Does Your HAZOP Need a Review?

As part of managing risks for any type of process, having up to date risk assessments and an understanding of the current state of operations is critical.

We've recently been engaged by clients to carry out different levels of HAZOP review, based on 5 yearly (or even longer) review cycles. Some of the key things to consider when deciding whether a review is necessary include:

• When was the HAZOP last reviewed, or when was the original carried out? If it's more than 5 years you should definitely consider a review.
• What level of change has there been since the last HAZOP? What is the state of the management of change documentation? Hopefully you have a good handle on what has changed, and changes have been risk assessed along the way, but often that isn't the case.
• Have their been any accidents or near misses, and are these well documented? These are always useful to see what has made it through all those safety barriers we take credit for in HAZOP.
• Have there been any major projects which have been assessed alongside the existing process, and has that integration been assessed? Often a project will just keep the boundaries of scope tight and not worry about the connected systems, this can be a major flaw to address at review stage.
• What is the standard of the original assessment documentation, does it stand up to scrutiny and is it comprehensive? If the HAZOP is really old, or done to a poor standard, there is a good chance it won't be fit for purpose and need re-documenting.
• Is the knowledge from the previous assessment still retained within the organisation, or have personnel changes meant comprehensive knowledge may have been lost?

There are different ways to carry out HAZOP review, varying in complexity, which depends on the starting point the quality of previous documentation:

1. Lowest time and cost effort:

Summary review. Assessing changes since HAZOP (management of change documentation) and any significant incidents or near misses. Ensuring the record of the HAZOP is accurate and documenting this review with the original documentation.

2. Medium level of time and cost effort.

In depth review of high hazard events from previous assessment (along with review of incidents and changes since last HAZOP). If there is a bit of doubt over the quality of previous studies or for example there was no risk ranking, then a detailed review of high hazard events would be merited to test how well the previous assessment was done.

3. Highest time and cost effort:

Full Re-HAZOP. In depth review of the full study - we would call this re-HAZOP. In this case it may be so long since the previous assessment or the documentation may be of a poor standard/ not comprehensive that it is felt a full re-HAZOP is required. It may be possible to pull in previous scenarios to a more comprehensive assessment, or just start from scratch.

Need help working out what you need? We can review your previous assessments, along with other documentation on your process and advise what level of re assessment might be required to give you that all important "suitable and sufficient" level of assessment needed.

Owen Llanwarne is MD of OTECSA Consulting Ltd, a process safety consultancy based in Scotland with offices in Glasgow and Cornwall. OTECSA provide expertise specialising in HAZOP, HAZID, LOPA, DSEAR and Hazardous Area Classification. This includes industries such as chemicals, pharmaceuticals, distilled spirits, petrochemicals, energy from waste, waste management and manufacturing.

https://www.otecsaconsulting.com/