Process hazard analysis (PHA), or evaluation, is one of the most important elements of the process safety management program. A PHA is an organized and systematic effort to identify and analyze the significance of potential hazards associated with designing, processing and handling of highly hazardous chemical. A PHA provides information that will assists employees in making decisions for improving safety and reduces the consequences of unwanted or unplanned releases of hazardous chemicals.
To evaluate previous process incident that had the potential to cause catastrophic consequences or impact in the workplace.
WHY DO WE NEED PROCESS HAZARD ANALYSIS?
Summarized by Darmawan Ahmad
To evaluate previous process incident that had the potential to cause catastrophic consequences or impact in the workplace
The incidents created a public awareness of the risks inherent to the process industry. Responding to public concerns, many governments enacting new and/or revising industry standards and government regulation/legislation to reduce these risks. Some of these major incidents that followed by PHA are:
• Phillips Pasadena, TX 1989 where 23 people killed
• Piper Alpha, UK 1988 where 165 peoples were killed
• Bhopal, India 1984 where 2500 people were killed
• Mexico City, 1984 where 500 people were killed
To evaluate the engineering design and/or administrative controls applicable to the process hazards and their interrelationships
Specifically, PHA is used to pinpoint weaknesses in the engineering design and operation of the facilities that could lead accidental toxic or flammable chemical releases, fire or explosions and major spills of hazardous chemicals. The PHA focus in equipment, instrumentation, mode of operation, utilities, human action (continuous and occasionally) and external factor that might affect the process.
To meet the Government and/or International Institution regulation and legislation
In the US, the Occupational Safety and Health Administration (OSHA) issued their standard for Process Safety Management (PSM) to protect worker safety, while the Environmental Protection Agency (EPA) issued its Risk Management Planning (RMP) program to protect public safety and the environment. One of the main elements of OSHA’s PSM program and the EPA’s RMP is the Process Hazard Analysis (PHA). OSHA’s PSM and EPA’s RMP mandate that all companies (in US and all around the world that have business connection to US companies) dealing with regulated chemicals of sufficient quantity must perform a PHA.
To obtain a global recognition and/or guaranteed the export oriented product
Due to restriction and limitation on imported food recently announced by Food and Drugs Agency (FDA), many food industries outside US must be certified and inspected by FDA before its product launched to the US market. By developing PHA (for food industry known as HACCP), at least one of FDA qualification has been fulfilled. In UK, the Food Safety (General Food hygiene) Regulation at 1995 introduced the legal requirement for all businesses to carry out a process hazard analysis of their food activities.
WHY SHOULD I REQUIRE PHA LEADER CERTIFICATION?
In the 1970’s, the US federal government proclaimed that asbestos was a major public health threat, and suddenly industry was inundated with asbestos abatement “experts” who know little about asbestos except that they could make money of it. In the 1990’s, federal and state mandates for PHAs have generated a similar abundance of “PHA experts”.
How can you identify a competent PHA leader when anyone how can spell HAZOP (Hazard and Operability Study, one of PHA methodologies) can claim to offer expert services? One answer is certification, such as that offered by the Process Safety Institute (PSI).
OSHA’s PSM regulation (29 CFR 1910.119) and EPA’s risk management program rule (40 CFR 68) require PHAs to be led by “knowledgeable” leader. In a series of workshops held in1992-1993 and sponsored by CMA, API, ORC, SOCMA and NPRA, an OSHA’s representative stated that “knowledgeable” is one who “has been trained by a recognized PHA expert and has satisfactory demonstrated understanding of that training”. This is similar to OSHA’s requirement for trained operator in paragraph (g) of 1910.119.
Beyond these regulatory issues, your company needs assurance of the competence of its PHA leader. After all, PHA leader will play an important role in protecting your company’s employees and assets in ensuring the well being of the general public.
These PHA leaders are the catalysts that combine your company’s technical expertise with efficient process hazard identification and evaluation techniques to produce practical suggestions for effectively managing the health, safety, environmental and economic risks facing your company.
Who would you prefer to have running your PHA: self-proclaimed expert whose only credentials are knowing what PHA stands for, or an expert who can cite documentation and independent verification of his or her expertise? Knowing your PHA leaders are certified increased your confidence that hazard are being appropriate and consistently controlled and that yours PHA will withstand regulatory scrutiny.
Process Safety Institute certification
Although some will argue that course attendance adequately meets the requirements for a knowledgeable PHA leader, it’s doubtful that one- or two-day classroom’s training season alone really produce competent leader. Certification can give you uniform criteria to decide whether a leader’s qualifications are sufficient for you. Thus, the Process Safety Institute has established a rigorous certification program to assure you that the individual:
1. Has the relevant background, education, and experience
2. Has completed a specific curriculum on the topic
3. Has passed a written examination on the regulatory requirements and the fundamentals of PHAs (including the most common hazard evaluation techniques such as HAZOP, what if?/checklist, and FMEA)
4. Has demonstrated understanding of the techniques in hands on classroom knowledge in at least two real analysis
For in house PHA programs, certification demonstrates that your organization is committed to PHA excellence as judged by an independent reviewer. And if your contract for PHA services, certification provide you some objective bases for comparing the apples, oranges and lemons who will responds to your requests. Ultimately, accident prevention is your primary goal (and meeting the expectations of regulators is an important secondary goal), so it is in your best interest to have evidence of the qualifications of your PHA leaders. With independently validated certification, you have that evidence.
A similar situation arose in 1995 when OSHA began to review the compliance audits of companies process safety management (PSM) program. The same need of having uniform criteria to judge the competence of your internal auditors and/or an auditing contractor’s qualifications applies. PSI offers a PSM auditor certification (using criteria similar to those for PHA leader certification) to help demonstrate that your programs reviewed by a knowledgeable auditor. And for those looking beyond the current regulation, PSI offers a quantitative risks analyst certification. Although certification is not explicitly required by current regulations, your insistence on using certified leaders would help enhance the quality of your PHA program, prevent more accidents, and improve your program’s capacity to withstand any third-party scrutiny.
