Process safety management of highly hazardous chemicals (PSM)

Scope

PSM applies to those companies that deal with any of more than 130 specific toxic and reactive chemicals in listed quantities (See 1910.119 Appendix A, which contains the list); it also includes any Category 1 flammable gas (as defined in 1910.1200(c)) or a flammable liquid with a flashpoint below 100°F (37.8°C) on site in one location, in a quantity of 10,000 pounds (4535.9 kg) or more (with a few exceptions, as outlined in 1910.119(a)(1)(ii)(A) and (B)).

Exempted from the standard A few types of facilities and operations are exempt from PSM. The standard does not apply to any of the following:

• Retail facilities. OSHA will typically not issue PSM citations to retail facilities, as those facilities generally do not present the same degree of hazard as other PSM workplaces. In particular, current OSHA policy specifically prohibits issuing PSM citations to employers in the following North American Industry Classification System (NAICS) codes:
  • 424510 - Grain and Field Bean Merchant Wholesalers;
  • 424590 - Other Farm Product Raw Material Merchant Wholesalers; and
  • 424910 - Farm Supplies Merchant Wholesalers.
• Oil or gas well drilling or servicing operations.
• Normally unoccupied remote facilities. (This means that employees are not permanently stationed at the remote location. This includes those sites for which periodic visits by employees may be made on a scheduled basis. Examples could include pump stations located miles from the main establishment. Employees may be assigned to check on the station as needed. But, the remote location must be geographically separated from other facilities and employees such that employees would not be affected by an explosion, vapor cloud of toxic gas, or other consequence of an uncontrolled release at the remote site.)

Regulatory citations

• 29 CFR 1910.119 — Process safety management of highly hazardous chemicals (PSM), including Appendix A — List of highly hazardous Chemicals, toxics and reactives

Key definitions

• Atmospheric tank: A storage tank designed to operate at pressures from atmospheric through 0.5 pounds per square inch gauge, 3.45 Kpa.
• Boiling point: The boiling point of a liquid at a pressure of 14.7 pounds per square inch absolute (p.s.i.a.) (760 mm.). For the purposes of this section, where an accurate boiling point is unavailable for the material in question, or for mixtures which do not have a constant boiling point, the 10 percent point of a distillation performed in accordance with ASTM D-86-62 may be used as the boiling point of the liquid.
• Catastrophic release: A major uncontrolled emission, fire, or explosion, involving one or more highly hazardous chemicals, that presents serious danger to employees in the workplace.
• Facility: The buildings, containers or equipment which contain a process.
• Highly hazardous chemical (HHC): A substance possessing toxic, reactive, flammable, or explosive properties and specified by paragraph 1910.119(a)(1).
• Hot work: Work involving electric or gas welding, cutting, brazing, or similar flame or spark-producing operations.
• Normally unoccupied remote facility: A facility which is operated, maintained or serviced by employees who visit the facility only periodically to check its operation and to perform necessary operating or maintenance tasks. No employees are permanently stationed at the facility. Facilities meeting this definition are not contiguous with, and must be geographically remote from all other buildings, processes or persons.
• One Percent Rule: The rule OSHA uses to determine if a mixture contains a covered volume of hazardous chemical. OSHA uses a one percent concentration cut-off.
• Process: Any activity involving an HHC including any use, storage, manufacturing, handling, or the on-site movement of such chemicals, or combination. For purposes of this definition, any group of vessels which are interconnected and separate vessels which are located such that a highly hazardous chemical could be involved in a potential release are considered a single process.
• Replacement in kind: A replacement which satisfies the design specification.

