Monday, July 28, 2008

Process Safety Management ) PSM)

By : Ian Sutton
Process Safety Management (PSM) programs are used to ensure the safe design and operation of process facilities such as chemical plants, oil refineries, gas plants and offshore platforms. PSM programs focus on major process-related events such as fires, explosions and the release of toxic chemicals. They do not generally address traditional occupational safety issues, such as trips and falls.
Regulations and Standards
Thefirst PSM regulations were developed in response to a number of serious accidents, such as that at Bhopal, India, that occurred in the 1980s. In the United States the most important PSM regulation was 29 CFR 1910.119 from the Occupational Safety & Health Administration (OSHA) [1]. It was introduced in the year 1992. In 1996 the regulatory scope of PSM was extended by the Environmental Protection Agency (EPA) to include the environment and public safety [2]. Some states have their own PSM rules. These include:
New Jersey's Toxic Catastrophe Prevention Act (1986) [3];
Delaware's Extremely Hazardous Substances Risk Management Act (1989) [4]; and Nevada's Chemical Accident Prevention Program (CAPP) [5] 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 [6].

Process Safety vs. Occupational Safety
It is crucial to distinguish between process safety and occupational safety. The "Baker Panel report" [7] that was written following the tragic 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 and the implementation of the Group-wide driving standard 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 1, 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 move 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 vents may not reduce the chance of a major accident, and may even lead to a false sense of complacency.
Figure 1The Safety Triangle

Elements of PSM

Process Safety Management [8] [9] programs are typically divided into a set of between twelve and twenty inter-related elements. The list below is provided by OSHA.
Employee Participation
Process Safety Information
Process Hazards Analysis
Operating Procedures
Prestartup Safety Review
Mechanical Integrity
Hot Work
Management of Change
Incident Investigation
Emergency Planning And Response
Compliance Audits
Trade Secrets The elements link with one another. For example, an engineer may wish to change operating conditions. First he or she must use the Management of Change system (element 10); which may require that he or she conduct a HAZOP; then he needs to update the Process Safety Information (element 2); he or she must then update the Operating Procedures (element 4); train the operators on the new conditions (element 5); carry out a Prestartup Safety Review (element 7) before running at the new conditions; and finally update the audit program (element 13).
As PSM programs have developed, so they have moved beyond basic regulatory compliance into areas such as improving reliability and understanding company culture. As an example of this change, a recent Center for Chemical Process Safety publication [10] lists the twenty elements shown below.
1. Process Safety Culture
2. Compliance
3. Competence
4. Workforce Involvement
5. Stakeholder Outreach
6. Knowledge Management
7. Hazard Identification / Risk
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
Occupational Safety & Health Administration (OSHA)
NewJerseyToxicCatastrophePrevention Act
DelawareExtremelyHazardousSubstancesRiskManagement Act
API RP 750
Baker Panel Report
Sutton, Ian S. Process Safety Management. Sutton Technical Books. 2007.
CenterforChemicalProcessSafety(CCPS) books
Center for Chemical Process Safety. Guidelines for Risk Based Process Safety. 2007.

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