CHOOSING THE BEST PHA EVALUATING METHOD
As part of OSHA’s PSM of Highly Hazardous Chemicals regulation (29 CFR 1910.119) and EPA’s Risk Management Program rule (40 CFR 68), regulators require PHA of chemical facilities. Industry groups such as API and CMA have also established safety standards that require PHAs. Many hazard evaluation (HE) methods (e.g., what if, checklist, HAZOP, FMEA, fault tree, event tree, human reliability analysis) are available to perform PHAs. Given the number of HE methods available and the variety of situation in which they may be applied, choosing the best HE method for a PHA is often a difficult task.
Unfortunately, a simple formula or algorithm for sselecting the best HE method for one particular problem does not exist. Fortunately, guidance is available: the AIChE CCPS’s Guidelines for Hazard Evaluation Procedures, Second Ed. Example with Worked Examples, provides some direction in selecting HE techniques. And, you find among most HE practitioners that expert judgment-based on their experience with several HE methods-guides their selection. The factor that should be consider in selecting an appropriate HE methods are:
Information available-When little information is available on a process, we choose a less structured HE method. For example, during the R&D phase of project, when system drawings and process conditions are unknown, we use what-if method or a general checklist for an HE. With plentiful information on a process, the number of the HE methods to choose from increases.
HE personnel requirement-Some HE methods (e.g., HAZOP, what if) require team to perform the analysis. For example we cann
ot HAZOP even well defined system with just one other team member. In this case we use a method that can perform by one person, such as FMEA or checklist.
Analyst Skills-Often, any of several HE methods may be appropriate for a particular analysis. In such cases, we recommend that analysts use HE method they (and their analysis team) are most comfortable with. If the lead analyst is unskilled, we suggest using the HAZOP method or an appropriated detailed checklist.
System complexity-Most HE method focus o finding singles failures that potentially could lead to serious accidents. For highly complex, highly redundant system, multiple failures must usually occur to create a serious accident condition. For this kind of problem we find fault trees and event trees are usually the most appropriate HE methods.
Previous HE studies-Although, HE methods are designed to identify and evaluate hazards, they each use a different approach. The same analysis team analyzing the same system of second time with a different HE method often identifies a few new causes of potential accidents. Thus, if several HE methods are appropriate for analysis, we usually prefer to use a different HE method for second review of a system.
System type-Any HE method can be applied to any system. However, some HE methods (e.g., HAZOP) are more difficult than others to apply to electric power systems. For electric power system, we find the FMEA and fault tree methods usually work best.
Time available- Usually managers want it done yesterday. When little time is available to perform an HE, we lean towards selecting one of the “faster” HE methods. We find that checklists and what ifs tend to require less time than the others commonly used HE methods.
In selecting an HE method, you will have to consider several of these factors as well as the others (e.g. cost factor, regulatory requirements) we have not mentioned. But remember, the HE will be no better than the team (or individual) that performs it. No matter which HE method you select, the team must know the system being examined and must use accurate system information to produce highly quality HE.
REVALIDATING PHAs TO COMPLY WITH EPA’s RMP RULE
If your company is like many others, 5 years ago you began performing PHA to meet OSHA’s PSM regulation. Now, as you face revalidation of your initial PHAs for the PSM regulation, EPA 1996 rule regarding RMP may add some new considerations to your revalidation program. To satisfy EPA, your PHAs will need to consider stationary source siting, offsites consequences, and previous incidents that impacted or could have impacted public safety or the environment.
Although the PHA requirements in the OSHA and EPA regulations are similar, there are distinct differences. These differences are dictated by each agency’s different-mission. OSHA’s charges is to protect workers, EPA directive is to protect the public and the environment.
The upshot of these different goals is that OSHA’s regulation could be interpreted to exclude considerations of offsite impacts, whereas EPA’s rule makes their inclusion explicit. For Instance, the section of the PSM regulation on PHAs (specifically 1910.119(e)(ii)) states that PHA shall address “the identification of any previous incident which had a likely potential for catastrophic consequences in the workplace”. The analogous passage in the RMP rule deletes “in the workplace”, which broadens the considerations of this requirement. Other requirements similarly broadened in the EPA rule include considerations of (1) potential offsite effects of releases of regulated substances and (2) stationary source siting. Therefore, these issues must be considered to make a revalidated PHA adequate for EPA.
The purpose of revalidation
Before dealing with the additions the RMP rule makes to PHA revalidation requirements, we should quickly review the purpose and process of revalidation. The revalidation of a PHA is meant to elicit specific results.
When you complete a revalidation, you want to know three things:
• The PHA is consistent with the current process. This means that if changes have occurred in the process since PHA was performed it must be ascertained that they do not affect the result of the PHA. If they do, then the revalidation must address them. Modifications to the process surroundings should also be evaluated/considered to determine their effect on the PHA results
• PHA identifies known process hazard. The concern is whether any hazards have been introduced to the process by the addition of new substances or changes in the process configuration or its surrounding, as well as whether the previous PHA adequately addressed all known hazards (include hazards during start up and shutdown modes of operations)
• Ensures that engineering and administrative controls are adequate to control the hazards of the process. The intent is to verify that safeguards noted in the initial PHA are still satisfactory for the current process or have been appropriately modified to address change in the process. This should include consideration of emergency response capabilities
The broader applicability of EPA’s RMP rule does not affect these three basic purposes of a PHA revalidation. What EPA’s rule affect are the revalidation process.