EPA RMP vs OSHA PSM: Mechanical Integrity Overlap

Short answer: For a Program 3 process, EPA's mechanical integrity rule (40 CFR 68.73) copies OSHA's PSM rule (29 CFR 1910.119(j)) almost word for word. The equipment list, written procedures, training, inspection and testing, deficiency correction and quality assurance requirements match. The differences sit elsewhere: who enforces, who is protected (workers or the public offsite), which processes are covered, and what each agency reviews. One well-kept inspection file can satisfy both rules.

This guide is for plant engineers, mechanical integrity (MI) coordinators and environmental, health and safety (EHS) managers at sites that fall under both programmes, or under only one of them. It sets the two rules side by side and shows where they diverge. It then covers the inspection evidence that holds up when either agency audits the MI element. It does not replace reading the regulations. Both are short, public and free on the eCFR. Check the current text before you change a programme, because the RMP rule has been through several rounds of rulemaking.

Where the two rules come from, and why they look alike

Direct answer: OSHA published the PSM standard in 1992 to protect workers from catastrophic releases of highly hazardous chemicals. EPA later wrote the Risk Management Program rule under the Clean Air Act to protect the public and the environment beyond the fence line. For Program 3 processes, EPA deliberately reused OSHA's prevention-programme language.

EPA's guidance on the Program 3 prevention programme (Chapter 7 of its RMP guidance) says the Program 3 prevention programme "includes the requirements of the OSHA PSM standard". It also says EPA used OSHA's language verbatim wherever it could. EPA changed terms only where its legal authority differed from OSHA's. OSHA regulates an "employer" to protect employees. EPA regulates an "owner or operator" to protect public health and the environment. EPA also removed references to workplace "safety and health" and changed some dates.

EPA's cross-reference table lists twelve Program 3 elements, each matched to a PSM paragraph. Mechanical integrity at 40 CFR 68.73 maps to 1910.119(j). Two PSM elements have no RMP counterpart in subpart D. Emergency response is handled elsewhere in Part 68, and OSHA's trade-secrets provision is outside EPA's authority. For mechanical integrity, the practical result is simple. If your MI programme already satisfies OSHA (j) for a process that is also an RMP Program 3 process, it is built to the same requirement text EPA will read.

Clause by clause: 40 CFR 68.73 compared with 1910.119(j)

Direct answer: The six building blocks are the same: the equipment the programme covers, written procedures, training for maintenance staff, inspection and testing, correction of equipment deficiencies, and quality assurance. Read the two side by side and the obligations line up paragraph by paragraph.

EPA's Program 3 guidance gives a short MI chart in the same shape. It names API 510 (pressure vessels) and API Standard 653 (aboveground tanks) as further sources for mechanical integrity, alongside CCPS guidance on equipment reliability and process safety documentation. That chapter is an older guidance document. The point it makes still holds, because the 68.73 text has not drifted away from (j). Both agencies point to the same industry codes as good engineering practice for fixed equipment.

Where the programmes really differ

Direct answer: The MI text matches, but the programmes around it do not. They differ in who is protected, who enforces, how a process becomes covered, which program level applies, and what gets reported to the government. Those differences decide which agency can look at a given tank or pipe, and what question it asks about the inspection record.

Protected population and the "offsite" lens

OSHA's question is whether a failure could harm employees. EPA's question is whether a release could harm the public or the environment offsite. EPA's guidance gives an example from hazard analysis. Venting toxic vapour to outdoor air may protect workers but endanger the community. A PHA done only for PSM has to consider offsite impacts before it satisfies Part 68. For mechanical integrity, the same lens can change priorities. A tank whose failure would mainly affect a neighbouring community may deserve closer inspection attention under RMP than its worker-exposure ranking alone would suggest.

