Process Hazard Analysis and Keeping It Relevent

Process hazard analysis (PHA) is the cornerstone of good Process Safety Management (PSM). Sure! It should be extremely detailed and designed to examine and address potential hazards associated with handling highly hazardous chemicals. In your respective industrial sectors..are you truly covered? 

A good PHA will form part of your plant’s decision making about improving safety and reducing the major accident consequences associated with hazardous chemicals.

To simplify, its targeted at looking at : Fires/Explosions/Releases of toxic or flammable chemicals/Major spills of hazardous chemicals

By focusing on : Plant Equipment/Instrumentation/Utilities/ Human actions and external factors that might affect the process

The common pitfalls of PHA is the misunderstanding of the impact cumulative changes brings. Typically revalidated every 5 years this might be a process safety engineer's greatest nightmare. This is not the sweet spot!  But merely the guideline for maximum deviation. As clever engineers we understand a major change or many little changes may indeed affect the basis of safety in your process. Anything from the introduction of new piece of equipment or chemicals to the elimination of existing equipment or any change that could introduce a new hazard may trigger the need for an early study. How about the changes in your organizational structure where operational risk may be impacted? This seems like a fine art of what is overboard and what remains under the carpet.

Behold!!

In truth you want your cake and you will damn well eat it. In engineering terms that means, a rigorous study (HAZOP or suitable relevent risk tool) with a slice of checklist

https://www.aiche.org/sites/default/files/docs/embedded-pdf/0113_Safety_Preprint.pdf

The Idiot's Guide of What your PHA should assess

After you’ve picked your poison (err methodology), a good PHA addresses the following (paraphrased from various sources)

1. The hazards of the process
2. Incident and Near Miss History :The identification of any previous incident that had a likely potential for catastrophic consequences. How much does your reporting culture influence the iceberg effect. Is what you know truly what happened?
3. Engineering/administrative controls related to hazards, eg. detection methods for early warning of chemical releases (Acceptable detection methods might include process monitoring and control instrumentation with alarms, and detection hardware such as hydrocarbon gas detectors)
4. Consequences of failure of engineering and administrative controls (as a Chemical Process Engineer I would like to think my design never fails)
5. Facility siting (the location of various components within the facility)
6. Human factors (A topic on its own)
7. A qualitative evaluation covering the range of possible safety and health effects on employees stemming from control failures in the workplace.

Simple right? Yet process safety incidents continue to rise in industry. As withs scrutiny of most major incidents a combination of poor Process Safety Culture and Poor Hazard identification (PHA) led to major incident.

So how good is your PHA process?