Revalidate or Redo Your PHA?

You have a process hazards analysis (PHA) due this year. You started with a baseline five years ago. What are the determining factors defining if you should revalidate or redo your PHA from scratch? Complexity, recent changes, budget are essential. Let’s look at a few questions you can reflect on to decide if a revalidation or redo is right for you.

How complex is my process?

If we are talking about a system with limited threshold quantities or one hazardous chemical, a revalidation may suffice. If your process is exceptionally complicated interactively using numerous chemicals, you may want to consider a redo. It would help if you quantitatively determined how much risk is involved. In a complex system, many variables affect the hazards. Taking a fresh look at the whole system every 5 or 10 years will ensure the system does not fall victim to recurring unrecognized risks.

Have you made recent changes?

There is a tipping point when the number of changes to a process or magnitude of changes makes it easier to redo a hazards analysis instead of trying to revalidate the previous one. If your changes are minimal, revalidation is easier. If your management of change (MOC) process is robust in identifying hazards and conducting project PHAs, revalidation may be appropriate. The revalidation confirms that the MOC process covered the hazards sufficiently and validates that causes and consequences upstream and downstream are thoroughly reviewed.

Have there been any incidents in the past five years?

If there was a significant incident at your facility, it might warrant a redo to ensure that the incident is not repeated. Suppose the incident was at a similar facility within the company or in the industry recently. In that case, revalidation may be acceptable if time is spent reviewing the safeguards in place to prevent a similar incident.

Has the process run consistently with similar staff?

Staff turnover could result in new hazards. Suppose turnover time was insufficient to cover the site-specific process hazards. In that case, a redo PHA might be appropriate to ensure a complete understanding of the safe operation, design basis, and hazards present. Hazards analyses are great learning experiences, no matter your experience level but especially helpful for green operators or engineers. PHAs bring different perspectives of the process to each role involved. The team will benefit from a fresh set of eyes, whether they be innocent and inquisitive or experienced and insightful.

Is there new technology or regulation since the previous PHA?

External factors may force a redo instead of a revalidation. Typically, RAGAGEP does change often or significantly. But technological advances could have a more significant impact on process design in industries at the forefront of innovation. Regulation changes also significantly affect hazard recognition and control. The EPA and OSHA are keen on reviewing safety statistics that identify where regulation is lacking. Often regulation, after engineering advancement, governs process and process safety updates.

What is the directive from the corporate office?

Adley has worked with clients that only do redo analyses. We have worked with clients that only revalidate and other clients that prioritize revalidations based on what was done previously, i.e., not more than one or two revalidations before a redo must be conducted.

What is my PHA budget?

All else being equal, revalidations are less expensive than redo analyses. For companies with multiple PHAs due in the same year, there are a few ways to tackle the budget concerns. Revalidations could be conducted this year; then, you can begin to alternate the schedule (i.e., conduct a redo starting with one facility each year to spread the hazards analysis budget over multiple years). Another option is to prioritize the facilities requiring a redo and only conduct a few each rotation.

Complimentary Consultation

If you are still unsure if you should conduct a redo or revalidation PHA, please contact Adley Services for a complimentary consultation. Adley is a full-service engineering firm whose engineers also facilitate hazard analyses for various applications. We can help determine the best methodology and approach to your PHA, and we can assist with facilitation.

Cited sources:
Steps for updating and revalidating a Process Hazard Analysis (PHA)

CHECKLIST FOR SIMPLE REVALIDATION