in writing
Must consider hazards that may exist due to the design, construction, location, use, or contents of the confined space
Must consider hazards that may develop while work is done inside
May be incorporated into an entry permit under Section 10
May cover multiple similar confined spaces in a single document if they have the same hazards
Must be reviewed as often as is necessary to ensure the relevant plan remains adequate (Section 6(9))

The phrase "as often as is necessary" is the heart of the review requirement. There is no fixed timeline. Industry practice often uses a 3-year cycle, but the regulation requires reviews whenever conditions change. For more on this specific question, see how often a confined space assessment needs to be updated.

The Written Plan (Section 7)

Section 7 requires that before any worker enters a confined space, the employer must ensure an adequate written plan is developed and implemented by a competent person. The plan must include procedures for controlling each hazard identified in the assessment, plus specific elements:

Adequate procedures for working in the presence of explosive or flammable substances (Section 19)
Ventilation and purging procedures (Section 20)
Atmospheric testing procedures
Emergency response and rescue procedures
Procedures for the use of personal protective equipment
Procedures for the duties of attendants

The plan may be incorporated into the entry permit. One plan may cover multiple confined spaces if they share the same hazards.

Training (Section 8)

Section 8 requires that workers and supervisors receive adequate training to recognize and control the hazards involved in confined space work. Training must include:

General training on the workplace's confined space program
Specific training on the hazards and procedures for each confined space the worker may enter
Training on the use of equipment, including personal protective equipment, atmospheric testing devices, and rescue equipment

The training must be provided by a person of adequate knowledge and training. Records of training are essential for demonstrating due diligence.

The Entry Permit System (Section 10)

Section 10 requires that no worker enter a confined space unless an entry permit has been issued by the employer. The permit must:

Be in writing
Be issued before each entry
Identify the confined space, the work to be done, the date and time of entry, and the workers entering
Reference the assessment and plan
Be retained as a record

The permit is the link between the foundational program and the day-of entry. It documents that all required preconditions have been verified before entry begins.

Atmospheric Testing

Sections 11 through 15 cover atmospheric testing requirements. Before entry and during occupancy, atmospheric tests must verify:

Oxygen content between 19.5 and 23 per cent by volume
Concentrations of explosive or flammable substances below the lower explosive limit
Contaminant levels within applicable exposure limits

Testing must be performed using calibrated equipment and by persons trained in its use.

Rescue Procedures and Equipment

Sections 16 through 18 require that the employer establish rescue procedures and ensure rescue equipment is available before any worker enters a confined space. Rescue planning must consider:

The hazards of the confined space
The expected duration of work
The skills and equipment required for rescue
Communication systems for the entrant, attendant, and rescue personnel

A rescue procedure that depends on emergency services arriving in time is generally not adequate. Most Ontario confined spaces require self-rescue, non-entry rescue, or trained on-site entry rescue capability.

Penalties Under O. Reg. 632/05

Contravention of any requirement of the OHSA and its regulations is an offence. Maximum penalties are:

Up to $25,000 or imprisonment for up to 12 months, or both, for an individual
Up to $500,000 per corporation per offence

Penalties have been pursued in cases where employers failed to develop programs, conduct assessments, or maintain rescue capabilities. The financial penalties are not the most serious consequence: incidents resulting in worker injury or fatality often lead to additional charges under the OHSA general duty clause. For more on the general duty clause, see OHSA Section 25(2)(h) and Due Diligence Explained.

Common Mistakes Ontario Employers Make

In CCL's practice, the most common O. Reg. 632/05 compliance gaps include:

No written program at all (most common at small employers)
Programs that exist on paper but are not communicated to workers
Hazard assessments performed once and never reviewed
Entry permits that are filled out but not actually verified before entry
Training records that are not kept up to date as workers change roles
Rescue plans that depend on emergency services rather than internal capability
Failure to identify all confined spaces (overlooking unobvious ones like vaults, sumps, or new equipment)
No coordination between multiple employers when contractors are involved (Section 4 lead employer requirements)

How CCL Health & Safety Helps

CCL Health & Safety builds confined space programs to O. Reg. 632/05. We carry out hazard assessments, develop written plans, structure entry permit systems, train workers and supervisors, and produce documentation that holds up to MLITSD inspection.

