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PT Notes

Incident Investigation Root Cause 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.

This PT Note describes proposed amendments to EPA's Risk Management Program regulation relating to incident investigation root cause analysis.

The proposed rule would require all facilities with Program 2 or 3 processes to conduct a root cause analysis as part of an incident investigation of a catastrophic release or an incident that could have reasonably resulted in a catastrophic release (i.e. a near-miss). This provision is intended to reduce the number of chemical accidents by requiring facilities to identify the underlying causes of an incident so that they may be addressed. EPA believes that identifying the root causes, rather than isolating and correcting solely the immediate cause of the incident, will help prevent similar incidents at other locations, and will yield the maximum benefit or lessons learned from the incident investigation.

To accomplish these objectives, EPA is proposing:

  • Changes to the definition of catastrophic release.
  • A definition of root cause.
  • Requirements for root cause analysis.
  • Clarification of the consideration of near miss incidents.
  • A specified investigation timeframe.
  • Modifications to accident history reporting.

These are described below.

Meaning of Catastrophic Release

EPA believes that incident investigation was not intended to be and should not be limited to only those incidents with offsite impacts. EPA believes that learning from accident causes identified from incident investigations involving only workers can also lead to preventing incidents with further impacts to the surrounding community and, therefore, findings and recommendations from all incidents should be addressed regardless of who is impacted.

Consequently, EPA is proposing to modify the definition of catastrophic release to be identical to the description of accidental releases required to be reported under the accident history reporting requirements. The proposed definition replaces the language in the present definition, “that presents imminent and substantial endangerment to public health and the environment”, with, “that results in deaths, injuries, or significant property damage on-site, or known offsite deaths, injuries, evacuations, sheltering in place, property damage, or environmental damage”. EPA believes this better defines the impacts for incidents requiring investigations that caused or could have caused these impacts and clarifies EPA's intent, rather than leaving it open for interpretation.

EPA believes that redefining the term catastrophic release to include the categories of accidents that require reporting under the accident history provisions clarifies, rather than expands, that definition. Nevertheless, EPA is seeking comments on the proposed revision to the catastrophic release definition, whether it expands the scope of the current definition instead of clarifying it, and whether the definition should be limited to loss of life; serious injury; significant damage; or loss of offsite property.

Root Causes

The current RMP incident investigation requirements do not explicitly require root causes to be determined and reported; rather they only require “the factors that contributed to the incident” to be addressed. EPA believes that facility owners and operators who conduct incident investigations that only identify “factors that contributed to the incident” may miss identifying the underlying, system-related reasons why an incident occurred which would be revealed in a root cause analysis. Thus, EPA is proposing to require the owner or operator of Program 2 and Program 3 processes to determine and identify the contributing factors, including immediate and contributory causes, either direct or indirect, and root causes for all incidents that resulted in, or could reasonably have resulted in, a catastrophic release. EPA is proposing to define “root cause” as “a fundamental, underlying, system-related reason why an incident occurred that identifies a correctable failure(s) in management systems”.

EPA believes that providing the following information is vital for understanding the nature of the incident and should be included in the incident investigation report:

  • Chronological order of details of the incidents.
  • Chemical identity, amount and duration of the release.
  • Impacts of the release.
  • Basic and contributory causes, either direct or indirect.

EPA believes some facility owners or operators may already include this information in incident investigation reports prepared to comply with the RMP rule. However, EPA is proposing revisions to require this information to ensure clarity and consistency among reports.

In order that lessons learned from incident investigations be applied, EPA is proposing to modify the hazard review and PHA requirements to require the owner or operator to address findings from all incident investigations required under the revised regulation. EPA is also proposing to require that for incident investigations conducted by Program 2 sources, an incident investigation team be established and consist of at least one person knowledgeable in the process involved and other persons with appropriate knowledge and experience to thoroughly investigate and analyze the incident. This requirement is already part of Program 3 incident investigation requirements, and is a necessary component for investigations that would include analysis of root causes.

EPA is seeking comments on:

  • Requiring root cause investigations for each incident which resulted in, or could reasonably have resulted in, a catastrophic release.
  • Proposed definition of root cause.
  • Whether a root cause analysis is appropriate for every RMP reportable accident and near miss.
  • Whether EPA should eliminate the root cause analysis, or revise it to limit or increase the scope or applicability of the root cause analysis requirement. If so, how should EPA revise the scope or applicability of this proposed requirement?
  • Requiring consideration of incident investigation findings in the hazard review and PHA requirements.
  • Additional requirement to require personnel with appropriate knowledge of the facility process and knowledge and experience in incident investigation techniques to participate on an incident investigation team.

Decommissioned Processes

EPA has encountered some cases where a facility chose not to conduct an incident investigation because the owner or operator elected to decommission the process involved, or because the process was destroyed in the incident. EPA believes that while an investigation would have no impact on a decommissioned or destroyed process, other similar processes or operations at the facility, or at similar facilities, could potentially benefit from its findings. Therefore, EPA is proposing revisions to clarify that incident investigations are required even if the process involving the regulated substance is destroyed or decommissioned following or as the result of an incident.

