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PT Notes

Amendments to EPA's RMP Rule - Safer Technologies and Alternatives Analysis

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.

EPA has proposed several amendments relating to prevention program provisions. This PT Note addresses:

  • EPA’s proposed requirement for Program 3 regulated processes in NAICS codes 324 (petroleum and coal products manufacturing) and 325 (chemical manufacturing processes) that are located within 1 mile of another RMP-regulated facility with these same processes to consider and document the feasibility of applying safer technologies and alternatives (STAA) risk management measures applicable to eliminating or reducing risk from process hazards as part of their PHA.

  • EPA‘s proposed requirement that all facilities in NAICS code 324 using hydrofluoric acid (HF) in an alkylation unit consider safer alternatives, regardless of proximity to another NAICS 324- or 325-regulated facility.

Further details are provided below.

EPA notes that RMP facilities in the two selected sectors have been responsible for a relatively large number of accidents, deaths, injuries, and property damage and that implementation of safer technology and alternatives by these facilities in the chemical manufacturing and petroleum refining sectors may prevent serious accidental releases in the future. 

Current PHA requirements under the RMP rule include some aspects of the hierarchy of controls analysis. Program 3 processes are required to address process hazards using engineering and administrative controls. However, there is no explicit requirement for owners and operators to address inherent safety, which is the first tier of the hierarchy of controls. EPA is proposing to require the consideration of safer technology and alternative risk management measures that could eliminate or reduce risk from process hazards. In addition to engineering and administrative controls, owners and operators of facilities with Program 3 processes covered under this provision would have to consider the application of the following safer technology measures, in the following order: inherently safer technology (IST) or inherently safer design (ISD), passive safeguards, active safeguards, and procedural safeguards.

EPA does not intend to require facilities implement identified inherent safety measures. Instead, EPA is requiring evaluation of STAA as part of the PHA requirements in the rule and documentation of the feasibility of inherent safety measures based on more than cost alone, as well as employee involvement in the STAA evaluation. STAA summaries must be submitted to EPA for the purpose of technology transfer to other owners and operators to help them identify safer alternatives for their processes.

EPA believes facility owners and operators will adopt IST and other safer technology alternatives when it is practicable technically and economically and when the risk reduction is significant even in the absence of a mandate.

EPA is proposing that a facility's STAA team include, and document the involvement of, one member who works in the process and has expertise in the process being evaluated.

EPA is also proposing to include a more comprehensive practicability assessment, in addition to the STAA evaluation requirements as part of the PHA. As part of this analysis, owners and operators would be required to identify, evaluate, and document the practicability of implementing inherent safety measures, including documenting the practicability of publicly available safer alternatives. EPA intends for this process to be separate and additional to PHA requirements.

Although an owner or operator may choose not to implement a safer technology or design identified on account of its cost, EPA is proposing that the evaluation of practicability be first based on technological, environmental, legal, and social factors, with economic considerations evaluated last. EPA proposes that the practicability assessment be documented with the technological, environmental, legal, social and economic factors outlined, along with any methods or processes used to determine practicability.

''Safer technology and alternatives'' refers to risk reduction or risk management strategies developed through analysis using a hierarchy of process risk management strategies (or hierarchy of controls). In this context, the hierarchy of controls consists of controls that are inherent, passive, active, and procedural. STAA considers risk reduction measures in the order of the hierarchy. The owner or operator may evaluate a combination of risk management measures to reduce risk. By incorporating these requirements into PHA, EPA proposes to require facilities to address STAA in processes that already exist, rather than only during the design phase. The results of the STAA must be documented as part of the current PHA provisions, which require the owner or operator to document actions to be taken and resolution of recommendations.

EPA contends that the current 5-year revalidation schedule for PHA will give the owner or operator the opportunity to identify new risk reduction strategies, as well as revisit strategies that were previously evaluated to determine whether they are now practicable as a result of changes in cost and technology.

STAA includes considering IST or ISD, which refer to strategies that permanently reduce or eliminate hazards associated with the materials and operations of a process. The four major inherently safer strategies are: (1) substitution: replacing hazardous materials with less hazardous substances; (2) minimization: using smaller quantities of hazardous substances; (3) moderation: creating less hazardous conditions or using less hazardous forms or facility designs to minimize the impact of potential releases of hazardous materials or energy; and (4) simplification: designing facilities to eliminate unnecessary complexity and make operating errors less likely. Thus, IST / ISD eliminate, replace, or reduce the use of regulated substances or make operating conditions less hazardous or less complex.

