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

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, agri-business such as commercial feed mills and grain handling, municipal infrastructure, utilities, and most industrial settings, O. Reg. 632/05 is the governing regulation for confined space work. It does not apply to farming operations (s. 3(1)(c)).

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 $2,000,000 per offence for a corporation
• Up to $1,500,000 per offence for a director or officer
• Up to $500,000 and up to 12 months in jail per offence for any other individual
• A mandatory 25 per cent victim fine surcharge on top of every fine

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.