Summary of requirements

Employers with covered processes must:

• Ensure employee participation in the process safety management program.
• Compile information about the process. The compilation of written process safety information is to enable the employer and the employees involved in operating the process to identify and understand the hazards posed by those processes involving highly hazardous chemicals. This process safety information must include information pertaining to the hazards of the highly hazardous chemicals used or produced by the process, information pertaining to the technology of the process, and information pertaining to the equipment in the process.
• Conduct adequate process hazard analyses. The type of method used needs to be analyzed thoroughly for compatibility with the process. After the initial PHA, employers must revalidate the analysis at least every five years.
• Implement safe operating procedures. Operating procedures describe tasks to be performed, data to be recorded, operating conditions to be maintained, samples to be collected, and safety and health precautions to be taken. The procedures need to be technically accurate, understandable to employees, and revised periodically to ensure that they reflect current operations.
• Conduct process safety training. All employees, including maintenance and contractor employees, involved with highly hazardous chemicals need to fully understand the safety and health hazards of the chemicals and processes they work with for the protection of themselves, their fellow employees and the citizens of nearby communities. Training conducted in compliance with 1910.1200, the Hazard Communication standard, will help employees to be more knowledgeable about the chemicals they work with as well as familiarize them with reading and understanding SDSs. However, additional training in subjects such as operating procedures and safety work practices, emergency evacuation and response, safety procedures, routine and non-routine work authorization activities, and other areas pertinent to process safety and health will need to be covered by an employer’s training program.
• Ensure process safety for contractors. Employers who use contractors to perform work in and around processes that involve highly hazardous chemicals, will need to establish a screening process so that they hire and use contractors who accomplish the desired job tasks without compromising the safety and health of employees at a facility.
• Conduct pre-startup safety reviews.
• Ensure integrity of process equipment. Equipment used to process, store, or handle highly hazardous chemicals needs to be designed, constructed, installed and maintained to minimize the risk of releases of such chemicals. This requires that a mechanical integrity program be in place to assure the continued integrity of process equipment. Elements of a mechanical integrity program include the identification and categorization of equipment and instrumentation, inspections and tests, testing and inspection frequencies, development of maintenance procedures, training of maintenance personnel, the establishment of criteria for acceptable test results, documentation of test and inspection results, and documentation of manufacturer recommendations as to meantime to failure for equipment and instrumentation.
• Ensure management of change process and procedures are adequate. To properly manage changes to process chemicals, technology, equipment and facilities, one must define what is meant by change. In this process safety management standard, change includes all modifications to equipment, procedures, raw materials and processing conditions other than “replacement in kind.” These changes need to be properly managed by identifying and reviewing them prior to implementation of the change. For example, the operating procedures contain the operating parameters (pressure limits, temperature ranges, flow rates, etc.) and the importance of operating within these limits. While the operator must have the flexibility to maintain safe operation within the established parameters, any operation outside of these parameters requires review and approval by a written management of change procedure.
• Investigate incidents per OSHA requirements. Incident investigation is the process of identifying the underlying causes of incidents and implementing steps to prevent similar events from occurring. The intent of an incident investigation is for employers to learn from past experiences and thus avoid repeating past mistakes. The incidents for which OSHA expects employers to become aware and to investigate are the types of events which result in or could reasonably have resulted in a catastrophic release. Some of the events are sometimes referred to as “near misses,” meaning that a serious consequence did not occur, but could have. Employers need to develop in-house capability to investigate incidents that occur in their facilities. A team needs to be assembled by the employer and trained in the techniques of investigation including how to conduct interviews of witnesses, needed documentation and report writing.
• Ensure emergency planning and response efforts are adequate.
• Establish a process safety compliance audit process. Employers need to select a trained individual or assemble a trained team of people to audit the process safety management system and program — at least once every three years. A small process or plant may need only one knowledgeable person to conduct an audit. The audit is to include an evaluation of the design and effectiveness of the process safety management system and a field inspection of the safety and health conditions and practices to verify that the employer’s systems are effectively implemented. The audit should be conducted or lead by a person knowledgeable in audit techniques and who is impartial towards the facility or area being audited. The essential elements of an audit program include planning, staffing, conducting the audit, evaluation and corrective action, follow-up and documentation.