Coverage triggers

PSM coverage follows 1910.119(a) and the threshold quantities in its Appendix A, plus flammable liquids and gases above the standard's threshold, with listed exemptions. RMP coverage follows EPA's own list of regulated substances and thresholds in 40 CFR 68.130. The two lists overlap but are not the same. A process can therefore be RMP-covered and not PSM-covered, or the reverse. EPA's guidance uses a toluene diisocyanate (TDI) tank as an example. The tank was covered under RMP but not PSM, and would be Program 2 if considered alone. Because it sat close to chlorine equipment covered by PSM and Program 3, EPA explained that it is part of the same process if a single release event could involve both. In that case both substances, and their vessels and equipment, are subject to PSM and Program 3. The lesson for MI coordinators: the boundary of the "process" drives which equipment belongs on the MI equipment list. That boundary is not always the boundary your PSM programme drew.

Program levels

RMP assigns each covered process to Program 1, 2 or 3 under 40 CFR 68.10. A process goes to Program 3 when it does not qualify for Program 1 and either is subject to OSHA PSM or falls in one of the listed NAICS codes (for example 32411, petroleum refineries, along with listed pulp, petrochemical and chemical manufacturing codes). Program 2 processes have a lighter maintenance section (68.56). It still requires procedures, training, and inspections and tests that follow recognized good engineering practice, at a frequency that reflects manufacturers' recommendations, industry standards and operating experience. Program 2 does not carry the same documentation list and deficiency text as 68.73. Program 1 processes have no prevention programme MI element at all.

Enforcement and implementing agencies

OSHA enforces PSM directly or through approved State Plans. EPA enforces RMP through its regions or through delegated state and local implementing agencies. California, for example, runs its accidental release prevention programme (CalARP) through local agencies, and some states have programmes of their own. A plant can face an OSHA inspector under the PSM national emphasis programme one year and an EPA or state RMP inspector the next. Both will ask for the MI file.

Reporting

PSM records stay on site for OSHA review. RMP requires a risk management plan submitted to EPA and updated on the rule's schedule. The plan summarises the prevention programme, including the date of the most recent review or revision of maintenance procedures and inspection activity. The inspection data itself stays on site. The plan, however, makes claims about the programme that an inspector can test against your records.

The RMP rulemaking timeline to watch

Direct answer: The MI section has been stable. The rest of the RMP rule has not. EPA amended RMP in 2017 and 2019, and in 2024 it issued the Safer Communities by Chemical Accident Prevention (SCCAP) rule. In February 2026 EPA proposed a "Common Sense Approach to Chemical Accident Prevention" rule that would roll back much of SCCAP and realign RMP more closely with OSHA PSM.

EPA's own rulemaking page shows the February 24, 2026 proposal, a public hearing on March 10, 2026, and a comment period that closed on May 11, 2026. Law-firm summaries of the proposal describe rollbacks of safer-technology analysis, third-party audit, employee participation, information-sharing and some emergency-response provisions added in 2024. None of those summaries describes a rewrite of the 68.73 MI text. When this guide was written, we could not confirm that a final rule had been published. Before you rely on any element outside mechanical integrity, check the current eCFR text of Part 68 and EPA's RMP rulemaking page. Ask your counsel or EHS lead which version your facility is following.

For inspection planning this matters less than it might seem. The equipment list, RAGAGEP basis, documentation elements and deficiency language in 68.73 have stayed aligned with (j) through each round. A sound MI file built to the PSM text stays sound under RMP.

One inspection record that satisfies both agencies

Direct answer: Build every inspection and test record so that it meets the five documentation elements common to both rules. Link it to the code or RAGAGEP that sets the method and interval, and record what happened to any deficiency. That single record format serves OSHA, EPA and any state implementing agency.

