The pharmaceutical industries often conduct batch reactions using toxic or flammable materials. In many cases, complex chemical reactions are carried out with significant energy release. Such processing can cause fire, explosion or runaway reaction hazards that could threaten personnel and facilities.
Regardless of the method used to identify hazards and manage risk (HAZOP, What-If, Checklist, etc.), it will only produce appropriate findings if it is grounded in adequate Process Safety Information and documentation. Although many pharmaceutical operations are not covered by the Occupational Safety and Health Administration’s PSM (Process Safety Management) program, the regulation is an effective guidance for PSM activities. In the pharmaceutical industry, PSI must include chemical reaction hazard information as well as the flammability and toxicity of all reactants, intermediates and products.
An essential part of process safety management is the documentation of the process hazard analysis, PHA. It has been said that “what is not documented has not occurred or does not exist.” In the auditing of PHAs of both OSHA PSM covered and non-OSHA covered processes by this author, one finding has been common; the spreadsheet-like worksheets created during the PHA team studies have been often the only documentation of the effort. Worksheets alone are insufficient to meet the standards of either OSHA or the needs of chemical process industries (as indicated in literature published by the American Institute of Chemical Engineers (AIChE), through the Center for Chemical Process Safety, CCPS). Although the OSHA PSM regulation does not specify the need or format of a formal PHA report, it does require documentation of the effort. In addition, under RAGAGEP (Recognized and Generally Accepted Good Engineering Practices) OSHA may interpret the quality of documentation against the CCPS recommendations. Does the PHA report pass the “six-month rule” i.e. if you read it in six months time will you understand what the hazards and risks are and what safeguards are key to safe operation? Is there sufficient detail?
The OSHA PSM regulation requires that a PHA and subsequent re-validations be kept for the life of the process. In addition, all follow-up activities in regards to the closure of PHA recommendations must be documented and the documentation retained. These retention practices are recommended for non-OSHA processes as well. Such retention is important to the periodic PHA revalidation process and the management of process changes to ensure that new, un-assessed hazards are not introduced. In one case I conducted revalidations at a site where essentially no closure activity or documentation of closure had been completed for the PHA recommendations in the subsequent six years since the initial study. In that case, I found that although most items had in fact been completed no closure report or other documentation had been issued.
PHA REPORT ELEMENTS
Facility siting considerations are an OSHA PSM required PHA element. PHA reports must include a description of how facility siting was considered, safety critical findings, and recommendations for follow-up activities. Siting checklists such as those published in CCPS guidebooks are good tools for siting considerations, but the checklists alone may not provide enough detail of findings. It is possible that, for some highly hazardous materials, additional efforts such as consequence analysis and risk analysis will be required and their results documented or referenced in the PHA report. For example: In case of a material release, have all possible consequences been considered such as toxic effects, pool fire, jet fire, vapor cloud explosion or boiling liquid expanding vapor explosions. Modeling of such effects can be complex and may require specialists input. It is recommended that dedicated paragraphs be included in the PHA report for these additional subjects. I have worked on process designs where detailed dispersion modeling had been performed on possible relief system discharges in order to justify the suggested containment systems. During the PHA, concerns had been raised but details regarding the degree of hazard were unavailable and proposed (and expensive) redesigns needed to be justified.
Human factors are another OSHA PSM required element within a PHA and like facility siting, human factors are often covered by a specific checklist such as those published in CCPS guidebooks. In addition, human factors should be specifically considered in the PHA worksheets under causes of process safety hazard scenarios regardless of how the scenario is identified. Experienced PHA leaders are a significant help in this effort. Consistent use of phrases such as “human error of omission” or “human error of commission” should be used throughout the hazard assessment worksheet (under cause column) in order to demonstrate and document consideration of theses human factors involving operators, mechanics, engineers, management or others. Procedural HAZOPs and Job Safety Analysis are two additional PHA methods that should be considered to develop effective human factors hazard scenarios. These studies could be follow-up activities recommended by the overall process PHA study.
In identifying and assessing process hazards in a PHA, OSHA expects hazards associated with the locations of buildings and employees, as well as the discharge from emergency relief to be specifically addressed. Regardless of hazard assessment method applied, the PHA report should indicate where these hazards exist and how they are managed.
PHA REPORT FORMAT
Numerous references describe formats that should be used for a technical report. The PHA report should follow this general style, as it is reporting on a scientific method used to assess process hazards. The important sections for a PHA report are discussed below: