Health & Safety Insights

When you think of catastrophic releases of toxic, reactive, flammable, or explosive chemicals, you might think of their impacts on a community or the environment. Yet, employees who work at the facilities that experience these releases can be at risk too.

The Occupational Safety and Health Administration (OSHA) has a mission to ensure that America’s workers have safe and healthful working conditions. The agency’s Process Safety Management of Highly Hazardous Chemicals (or PSM) standard at 29 CFR 1910.119 aims to protect employees by preventing or minimizing the consequences of these incidents involving processes with highly hazardous chemicals.

Real-world incidents

The event that prompted the PSM standard occurred on December 2, 1984, in Bhopal, India. A cloud of methyl isocyanate gas escaped from a chemical plant and spread to the community near the plant. This resulted in the death of approximately 4,000 residents and injured thousands. In addition, 8,000 more died in the two weeks afterwards. Over 550,000 people experienced long-term exposure-related illnesses.

After the Bhopal incident, OSHA determined that it was necessary to investigate U.S. producers and users of methyl isocyanate. However, the investigation found that OSHA standards did not cover chemical industry process hazards or address employee protection from large releases of hazardous chemicals, not just methyl isocyanate.

The agency’s work intensified after an August 1985 incident that occurred at another facility in Institute, West Virginia. A cloud of toxic chemicals (aldicarb oxime and methyl chloride) used to manufacture pesticides was released. Six employees were injured, and more than a hundred residents were sent to the hospital.

PSM rulemaking

After more study, OSHA determined that available evidence supported the need for a rulemaking. On July 17, 1990, OSHA proposed a standard for the management of hazards associated with processes that use highly hazardous chemicals. The intent was to ensure those employees working with these processes had a safe and healthful workplace.

Four months later, the Clean Air Act Amendments (CAAA) were enacted into law (November 15, 1990). The new law required OSHA to issue a chemical process safety standard to prevent accidental releases of chemicals that could pose a threat to employees. OSHA quickly finalized its rulemaking on February 24, 1992, after careful examination of the CAAA and comments received. The rule created 29 CFR 1910.119 and appendices A through D.

Today’s PSM standard structure

The framework of the PSM standard remains largely unchanged since OSHA issued it over 30 years ago:

• Purpose
• (a) Application
• (b) Definitions
• (c) Employee Participation
• (d) Process Safety Information
• (e) Process Hazard Analysis
• (f) Operating Procedures
• (g) Training
• (h) Contractors
• (i) Pre-Startup Safety Review
• (j) Mechanical Integrity
• (k) Hot Work Permit
• (l) Management of Change
• (m) Incident Investigation
• (n) Emergency Planning and Response
• (o) Compliance Audits
• (p) Trade Secrets
• Appendix A: List of Highly Hazardous Chemicals, Toxics and Reactives (Mandatory)
• Appendix B: Block Flow Diagram and Simplified Process Flow Diagram (Nonmandatory)
• Appendix C: Compliance Guidelines and Recommendations for Process Safety Management (Nonmandatory)
• Appendix D: Sources of Further Information (Nonmandatory)

Rather than setting specific engineering requirements, the standard emphasizes the application of documented management controls. By using the controls, employers address the risk associated with handling or working near highly hazardous chemicals. Employers must thoroughly consider all facets of a process, as well as the involvement of employees in that process.

Implementing the standard takes extensive paperwork. This ensures that employers collect the information they need to control and reduce injuries, illnesses, and fatalities in these workplaces. After all, they have the potential for highly hazardous chemical catastrophes.

Once a comprehensive PSM program is developed and implemented, it needs to be maintained and updated as changes occur. Be aware that several recurring activities are required:

• The process hazard analysis must be updated and revalidated at least every five years;
• The frequency of inspections and tests of process equipment must be consistent with manufacturer recommendations and good engineering practices, but more frequent if determined to be necessary;
• Refresher training of each employee involved in operating a process is required at least every three years and more often if necessary; and
• A compliance audit must be conducted by a person knowledgeable in the process and certified by the employer at least every three years.

PSM applicability

OSHA estimates that about 9,000 establishments and 12,000 processes fall under the PSM standard. The standard:

• Mainly applies to manufacturing industries — particularly, those pertaining to chemicals, transportation equipment, and fabricated metal products.
• Affects other sectors such as natural gas liquids; farm product warehousing; electric, gas, and sanitary services; and wholesale trade.
• Also applies to explosive and pyrotechnic manufacturing facilities covered under other OSHA standards.

While these industries are commonly affected, PSM applicability is not determined by industry type. Rather, it hinges on the processes, chemicals, and quantities present. The PSM standard applies to:

• A process that involves any of the more than 130 specific toxic and reactive chemicals in listed quantities; or
• A process that involves flammable liquids and gases in quantities of 10,000 pounds or more, with some exceptions.

The term “process” means any activity involving a highly hazardous chemical including using, storing, manufacturing, handling, or moving such chemicals at the site, or any combination of these activities. Any group of vessels that are interconnected, and separate vessels located in a way that could involve a highly hazardous chemical in a potential release, are considered a single process.

Even when the applicability criteria are met, the standard does not apply to:

• Retail facilities,
• Oil or gas well drilling or servicing operations, or
• Normally unoccupied remote facilities.

Keys to remember

OSHA issued the PSM standard in 1992 to protect employees from the hazards associated with processes that use highly hazardous chemicals. Today, the standard has largely the same framework as it did back then, with 16 paragraphs and 4 appendices. In addition, many provisions require documentation.

The PSM standard applies to those employers with processes that involve any of the more than 130 specific toxic and reactive chemicals in listed quantities. It also applies to processes that involve flammable liquids and gases in quantities of 10,000 pounds or more. The term process is defined in the standard.