The Problem
An upper-tier COMAH site had previously submitted a COMAH Safety Report, which was
reviewed by HSE technical specialists. One strategic topic under COMAH is functional
safety, specifically the Safety Integrity Level (SIL) requirements for safety instrumented
systems.
Earlier studies conducted by third-party consultants had resulted in unusually high SIL
targets. The site was unable to demonstrate that its existing equipment met these
targets, and achieving compliance would have required significant capital investment in
system upgrades. This created a major barrier to regulatory alignment and operational
continuity.
We were chosen for our practical approach to risk assessment and functional safety,
along with our certified competence as functional safety engineers. Our ability to
challenge overly conservative assumptions and deliver realistic, regulator-accepted
solutions was key to resolving the issue.
My Approach
We took the issue back to first principles, re-evaluating the original risk assessments which had been overly conservative. Our methodology included:
- Reviewing the original SIL determinations and identifying assumptions that inflated risk levels.
- Applying alternative risk assessment techniques aligned with UK regulatory expectations.
- Incorporating industry-wide incident data, client-specific historical data, and a review of typical practice across similar sectors to establish whether the SIL targets were consistent with what is commonly expected.
- Demonstrating that while SIL requirements still existed, they were marginal and could be addressed through ALARP arguments and cost-benefit analysis.
Our outputs were delivered in a structured report format, and we held technical meetings with the client and HSE and Environment Agency specialists to present our findings and rationale.
The Result
The project delivered:
- A reduction in SIL targets from previously unattainable levels to realistic, achievable requirements which were then eliminated through well-supported ALARP arguments and cost-benefit analysis.
- Significant cost avoidance, by preventing unnecessary upgrades and over- specification of safety systems.
- Regulatory acceptance of our revised assessment following direct engagement with HSE and Environment Agency technical specialists enabling the site to move forward with a more proportionate and achievable compliance strategy.
- A clear and defensible methodology that can be applied across other systems and sites, improving consistency and confidence in functional safety compliance.
Need Support with Functional Safety or COMAH Compliance?
If you’re facing challenges with SIL justification, functional safety assessments, or regulatory engagement under COMAH — I can help. Book your free 30-minute consultation to explore how my practical, regulator-accepted approach can reduce compliance burdens and unlock cost-effective solutions.