A record that works for both agencies usually contains:

• The five required elements: date; name of the person who performed the inspection or test; equipment serial number or tag; description of the inspection or test; results.
• The RAGAGEP reference: the code and edition the work followed. For example, API 510 for a vessel, API 570 for a piping circuit, API 653 for a field-erected tank, and the manufacturer's recommendations for pumps and instruments.
• Method detail that makes the result reproducible: for ultrasonic thickness, the instrument, probe, calibration block and condition monitoring location (CML) identifiers. For visual examination, the scope and what was accessible. For relief devices, the test bench result and as-found and as-left condition.
• Comparison to the acceptance basis: the minimum required thickness or other limit from the engineering basis, so a reader can see whether the result is inside or outside acceptable limits.
• Deficiency disposition: if a result is outside limits, the date of the finding, who was told, and whether the equipment was repaired or taken out of service. If it stayed in service, the interim measures that assured safe operation and the work order that closed it.
• Signature of the qualified person and, for API-code equipment, evidence that the owner's authorized inspector reviewed the result and set or confirmed the next interval.

A worked example, described qualitatively: a refinery has a storage tank holding a flammable mixture inside a Program 3 process. The tank's external inspection under API 653 is due. The inspection contractor takes shell UT readings at the established CMLs and examines the foundation and appurtenances. It reports one course where the reading trend suggests a faster corrosion rate than predicted. The authorized inspector reviews the data, recalculates remaining life and shortens the next interval. The owner raises a work order to recoat the affected area. One record, with that full chain of evidence, answers OSHA's (j)(4) and (j)(5) questions. It answers EPA's 68.73(d) and (e) questions too. Nobody has to keep a second copy "for EPA".

NDE methods that produce MI evidence, and their limits

Direct answer: Neither rule names an NDE method. RAGAGEP does. In practice, MI evidence for vessels, piping and tanks comes from ultrasonic thickness testing, corrosion mapping, external visual examination, and surface crack methods at welds. Profile radiography and screening tools such as guided wave or MFL tank-floor scanning are added where access or coverage demands. Each method answers a specific question and misses others.

For deeper method selection by damage mechanism, see our guide on NDE method selection by damage mechanism. For the thickness-data step that feeds intervals, see long-term and short-term corrosion rate calculation.

Common mistakes at dual-covered sites

Direct answer: The usual errors are boundary errors and record errors, not technical errors. Examples are equipment missing from the MI list because a process boundary was drawn for PSM only, and records without the required elements. Others are deficiencies left open without documented interim measures, and RMP plan statements that do not match the on-site file.

• Drawing the MI equipment list from PSM coverage only. RMP-only processes and RMP-only substances still need an MI programme at Program 3, and a maintenance programme at Program 2.
• Treating "PSM compliant" as automatically "RMP compliant". The MI text matches, but the process boundary, the offsite-consequence lens and the plan reporting differ.
• Leaving out the RAGAGEP basis. An interval with no reference to the code or manufacturer guidance behind it is hard to defend in front of either agency.
• Losing the deficiency trail. Both rules require deficiencies outside acceptable limits to be corrected before further use, or in a safe and timely manner with measures to assure safe operation. The record has to show which route was taken.
• Contractor reports that stop at raw data. If an NDE report gives readings with no CML identification and no comparison to minimum thickness, the owner's inspector has to rebuild that context later. Auditors notice the gap.
• Assuming the RMP text is static. Elements outside MI have changed several times. Confirm which provisions are in force before an audit.

Canada and other jurisdictions

Direct answer: Canada has no single equivalent to the PSM and RMP pairing. Federal environmental emergency planning for listed substances falls under the Environmental Emergency Regulations made under the Canadian Environmental Protection Act. Equipment integrity for pressure vessels and piping comes from provincial pressure-equipment law and the regulators that run it, such as ABSA in Alberta and TSSA in Ontario.

A Canadian site's MI evidence usually rests on the provincial integrity-management requirements and the codes they adopt. API 510, 570 and 653 are often used as the in-service standards within those programmes, so the same inspection record discipline applies. Confirm the current federal and provincial requirements for your site before you treat a US-style programme as compliant. At US sites in State Plan states or with delegated RMP programmes, check whether the state adds requirements beyond the federal text.

