PT Notes
EPA RMP Rule 2024 Amendments - STAA Safeguard Implementation
PT Notes is a series of topical technical notes on process safety provided periodically by Primatech for your benefit. Please feel free to provide feedback.
The amended rule requires that Program 3 Process hazard Analysis address STAA, which involves the application of the hierarchy of controls for process safeguards.
EPA believes that in some circumstances, relying solely on voluntary implementation of STAA measures is not reasonable and would be inadequate to prevent accidents ”to the greatest extent practicable”, as required by the CAA. This is particularly true when safeguards are identified and generally deemed practicable, but are not implemented. EPA believes that a reasonable decision to not implement such safeguards at a facility must be supported with a comprehensive review of factors such as cost, risk reduction, risk transfer, employee input, and engineering that concludes the technology is not practicable contextually.
While EPA continues to believe that the source has the primary expertise and resources to weigh decisions on process design, process safety and accident prevention, EPA is concerned that controlling hazards and adopting reasonable safety measures and layers of protection necessary to keep the public and environment safe from chemical releases based on reasoned, documented decision-making do not always occur. EPA notes that in CSB investigations oif several recent process safety incidents, identified safeguards that should have been in place to prevent or mitigate major accidents were not present.
EPA acknowledges that requiring facilities to implement IST can involve extensive changes to a facility’s process, depending on the IST, especially if it involves substitution of alternative chemicals and/or major process redesign to existing processes. EPA notes that nothing in the amended RMP rule forces the adoption or abandonment of any technology or design.
EPA believes that measures lower on the hierarchy of controls, passive, active and procedural measures, when implemented appropriately, can be used to help operate a hazardous chemical process safely and can also reduce hazard risks of that process. When compared with IST, these measures could also more likely be added, modified, and improved after the initial design or operation of a facility.
EPA is requiring implementation of passive measures as a priority rather than active and procedural because it is the next highest level below IST on the hierarchy of controls and the most reliable in comparison to active and procedural safeguards, as they reduce risks without human, mechanical, or other energy input.
EPA recognizes that passive safeguards may not exist or may not be practicable for a variety of reasons and other safeguards may be needed to cover gaps in process safety risk reduction. EPA also recognizes that a passive measure may be even more effective when applied appropriately with other measures. The concept of layers of protection acknowledges that individual safeguards are not completely reliable or effective, and thus multiple safeguards (‘‘layers’’) may be needed to minimize the chances of an initial fault propagating to a full-blown incident with potential for harm.
EPA states that the amended RMP rule provides the facility owner or operator with the flexibility to assess and potentially implement IST, passive measures, or a combination of active and procedural measures to reduce risk associated with a process. EPA notes that the rule also provides flexibility by allowing for consideration of factors such as chemical formula specifications for toll manufacturers, the potential for risk transfer, supply chain limitations, and the need to address security implications of any change when assessing whether to reject particular passive measures.
Facilities that have already implemented passive measures or an equivalent level of risk reduction should document their implementation in their next PHA, determine whether there is additional information that should be considered in their STAA, and continue to consider additional passive (or equivalent) measures during subsequent PHA revalidation cycles.
EPA notes that not all damages from process safety incidents accrue to the source responsible for the accident. For example, offsite impacts such as injuries, sheltering in place events, evacuations, environmental damage, and so on are experienced by people in the community surrounding a facility. There is a market failure because these costs are external to the facility and firms do not have an appropriate level of incentive to prevent them. Catastrophic events impose extensive burdens on people external to the source responsible for the accident. Moreover, these incidents are low probability, high consequence events that are difficult for owners and operators to assess. Therefore, it may be unreasonable to rely primarily on sources to make the ultimate decision on whether to adopt any measures at all. EPA states that the standard adopted in the rule for sources presenting elevated risks to communities, wherein EPA mandates adoption of at least one passive measure at the facility, or an inherently safer technology or design, or a combination of active and procedural measures equivalent to or greater than the risk reduction of a passive measure, is intended to reasonably addresses the potential market failure that would lead to less implementation than would be necessary for risk reduction.
EPA believes there is an overemphasis on initial costs leading to less consideration of safer, reliable methods to reduce process risks. EPA notes that CCPS’s 2019 ‘‘Guidelines for Inherently Safer Chemical Processes, A Life Cycle Approach’’ discuss the tradeoff of initial and operating costs of implementing different STAA measures. CCPS indicates that while inherently safer and passive measures do tend to have higher initial capital costs, operating costs are usually lower than those for other measures. For active measures as compared to inherently safer and passive measures, reliability is typically lower, and complexity is greater. Operating costs are also actually likely to be the greatest for active measures. While procedural measures are most often tempting solutions due to their initial very low capital cost and typically lower complexity, they are also often the least reliable and should be considered only after other solutions have been explored. EPA believes that passive measures, or active / procedural equivalent measures, that reduce risk and are practicable should be implemented.
EPA is not requiring formal practicability assessments (as is now required for IST) for passive, active, or procedural measures. Since evaluation of passive, active and procedural measures has been a part of the RMP rule, leading to implementation of some, it is expected that the determination of their practicability already occurs.
In order to ensure that the assessment determining a measure is not practicable complies with the definition in the amended RMP rule, sources are required to document this conclusion to the implementing agency’s satisfaction. This requirement is intended to help ensure that costs alone are not the sole factor in determining practicability.
EPA believes that safer design and technology information and lessons learned are continually being generated, and facilities should integrate such updated information to help prevent accidents.
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Disclaimer: This PT Note provides Primatech’s interpretation of regulatory requirements. The actual regulatory requirements can be found at: https://www.epa.gov/rmp
