Process Safety Management

• It must involve a chemical or have chemical process involvement;
• It must be above a minimum reporting threshold; 
• It must occur at a process location; and
• The release must be acute, i.e., it must occur over a short period of time.
  

Occupational Safety

Process Safety / Occupational Safety

It is particularly important to distinguish between process safety and occupational  safety. The Baker Panel report, written following the explosion at BP's Texas City refinery in 2005 stated,

BP's executive management tracked the trends in BP's personal safety metrics, and they understood that BP's performance in this regard was both better than industry averages and consistently improving. Based upon these trends, BP's executive management believed that the focus on metrics such as OSHA recordables . . . were largely successful. With respect to personal safety, that focus evidently was effective. BP's executive management, however, mistakenly believed that injury rates, such as days away from work case frequency and recordable injury frequency, were indicators of acceptable process safety performance. While executive management understood that the outputs BP tracked to monitor safety were the same as those that the industry generally monitored, it was not until after the Texas City accident that management understood that those metrics do not correlate with the state of process safety.

The distinction between occupational and process safety means that safety triangles, such as that shown in Figure 2, should be used with care. The basic idea behind the use of such triangles is that major events such as fatalities, large environmental spills and serious financial losses occur only rarely. By contrast, near misses and low consequence events are much more common and can be seen as being precursors to the more serious events. Using the ratios shown in the sketch, it is assumed that if a facility can move from 10000 to 9000 near misses, then the number of fatalities will be reduced from 10 to 9, and the chance of a catastrophe will also go down by 10%. However, fatal and catastrophic events are often caused by process safety deficiencies. Therefore improvements in occupational safety that reduce the number of low consequence events may not reduce the chance of a major accident, and may even lead to a false sense of complacency.

Figure 2
The Safety Triangle

Consideration should be given to adjusting Figure 2 to look like Figure 3.

Figure 3
Modified Safety Triangle

Regulations and Standards

The first onshore PSM regulations were developed in response to a number of serious accidents that occurred in the 1980s, such as the release of toxic vapors at Bhopal, India that killed thousands. In the United States the federal regulation 29 CFR 1910.119 Process safety management of highly hazardous chemicals was published in the year 1992 by the Occupational Safety & Health Administration (OSHA). In 1996 the Environmental Protection Agency (EPA) established its Risk Management Program (last updated 2004) which includes the environment and public safety within the scope of PSM. In addition, some states brought out their own PSM rules. These include:

• New Jersey's Toxic Catastrophe Prevention Act (1986);
• Delaware's Extremely Hazardous Substances Risk Management Act (1989); and
• Nevada's Chemical Accident Prevention Program (CAPP).
  
  

The offshore oil and gas industries have their own approaches to Process Safety Management; most of them either fall under the API's Recommended Practice 75 or the Safety Case system. The recently announced SEMS (Safety and Environmental Management System) rule from BSEEas a structure very similar to that of PSM.

Various professional societies have also created standards and guidance for Process Safety Management programs. An example is the American Petroleum Institute (API) Recommended Practice 750 Management of Process Hazards.

Elements of PSM

Process Safety Management programs are typically divided into a set of between twelve and twenty inter-related elements. The list below is from the OSHA reference provided above. Each of these elements are described in detail in the book Process Risk and Reliability Management.

• Employee Participation
• Process Safety Information
• Process Hazards Analysis
• Operating Procedures
• Training
• Contractors
• Prestartup Safety Review
• Mechanical Integrity
• Hot Work
• Management of Change
• Incident Investigation
• Emergency Planning and Response
• Compliance Audits
• Trade Secrets

An updated list from the Center for Chemical Process Safety (CCPS) is shown below.

1. Process Safety Culture
2. Compliance
3. Competence
4. Workforce Involvement
5. Stakeholder Outreach
6. Knowledge Management
7. Hazard Identification and Risk Management
8. Operating Procedures
9. Safe Work Practices
10. Asset Integrity / Reliability
11. Contractor Management
12. Training / Performance
13. Management of Change
14. Operational Readiness
15. Conduct of Operations
16. Emergency Management
17. Incident Investigation
18. Measurement and Metrics
19. Auditing
20. Management Review

The elements link with one another. For example, an engineer may wish to change operating conditions. First she must find out what the current operating limits are (element 6). The proposed change will then be put through the Management of Change system (element 13); which may require that a HAZOP be performed (element 7); then operating information (element 6), operating procedures (element 8) and training programs (element 12) must be updated. Before making changing conditions in the field a Readiness/Prestartup Safety Review (element 14) needs to be performed. Finally the updated program must be audited (element 19).

Features of Process Safety Management

Participation

PSM is not a management program that is handed down by management to their employees and contract workers; it is a program involving everyone. The key word is participation — which is much more than just mere communication. All managers, employees and contract workers are responsible for the successful implementation of PSM. Management must organize and lead the initial effort, but the employees must be fully involved in its implementation and improvement because they are the people who know the most about how a process really operates, and they are the ones who have to implement recommendations and changes. Specialist groups, such as staff organizations and consultants can provide help in specific areas, but PSM is fundamentally a line responsibility.

On-Going

PSM is an on-going activity that never ends; it is a process, not a project. Because risk can never be zero, there must always be ways of improving safety and operability. Process safety management cannot be viewed as being a one-time fix.

Non-Prescriptive

Process safety management programs are non-prescriptive which means that the regulations and other standards in this field generally provide very little detail as to what needs to be done. For example, the technical section of the OSHA PSM standard is only about ten pages long.

Basically, PSM rules say ‘do whatever it takes on your facility not to have accidents’. It is up to the managers and employees to determine how this should be done. There are no universally ‘correct answers’ as to what needs to be done to achieve a safe operation. What is appropriate in one location may or may not be appropriate in another. The PSM standards simply require that programs be in place, and that they be adhered to. (In this regard, PSM is similar to ISO 9000 and other quality standards, which also require that companies set their own standards, and then adhere to them.)

Performance-Based

Programs that are non-prescriptive are, of necessity, performance-based. This means that the only true measure of success is not to have upsets or accidents. Consequently, from a theoretical point of view, it is impossible to achieve ‘compliance’. The only truly acceptable level of safety is zero accidents. Yet, no matter how well run a facility may be a zero accident rate is a theoretically unattainable goal. In spite of the fact that many companies set a target goal of ‘zero accidents’, risk can never be zero, and accidents can always happen. Indeed, if a unit operates for long enough, it is certain  - statistically speaking - that there will be an accident. Hence, even though the stated PSM goal may be ‘zero accidents’, in practice, management has to determine a level for ‘acceptable safety’ and for realistic goals.