How Atlantis supports this

Atlantis NDT performs the inspection work that fills the MI file. That includes UT thickness and CML surveys, corrosion mapping and phased array, external visual examination, MT and PT at welds, tank-floor MFL scanning with UT prove-up, and guided-wave screening. The work is done by ASNT-certified technicians under ASNT Level III oversight. Our reports carry the five documentation elements both rules require, identify CMLs, and compare results with the acceptance basis the owner supplies. That lets the owner's API-certified authorized inspector review the data, set intervals and decide deficiency dispositions. Atlantis is not the authorized inspector, and programme ownership stays with the owner or operator. See inspection services, piping circuit CML inspection, pressure vessel inspection and aboveground storage tank inspection. Request a scope review and quote; we respond within 24 hours.

For the PSM side of the same file, our page on how 1910.119(j) reaches NDT records goes paragraph by paragraph. Our chemical plant MI programme article covers threshold quantities and audits.

Frequently asked questions

What is the difference between EPA RMP and OSHA PSM mechanical integrity?

For Program 3 processes the requirement text is essentially the same. 40 CFR 68.73 mirrors 1910.119(j) in equipment coverage, procedures, training, inspection and testing, deficiencies and quality assurance. The difference is the regulator (EPA or OSHA), the protected population (the public and environment offsite, or workers), how processes are covered, and RMP's plan reporting.

Does OSHA PSM compliance satisfy RMP Program 3 mechanical integrity?

For a process covered by both, an MI programme that meets (j) generally meets 68.73, because EPA used OSHA's language. But confirm that the process boundary and equipment list cover everything Part 68 covers, including RMP-only substances, and that offsite consequences are considered.

What does 40 CFR 68.73 require?

An MI programme for pressure vessels and storage tanks, piping systems, relief and vent systems, emergency shutdown systems, controls and pumps. It requires written procedures, training for maintenance employees, and inspections and tests that follow good engineering practice at an appropriate frequency. It also requires documented records, correction of deficiencies, and quality assurance for new and replacement equipment and materials.

Can a process be covered by RMP but not PSM?

Yes. The two programmes use different chemical lists and thresholds. EPA's guidance gives the example of a toluene diisocyanate tank covered by RMP but not PSM. Such a process still needs RMP prevention-programme elements at its program level.

What are RMP Program 3 mechanical integrity requirements for Program 2 processes?

Program 2 uses a separate maintenance section, 40 CFR 68.56. It requires maintenance procedures, training, and inspections and tests that follow recognized good engineering practice at a frequency based on manufacturers' recommendations, industry standards and operating experience. It is lighter than the Program 3 MI element.

Which codes count as good engineering practice for RMP inspection?

Neither rule lists codes. EPA's Program 3 guidance names API 510 and API Standard 653 as sources, and API 570 is widely used for piping. The owner selects and documents the RAGAGEP.

Who enforces RMP mechanical integrity?

EPA regions, or state and local agencies that have accepted delegation of the RMP programme. OSHA or an approved State Plan enforces PSM at the same site.

Is the RMP rule changing in 2026?

EPA proposed revisions in February 2026, and the comment period closed in May 2026. Check EPA's RMP rulemaking page and the current eCFR text for the final status. Published summaries do not describe changes to the 68.73 MI text.

What must an MI inspection record contain under both rules?

The date, the name of the person who performed it, the equipment serial number or identifier, a description of the inspection or test, and the results. Good practice adds the RAGAGEP reference, the acceptance basis and any deficiency disposition.

Does an NDT contractor become responsible for RMP compliance?

No. The owner or operator holds the RMP obligation. Contractors perform inspections and tests and supply records. Programme decisions on intervals and deficiencies stay with the owner and, for API-code equipment, the owner's authorized inspector.

Planning an MI cycle at a dual-covered site? Send us your equipment list for an inspection quote, or ask about report formats that meet both rules.