For workplaces under federal jurisdiction, the equivalent regulation is Part XI of the Canada Occupational Health and Safety Regulations. See Part XI of COHSR Explained for the federal counterpart, or Provincial vs Federal Confined Space Regulations for a side-by-side comparison. For the National Standard of Canada that complements O. Reg. 632/05, see CSA Z1006:23 Explained. For more on our program development services, see Confined Space Program Development.

Read the Source

Read the full text of Ontario Regulation 632/05 at the official Government of Ontario e-Laws site: ontario.ca/laws/regulation/050632.

Frequently asked questions

When does O. Reg. 632/05 require a written confined space program?+

Whenever a workplace contains a confined space that workers may enter. Section 5 requires the employer to develop and maintain the written program before any worker enters, in consultation with the joint health and safety committee or health and safety representative. The program covers hazard recognition, assessment methodology, plan development, training, the entry permit system, and emergency procedures.

Who is a competent person under O. Reg. 632/05?+

A competent person is defined under the OHSA as someone qualified by knowledge, training, and experience to perform the work, who is familiar with the OHSA and applicable regulations, and who has knowledge of the potential hazards. For confined space work, this typically means a CRSP-credentialed practitioner or equivalent with confined space experience. The competent person develops and implements the written plan under Section 7.

How often does the hazard assessment need to be reviewed?+

Under Section 6(9), as often as is necessary to ensure the relevant plan remains adequate. There is no fixed timeline in the regulation. Industry practice often uses a 3-year cycle as conservative due diligence, and reviews must also be triggered whenever physical, operational, or material conditions change.

What are the penalties for non-compliance with O. Reg. 632/05?+

Under the OHSA, individuals can face fines of up to $25,000 or 12 months imprisonment per offence. Corporations can face fines of up to $500,000 per offence. Incidents resulting in injury or death often lead to additional charges under the OHSA general duty clause at Section 25(2)(h).

Does O. Reg. 632/05 apply to farms?+

O. Reg. 632/05 applies to most Ontario workplaces under the Occupational Health and Safety Act, including most provincial farm operations. Federally regulated agricultural workplaces such as licensed grain elevators or feed mills connected to inter-provincial trade fall instead under Part XI of the Canada Occupational Health and Safety Regulations. The jurisdictional question must be answered first.

Next Steps

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More resources

Provincial vs Federal Confined Space Regulations in Canada: A Complete Guide
How to tell which regulatory framework applies to your workplace, the structural differences between O. Reg. 632/05 and Part XI of COHSR, and what each requires for hazard assessment, oxygen levels, training, and documentation.
How Often Does a Confined Space Assessment Need to Be Updated Under O. Reg. 632/05?
Section 6(9) is performance-based, not calendar-based. A breakdown of what it really requires, what triggers a review, where the 3-year industry practice comes from, and the documentation that proves due diligence.
Part XI of COHSR Explained: A Plain-Language Guide to Federal Confined Space Regulations
Plain-language guide to the federal confined space framework: when Part XI applies, the 2021 amendments, the new distinction between confined spaces and hazardous confined spaces, qualified person reports, and entry procedures.
CSA Z1006:23 Explained: A Plain-Language Guide to the Canadian Standard for Confined Space Management
Plain-language guide to Canada's national standard for confined space program management: the Plan-Do-Check-Act framework, what the 14-area scope covers, how it relates to provincial and federal regulations, and what changed in the 2023 edition.
OHSA Section 25(2)(h) Explained: Due Diligence and the General Duty Clause in Ontario
Plain-language guide to Ontario's general duty clause: how Section 25(2)(h) operates, the nine measures of due diligence Ontario courts apply, and how the clause interacts with O. Reg. 632/05 in confined space cases.
CSA Z460:20 Explained: A Plain-Language Guide to the Canadian Standard for Hazardous Energy Control
Plain-language guide to the National Standard of Canada for hazardous energy control: the lockout-first principle, machine-specific energy control procedures, annual audits, training requirements, and what changed in the 2020 edition.
Ontario Regulation 851 LOTO Requirements: A Plain-Language Guide to Lockout/Tagout in Ontario Industrial Workplaces
Section-by-section guide to the LOTO-relevant provisions of Ontario's Industrial Establishments regulation: Section 42 (electrical), Section 75 (motion stopped), Section 76 (locking out), Section 78 (energy release), and Section 119.13 (confined space lockout).

All Resources