When equipment or processes are introduced or modified in an Ontario factory, a Pre-Start Health and Safety Review (PHSR or PSR) is frequently required under Section 7 of Regulation 851, the Industrial Establishments Regulation.

While clients sometimes view the PHSR report as delivering "bad news" due to identified deficiencies, the goal is to eliminate or control hazards before the apparatus or process is operated or used. The review focuses heavily on functional safety and achieving measurable performance levels to protect workers.

Here is a quick overview of the sections within our typical PHSR reports and what they mean for your workplace safety.

 

The Safety Foundation, Risk Assessment and PLr

The risk assessment, the cornerstone of machinery safety, involves hazard identification, risk analysis and evaluation. We include this section because often, customers haven't performed a documented risk assessment, yet we require one to properly evaluate the machine's safety systems.

The risk assessment doesn't just list hazards; it quantifies the required integrity of the safety systems. This quantification results in the Required Performance Level PLr, which is the discrete level specifying the ability of the Safety-Related Parts if the Control Systems (SRP/CS) to perform a safety function under foreseeable conditions.

A Task-Based Approach: Our risk assessments are typically task-based, analyzing hazards associated with specific activities performed by different personnel throughout the machine's lifecycle. This includes:

  • Operators (during production).
  • Setup Technicians.
  • Maintenance/Repair Staff.
  • Passersby (affected persons).

 

The Safety Circuit Blueprint (PL and Category)

Once the required level of risk reduction, Plr is determined, we evaluate the machine's safety circuitry to ensure it meets that level of performance (PL).

Performance Level (PL): We typically include an explanation and statement confirming the achieved Performance Level (PL) of the safety circuits. The determination of the achieved PL is an estimation based on several quantifiable aspects:

  • The mean time to dangerous failure (MTTFd).
  • The Diagnostic Coverage (DC) quantifies the effectiveness of self-testing and monitoring measures.
  • Measures against Common Cause Failure (CCF).
  • The structure (or designated architecture).

However, for many systems we review, the client provides neither the PL calculation nor sufficient information to perform it. In those cases, we can still review the system to a minimum Safety Circuit Category with a stated caveat regarding the PLr.

Safety Circuit Category: The structure of the safety circuit is designated by its Category (B, 1, 2, 3, or 4). The Category specifies how a safety circuit is physically wired and how it detects and reacts to faults. To achieve a higher PLr (such as PLd, commonly required for hazards that can cause permanent injury), the safety circuit must typically meet Category 3 or Category 4 architecture. 

 

Reporting Non-Compliance (Guard Checks and E-Stops)

The PHSR report's ultimate function is to identify and document non-compliance.

Safety Circuits and Guarding: This section summarizes noncompliance issues for safety circuits and guarding. For instance, this addresses safeguarding devices that signal a stop, such as barrier guards, and interlocking electrical devices, which fall under Item 2 of the Regulation 851 Table. Furthermore, we rigorously check physical guards against reach hazards, sometimes referred to by the acronym "A.U.T.O." (around, under, through, and over).

Non-Guarding Items (Emergency Stops): Non-guarding related items, such as emergency stops, which are complementary protective measures. Their circuits must also meet a minimum performance level (PLc). 

 

Final Takeaway

The written report resulting from the PHSR must include details of the measures required to bring the apparatus into compliance with the applicable sections of Regulation 851. Remember that while our report identifies the necessary measures for compliance, the employer ultimately bears the responsibility for implementing these recommendations and complying with the law.