EPA is also proposing a revision, which addresses updates to the RMP, to require that prior to any de-registration of a process or stationary source that is no longer subject to the RMP rule, the owner or operator must report any accidents subject to the rule requirements and conduct required incident investigations.

EPA is seeking comments on the proposed revisions to require an owner or operator to meet applicable reporting and incident investigation requirements prior to de-registering a process.

Near Misses

The current incident investigation provisions require facilities with Program 2 and/or 3 processes to investigate incidents that could reasonably have resulted in a catastrophic release. These types of incidents are sometimes characterized as “near misses” but there is confusion about what this term means. Because it is difficult to prescribe the various types of incidents that may occur in RMP-regulated sectors that should be considered near misses, and therefore be investigated, EPA is not proposing a regulatory definition. Instead, EPA will rely on facility owners or operators to decide which incidents to investigate, based on the seriousness of the incident, the process(es) involved, and the specific conditions and circumstances involved.

The intent is not to include every minor incident or leak, but to focus on serious incidents that could have resulted in a catastrophic release, although EPA acknowledges this will require subjective judgment.

EPA expects that lessons learned from near miss incident investigations be considered when conducting a hazard review or PHA. Therefore, proposed amendments would require the hazard review and the PHA to include findings from all required incident investigations. This includes incidents that could reasonably have resulted in a catastrophic release, i.e. a near miss.

EPA is seeking comments on guidance and examples provided of a near miss in the Federal Register. Specifically, EPA is asking:

  • Is further clarification needed in this instance?
  • Should EPA consider limiting root cause analyses only for incidents that resulted in a catastrophic release?

Investigation Timeframe

EPA believes incident investigations will result in improved process safety through the dissemination of lessons learned and the implementation of recommended corrective actions, and that conducting these investigations as soon as possible after an incident may yield better quality data and information, although it may take time to collect, validate, and integrate data from a range of sources.

EPA is proposing to require that facility owners or operators complete an incident investigation report within 12 months of an incident that resulted in, or could reasonably have resulted in, a catastrophic release. For very complex incident investigations that cannot be completed within 12 months, EPA is allowing an extension of time if the implementing agency approves, in writing.

EPA is seeking comments on:

  • The appropriateness of establishing a specific timeframe for incident investigations to be completed and what that timeframe should be.
  • Whether the incident investigation should be completed prior to restart of the affected process, if the incident resulted in a process shutdown, to ensure that the causes of an incident have been addressed, or whether there are other options to ensure that unsafe conditions that led to the incident are addressed before a process is re-started.
  • Whether the different root cause analysis timeframes specified under the petroleum refinery maximum achievable control technology (MACT) and New Source Performance Standards (NSPS) regulations and proposed herein will cause any difficulties for sources covered under both rules, and if so, what approach EPA should take to resolve this issue.

Accident History Reporting

EPA believes it is important to determine and report results of root cause analysis for accidents with reportable impacts in the RMP accident history. Therefore, EPA has proposed that information on root causes analyzed as part of an incident investigation be included in the RMP accident history. Because there can be numerous potential incident root causes identified for a single incident, and in order to simplify reporting for the RMP accident history, EPA believes that the root cause information should be reported as root cause categories.

EPA will modify its on-line reporting system for RMPs (RMP*eSubmit) to incorporate an appropriate list of root cause categories for RMP facility incident investigations of RMP reportable accidents based on categories specified in the Federal Register.

Because EPA is proposing that the incident investigation be required to be completed within 12 months, root causes may not be known until 12 months after an accidental release. The current rule requires that the accident history information be submitted within six months of the release. Because EPA is proposing to add accident root cause categories, EPA is also proposing that the root cause categories be submitted in the RMP within 12 months of the release.

EPA is seeking comments on the appropriateness of requiring root cause reporting as part of the accident history requirements as well as the categories that should be considered and the timeframe within which the root cause information must be submitted.

Alternative Options

EPA considered limiting these requirements to the original universe of Program 3 processes that existed before OSHA changed its PSM retail exemption. Accidents occur at a higher frequency in these processes as compared to processes covered in Program 2. However, with the shift of many Program 2 processes into Program 3 due to OSHA's revised policy on the PSM retail facility exemption, most of the accidents at remaining Program 2 processes occur at publicly-owned water and wastewater treatment facilities that are not in Program 3 because they are not subject to OSHA PSM. State and local government employees at facilities in states under Federal OSHA authority are not covered by the OSHA PSM standard unlike state and local government employees at facilities in states with OSHA approved State Plans. These processes pose the same risk as the publicly owned water/wastewater treatment processes that are in Program 3.

EPA decided that there was little justification for limiting the proposed requirements to the changed universe of Program 3 processes after the OSHA retail exemption change; there are fewer than six RMP reportable accidents a year at remaining Program 2 processes. Although the alternative would be slightly less burdensome on the regulated community, it would also likely prevent fewer accidents than the proposed approach.

EPA is seeking comments on the alternative approach and whether there are any other alternative options that EPA should consider prior to issuing a final action.

Further details can be found at:


Comments on the proposed amendments must be submitted on or before May 13, 2016. Comments should be identified by docket EPA-HQ-OEM-2015-0725 and submitted through to the Federal eRulemaking Portal: http://www.regulations.gov.


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