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:
The report will include a title page, table of contents and pertinent documentation specific to site needs.
The purpose of this section is to provide management with an overview of the report including scope, methodology, significant findings and the most important recommendations. If risk ranking is used in the PHA this section should summarize those discovered scenarios of the highest risk, if any. This section answers the basic questions of Who, What, Where, When, and How; much like the lead paragraph in a news story. It is generally limited to about one or two pages in length. In most cases this section is written last after the report has been drafted.
This section begins with a description of what this report is addressing including a short process description referencing pertinent detailed process safety information such as the operating procedures, process flow diagrams, piping and instrumentation diagrams and material safety data sheets for the process chemicals. For team-based studies the report must include a table listing the team members as well as an indication of their specific expertise such as plant operator or plant mechanic. The diversity of the team composition is an important OSHA PSM auditing point with specific requirements that the team include people with process knowledge. This section introduces the report by describing the contents to follow.
Scope and Objective
The process scope and limitations are provided in this section as well as the study objectives such as meeting the requirements of the OSHA PSM regulation or corporate or site process safety standards or goals. Include in the scope if this study targets multiple issues such as safety, environmental, business, and operability or only safety issues (i.e. what are the limitations of the scope). Describe specific guidelines used to specify consequence levels and liklelihood ratings. Describe how safeguard reliability was considered. References for the scope can be made to applicable process description documentation in the appendices, but scope limitations should be specified in this section. A listing can be made of the modes of operation included in the PHA such as startup, shutdown, emergency shutdown, routine operation and non-routine activities. Describe how utilities were considered as utilities are an important source of common fault causes for process upset scenarios.
In this section a short description of the process under study should be provided including pertinent equipment descriptions with reference to more detailed documentations. Equipment descriptors should include materials of construction, capacity and design parameters such as pressure or temperature limitations. Safety critical material properties such as toxicity, corrosivity, flammability, chemical compatibility and reactivity should be discussed in a general way so that the reader is better able to understand safety issues. This section should include a simple block-flow diagram showing how equipment is connected. Safety critical elements should be included such as local exhaust ventilation, emergency relief devices and systems and safety instrumented systems (interlocks).
This section is most commonly of the “boiler-plate” nature and describes the methods used to analyze the process in this particular PHA and identify hazards. OSHA approved methods such as Checklists, What-If, What-If/Checklist, Failure Mode and Effects Analysis, or HAZOP are typically described in this section. It is recommended that some discussion be included of why the selected method is applicable to this PHA with supporting references to the Process Safety Information (PSI). If a risk assessment technique was applied in the PHA it should be described, including pertinent consequence descriptors and likelihood levels. This section should also describe the risk rankings (based on appropriate risk tolerance levels) as well as actions required for each risk ranking, as well as a proposed schedule for closure. In this section the team participants are listed with their experience and titles.
Findings and Conclusions
This section should include all of the most important team findings from the PHA. Action items may include specific follow-up assignments, most commonly departments, although individuals may be specified. Action items should include enough detail so that they stand alone and responsible parties can clearly discern the teams’ concerns. Unless a code or standard has been breached use the word “consider” ahead of action items so that the responsible party can contemplate alternate solutions to address the issue and is not put in a corner with no ability to consider appropriate alternates to provide equivalent risk management. It is not the PHA team’s responsibility to “redesign” the process at the PHA table.
The Appendices should include:
• All PHA worksheets edited by the PHA leader and scribe and approved by the PHA team
• A complete action item listing with enough detail to allow those responsible for closure to understand the issue and make appropriate responses. Follow the independent reader rule (6-month rule) … “include enough detail in each recommendation so that you can grasp the issues after a time delay without additional documentation study or conversations with team members.”
• Process Safety Information References (include date and issue of materials) such as:
• Equipment files on those items within the PHA scope
• Safety Datasheets, SDs for all process chemicals and utility materials
• The Process Flow Diagram and written process description (often from the operating manual)
• Standard Operating Procedures (SOPs)
• Standard Operating Conditions (SOCs)
• Piping and Instrumentation Diagrams (P&IDs), if applicable to scope
• Process material and energy balances
• Listing of study “nodes” or other process subdivisions. This could be supplemented with marked-up P&IDs.
It is important that the PHA referenced documents are listed so that future revalidation efforts can be made from the proper perspective, considering process change.
In summary, make sure that a formal report exists on PHA efforts beyond the PHA worksheets such that a report reader will easily grasp the important hazards associated with the process and understand the path forward to ensure appropriate risk management. Your PHA report should then be ready to stand the test of time, revalidation and auditing.
David E. Kaelin, Sr., B.S.Ch.E., is a Senior Process Safety Specialist at Chilworth Technology. Mr. Kaelin has more than 25 years of experience in the specialty chemical manufacturing industry and 15 years specializing as a Process Safety Engineer. He has participated in the design and construction of numerous chemical processing facilities and provided support and training in all areas of PSM. As a Process Safety Engineer he has led process hazard analysis, risk assessments and facility siting reviews. At the corporate level he has created and taught courses in PSM and hazard recognition methods. Mr. Kaelin is an expert in the application of hazard recognition techniques including: HAZOP, FMEA. What-If, Fault Tree Analysis, Risk Screening and Checklist. He is an active member of AIChE, and NFPA. For more information, contact Chilworth Technology at www.chilworth.com or email email@example.com.