PSR's and H&S

Providing Reports for Pre-Start Health and Safety Reviews.

PSRs are intended to identify potential hazards to workers in a factory and recommend remedial measures to control or remove these potential hazards.

Before an apparatus, structure, protective element or process (or modification to an apparatus, structure, protective element or process) is operated or used in that factory. “Control or removal” means that measures are identified to provide that the sections referenced in Section 7 (and, where applicable, the standards or codes approved by the MOL) are met.

Professional engineers should understand that the requirements for PSRs are limited to the circumstances defined in the Table.

Provision Table (1 Table: taken from Section 7, Ontario Regulation 528/00, Occupational Health and Safety Act)


Applicable provisions of Regulation 851



Subsections 22 (1), (2) and (4)

Flammable liquids are located or dispensed in a building, room or area.


Sections 24, 25, 26, 28, 31 and 32

If any of the following are used as protective elements in connection with an apparatus:

Safeguarding devices that signal the apparatus to stop, including but not limited to safety light curtains and screens, area scanning safeguarding systems, radio frequency systems and capacitance safeguarding systems, safety mat systems, two-hand control systems, two-hand tripping systems and single or multiple beam systems.

The barrier guards use interlocking mechanical or electrical safeguarding devices.


Clause 45 (b)

Material, articles or things are placed or stored on a structure that is a rack or stacking structure.


Section 63

A process involves a risk of ignition or explosion that creates a condition of imminent hazard to a person's health or safety.


Section 65

The use of a dust collector involves a risk of ignition or explosion that creates a condition of imminent hazard to a person's health or safety.


Sections 87.3, 87.4, 87.5 and 88, subsections 90 (1), (2) and (3), and sections 91, 92, 94, 95, 96, 99, 101 and 102

A factory produces aluminum or steel or is a foundry that melts material or handles molten material.


Sections 51 and 53

The construction, addition, installation or modification that relates to a lifting device, traveling crane or automobile hoist.


Sections 127 and 128

This process uses or produces a substance that may result in the exposure of a worker in excess of any occupational exposure limits as set out in Regulation 833, 835, 836, 837, 838, 839, 840, 841, 842, 843, 844, 845 or 846 of the Revised Regulations of Ontario, 1990.

While professional engineers who undertake PSRs are responsible for identifying and addressing issues of compliance with the applicable sections of Regulation 851, professional engineers do not bear responsibility for implementing the report recommendations. The employer remains responsible for ensuring that all requirements of the Occupational Health and Safety Act and Regulations are complied with in the workplace. Even where a Pre-Start Health and Safety Review is not required or an exemption from the requirements of Section 7 applies, the employer must ensure that workers are protected before operating any apparatus, structure, protective element or process in the workplace.

Section 7 of Regulation 851 of the Occupational Health and Safety Act (OHSA) requires that in certain circumstances an owner, lessee or employer obtain a written report signed and sealed by a professional engineer containing:

  • details of the measures to be taken for compliance with the relevant provisions listed in Table 1 of Section 7 of Regulation 851 (the Table);
  • if testing is required before the apparatus or structure can be operated or used, or before the process can be used, details of measures to protect the health and safety of workers that are to be taken before the testing is carried out; and
  • if item 3 or 7 of the Table applies, details of the structural adequacy of the apparatus or structure.

This will be referred herein as the report.

The purpose of the report is to ensure that a timely professional review identifies non-compliance, including non-compliance associated with exposure to chemicals and other designated substances, in those specific circumstances identified in the Table. A PSR is required:

  • because a new apparatus, structure or protective element is to be constructed, added or installed or a new process used, as identified in the Table; or
  • because there is to be a modification to an existing apparatus, structure, protective element or process, as identified in the Table.

The report should identify the items of non-compliance and must indicate what measures are necessary to bring the apparatus, structure, protective element or reviewed process into compliance with applicable sections referenced in Section 7 of Regulation 851. Where no items of non-compliance are identified in the course of the PSR, the report should indicate that the apparatus, structure, protective element or process complies with the applicable sections referenced in Section 7 of Regulation 851.

PSRs are mandatory only in factories that are provincially regulated. A factory is broadly defined in the OHSA but does not include federally regulated workplaces or workplaces such as mines or mining plants, construction sites, logging operations, health care facilities or educational facilities. (See Section 8.1 Cautionary Advice).

To obtain more information on the OHSA and Regulation 851, contact the local district office of MOL.  The address of the local district office can be found in the blue pages of the local telephone directory. In addition, a list of local district offices is maintained on the MOL website at