PT Notes
The Importance of a Charter for PHA Revalidation
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A charter, that is the purpose, scope and objectives, should be defined and documented for every PHA study. It provides an essential roadmap for study teams to follow in performing studies and its importance cannot be overemphasized.
The charter for a revalidation PHA study has some important modifications from the charter for an initial PHA study. It should not simply be carried over from the previous study. While some aspects of the charter may be the same, others will be different.
In the case of the study purpose, there may be possible additional purposes, such as supporting a design modification or confirming that action items from the previous PHA reduce risk to tolerable levels and do not introduce new hazards.
In the case of the study scope, process boundaries may need revision, for example owing to the installation of an additional storage tank.
Additionally, as part of the scope statement, the charter must specify items to be studied that are specific to PHA revalidation, including:
- Process changes that have occurred since the previous PHA study was updated, e.g. added equipment or modified procedures.
- New requirements, e.g. new or updated industry standards or government regulations, such as modifications to EPA’s RMP rule.
- Omissions and deficiencies in the previous PHA study, e.g. no consideration of human factors or facility siting.
- Incidents that have occurred in the process or similar processes since the previous PHA study, including near misses.
- Open recommendations from the previous PHA study. They may need to be carried forward into the revalidation study.
- New technology and information, e.g. changes in the process technology ,such as the introduction of automation, or increased knowledge about the process, such as new reactivity data.
In the case of the study objectives, there may be additional hazards to address, for example, from the introduction of a new chemical to the process that poses a new hazard. Of course, the same types of hazards and consequences that were addressed in the previous PHA will apply unless process changes have eliminated them.
Writing a charter is an essential part of preparing for PHA studies. The charter for revalidation studies must reflect all aspects of the process that have changed since the previous PHA study. Owing to its importance, the charter should be recorded as part of the study documentation so that it is available for inspection by stakeholders.
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