Ontario industrial establishments are subject to multiple safety review requirements, but confusion often arises around the purpose of different evaluations. Many facilities assume that a single review satisfies all obligations, when in reality different safety processes serve different regulatory and engineering functions. Understanding the distinction between plant safety audits and engineering safety reviews is essential for maintaining compliance and preventing enforcement action.
Facilities that clearly separate these processes are better positioned to meet OHSA requirements and address hazards before regulators intervene.
Why Ontario Facilities Need to Know the Difference
Ontario’s safety framework emphasizes prevention through oversight, documentation, and engineered controls. While both audits and engineering reviews contribute to safer workplaces, they are not interchangeable. A health & safety audit assesses overall compliance, while engineering reviews assess whether equipment and systems are designed to be technically safe.
Failing to apply the correct review at the right time can result in hidden gaps that are not identified until a Ministry of Labour inspection.
What Is a Safety Audit?
A health & safety audit is a structured evaluation of workplace practices, documentation, and compliance with OHSA requirements. It reviews whether safety policies are in place, inspections are conducted, and corrective actions are tracked.
An industrial safety audit typically examines conditions such as:
- Guarding presence and general condition
- Electrical safety practices
- Housekeeping and access routes
- Maintenance records and inspection logs
- Incident reporting and follow-up
These audits are often repeated regularly and help organizations maintain consistency across departments. Many facilities rely on a qualified safety audit company to conduct objective reviews and identify compliance gaps before enforcement action.
What Is a PSHSR and an Engineering Safety Review?
An engineering safety review is a technical evaluation focused on equipment design, modification, or installation. In Ontario, this often takes the form of a pre-start health and safety review (PSHSR) under Ontario Regulation 851.
Unlike audits, engineering reviews assess whether hazards are adequately controlled through design. This includes evaluating guarding systems, control reliability, safe access, and exposure to mechanical or process-related risks. Engineering reviews result in formal documentation prepared by licensed professional engineers and must be completed before equipment is placed into service.
Scope: General Conditions vs. Engineering Design Hazards
The primary difference between these processes lies in scope. Plant safety audits assess general workplace conditions and management systems. They determine whether safety programs are functioning as intended and whether required procedures are being followed.
Engineering reviews focus exclusively on technical hazards. They examine whether the physical design of machinery or systems meets regulatory requirements. An audit may confirm that guarding exists, but an engineering review determines whether that guarding is sufficient, correctly positioned, and resistant to bypassing.
Both reviews are necessary, but each addresses different risk layers.
Who Conducts Each Type and Under What Regulation
A health & safety audit may be conducted internally or by an external safety audit company. Auditors assess compliance with OHSA and internal safety programs, but do not provide engineering services. Licensed professional engineers must conduct engineering safety reviews. These reviews are required under Ontario Regulation 851 when specific conditions exist. Engineers assume accountability for their findings and provide certified documentation that demonstrates compliance.
Use Cases: When to Perform an Audit vs. PSHSR
Choosing the correct review depends on the situation. Plant safety audits are appropriate for evaluating ongoing operations, aging equipment, or overall compliance readiness. They are particularly useful for identifying gaps in documentation, inspections, or maintenance practices.
Engineering safety reviews are required when new equipment is installed, machinery is modified, or layouts are changed in ways that affect worker exposure. In these cases, a PSHSR must be completed before startup to confirm compliance.
Using one process in place of the other creates compliance gaps that audits alone cannot address.
Choosing the Right Safety Review for Compliance and Prevention
Ontario facilities cannot rely on a single safety process to address all risks. Industrial safety audits provide broad oversight, while engineering safety reviews ensure that hazards are controlled at the design level.
SAFE Engineering Inc. supports compliance through detailed plant safety audits that identify engineering gaps and support corrective action planning. By applying the right review at the right time, facilities can strengthen safety performance, prevent enforcement orders, and maintain long-term regulatory confidence. Contact us today!
