By Jerry Lacatena
This brief article is a continuation of prior articles on Process Safety Management (PSM) to provide information on requirements to minimize unexpected or accidental releases of toxic, reactive, and hazardous chemicals listed in the OSHA PSM Standard (1910.11), and to prevent potential disasters from occurring. Information was largely obtained from the source documentation. This brief article focuses on process hazard analysis (PHA) and operating procedures pertinent to PSM.
The PHA is a thorough, systematic approach for identifying, evaluating, and controlling the hazards of processes involving highly hazardous chemicals. The company needs to perform an initial hazard evaluation on all processes covered by this standard. The PHA methodology selected must be appropriate to the complexity of the process and must identify, evaluate, and control the hazards involved in the process.
Companies should first determine/document the priority order for conducting PHA based on a rationale that includes such considerations as the extent of the process hazards, the number of potentially affected employees, the age of the process, and the operating history of the process. All PHAs must be updated and revalidated based on their completion date, at least every five years.
A number of PHA methods are available that companies may use as appropriate to determine and evaluate the hazards of the process being analyzed. These methods include:
Whichever method(s) are used, the PHA must address the following:
OSHA believes that the PHA is best performed by a team with expertise in engineering and process operations, and that the team should include at least one employee who has experience with and knowledge of the process being evaluated. Also, one member of the team should be knowledgeable in the specific analysis methods being used. The company must establish a system to address the team's findings/recommendations; ensure that the recommendations are resolved in a timely manner; and documented, maintained, and communicated to employees whose work assignments may be affected by the PHA recommendations or actions.
Written operating procedures must be established, consistent with the process safety information and equipment installed, and communicated to employees.
The procedures need to address at least the following elements:
It is vital that operating procedures be readily accessible to employees who work in, operate or maintain a process, and ensure that they reflect current operating practices, including changes in process chemicals, technology, and equipment. An annual review is needed to verify that operating procedures are accurate and appropriate.