Inclusion of IST / ISD in the RMP regulations is consistent with several CSB investigations that demonstrated that incidents could have been prevented or consequences mitigated by using IST/ ISD.

EPA is proposing to limit the applicability of the STAA provisions to sources in the petroleum and coal products manufacturing (NAICS 324) and chemical manufacturing (NAICS 325) sectors, located within 1 mile of another RMP-regulated 324 or 325 facility. EPA believes that while most sectors regulated under the RMP rule could identify safer technology and alternatives, sources involved in complex manufacturing operations have the greatest range of opportunities to identify and implement safer technologies and alternatives, particularly related to inherent safety. These sources generally produce, transform, and consume large quantities of regulated substances under sometimes extreme process conditions and using a wide range of complex technologies.

EPA is only requiring STAA in industries with the most frequent and severe accidents with offsite consequences. EPA has identified densely co-located refineries and chemical manufacturing facilities (i.e., facilities with processes in NAICS 324 and 324 within 1 mile of another facility with processes in these NAICS) as a class of facilities that present a heightened risk to nearby communities. The proximity of densely co-located refining and chemical manufacturing facilities creates a greater risk of an accident at one facility impacting safety at the nearby facility, thereby increasing the potential for a release at the second facility (a ''knock-on'' release). Communities in areas with such densely co-located petroleum refining and chemical manufacturing facilities face overlapping vulnerability zones and a heightened risk of being impacted by an accidental release relative to other communities. EPA believes that the heightened risk of community impacts presented by densely co-located refineries and chemical manufacturers make it reasonable for EPA to propose the 1 mile criterion for additional prevention measures such as STAA. EPA is proposing to define facility location based on distance to the facility fenceline and that ''1 mile'' be interpreted to mean ''1 mile to the nearest fenceline”.

EPA is proposing to reinstate provisions to report whether the current PHA addresses STAA, whether any IST / ISD were implemented, and, if so, to identify the measure and technology category. EPA has included an outline of the potential information that would be required in the STAA documentation in its Technical Background Document for the amendments rule.

Hydrogen Fluoride (HF)

HF is an extremely toxic chemical used for alkylation at 27 percent of facilities in NAICS 324 (45 of 163). HF has been the subject of recent catastrophic near-miss investigations by CSB where HF was nearly released when there were explosions, fires, and other releases that could have triggered HF releases. EPA is proposing that all HF alkylation processes at petroleum refineries (NAICS 324) conduct an STAA review for the use of safer alternatives compared to HF alkylation as part of their PHA.

There are recognized potentially safer alternatives available for HF alkylation that have been successfully implemented by refineries, such as sulfuric acid alkylation, ionic liquid alkylation, or solid acid catalyst alkylation. EPA contends that the practicability of these potentially safer alternatives is situation-specific and that owners and operators are usually in the best position to make these determinations. Phasing out HF or switching to an inherently safer alternative may require construction of a new alkylation unit.


EPA is proposing to add several definitions that relate to STAA. EPA is adding these definitions to describe risk reduction strategies that the owner or operator can use when considering safer technology and alternatives and to address their practicability.

Active measures: Risk management measures or engineering controls that rely on mechanical, or other energy input to detect and respond to process deviations. Examples of active measures include alarms, safety instrumented systems, and detection hardware (e.g., hydrocarbon sensors).

Inherently safer technology or design: Risk management measures that minimize the use of regulated substances, substitute less hazardous substances, moderate the use of regulated substances, or simplify covered processes in order to make accidental releases less likely, or the impacts of such releases less severe.

Passive measures: Risk management measures that use design features that reduce either the frequency or consequences of the hazard without human, mechanical, or other energy input. Examples of passive measures include pressure vessel designs, dikes, berms and blast walls.

Procedural measures: Risk management measures such as policies, operating procedures, training, administrative controls, and emergency response actions to prevent or minimize incidents. Examples of procedural measures include administrative limits on process vessel fill levels and procedural steps taken to avoid releases.

Practicability: The capability of being successfully accomplished within a reasonable time, accounting for environmental, legal, social, technological, and economic factors. Environmental factors would include consideration of potential transferred risks for new risk reduction measures.

EPA is soliciting comments on the proposed amendments and has posed questions regarding them.

If you would like further information, please click here.

To comment on this PT Note, click here.

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