Occupational safety International framework and country guides
Which rules apply to major-hazard chemical sites in the United States?
Part of: Occupational safety and health in United States: law, authorities and employer duties
Short answer
Two federal rules apply together: OSHA Process Safety Management (29 CFR 1910.119) protects workers at processes above threshold quantities of listed or flammable chemicals, and the EPA Risk Management Program (40 CFR Part 68) protects the public. The CSB investigates.
Major-hazard chemical sites in the United States are covered by two federal rules that work side by side: OSHA's Process Safety Management standard (PSM, 29 CFR 1910.119), which protects workers, and the Environmental Protection Agency's Risk Management Program (RMP, 40 CFR Part 68), which protects the community and the environment. There is no single Seveso-type law; the independent Chemical Safety Board (CSB) investigates serious chemical accidents.
Short answer
- OSHA PSM (1910.119): applies to processes with a listed highly hazardous chemical at or above its threshold quantity (Appendix A), or 10,000 pounds (4,535.9 kg) or more in one location of a Category 1 flammable gas or a flammable liquid with a flash point below 100 °F (37.8 °C).
- PSM exclusions: retail facilities, oil and gas well drilling or servicing, and normally unoccupied remote facilities; fuels used only as workplace fuel and certain atmospheric storage of flammable liquids are also carved out.
- PSM fixed intervals: process hazard analysis revalidated at least every 5 years; compliance audit at least every 3 years; incident investigation started within 48 hours; refresher training at least every 3 years.
- EPA RMP (Clean Air Act Section 112(r)): facilities with more than a threshold quantity of a regulated substance in a process submit a risk management plan, revised and resubmitted every 5 years.
- Current rulemaking: EPA amended the RMP rule in 2024 (the Safer Communities by Chemical Accident Prevention rule) and on 24 February 2026 published a further proposal, the Common Sense Approach to Chemical Accident Prevention proposed rule (comments closed 11 May 2026); check the current text before relying on any 2024 provision.
- State Plans enforce PSM in their states and may add their own requirements; check the state rules.
OSHA Process Safety Management: the 14 elements
PSM is a performance-based management standard. Covered employers must implement:
| Element | Paragraph |
|---|---|
| Employee participation | (c) |
| Process safety information | (d) |
| Process hazard analysis (revalidate at least every 5 years) | (e) |
| Operating procedures | (f) |
| Training (refresher at least every 3 years) | (g) |
| Contractors | (h) |
| Pre-startup safety review | (i) |
| Mechanical integrity | (j) |
| Hot work permit | (k) |
| Management of change | (l) |
| Incident investigation (start within 48 hours) | (m) |
| Emergency planning and response | (n) |
| Compliance audits (at least every 3 years) | (o) |
| Trade secrets | (p) |
EPA Risk Management Program
The RMP rule implements Clean Air Act Section 112(r). A covered facility must carry out a hazard assessment (worst-case and alternative release scenarios and a five-year accident history), run a prevention programme (safety information, maintenance, monitoring, training) and an emergency response programme, and submit its risk management plan to EPA, revising and resubmitting it every five years. Many facilities fall under both PSM and RMP, and the RMP prevention programme covers many of the same topics as PSM (safety information, maintenance, monitoring, training), so a single integrated management system can serve both.
EPA's regulated-substance list and thresholds differ from OSHA's Appendix A, so a site can be covered by one rule and not the other. Check both lists for every substance and process.
Example: A propane distribution terminal holds 60,000 pounds of propane in one process. It exceeds the 10,000-pound flammable threshold for PSM, unless an exclusion applies (for example, retail facilities are excluded from PSM). Propane is also on EPA's list, with a 10,000-pound threshold (40 CFR 68.130), but EPA excludes a flammable substance used as a fuel or held for sale as a fuel at a retail facility (40 CFR 68.126). If no exclusion applies, the terminal must also submit a risk management plan and resubmit it every five years.
The CSB and lessons from investigations
The Chemical Safety and Hazard Investigation Board has operated since 1998. It investigates accidental chemical releases that cause deaths, serious injuries or substantial property damage, and makes recommendations to companies, industry bodies, standards developers and regulators. It does not issue fines or citations and has no power to make regulations. Its reports are a free source of lessons for process safety training.
Compared with the EU and Türkiye
The EU Seveso III Directive (2012/18/EU) uses lower and upper tiers based on quantities of dangerous substances, with a major-accident prevention policy for all and a safety report for upper-tier sites, plus public information and land-use planning. Türkiye transposes it through the Regulation on the Prevention and Mitigation of Major Industrial Accidents (Büyük Endüstriyel Kazaların Önlenmesi ve Etkilerinin Azaltılması Hakkında Yönetmelik), known as BEKRA. The US approach splits worker protection (OSHA) and public protection (EPA) between two agencies and two rules.
Common mistakes
- Checking only one list. PSM and RMP thresholds and substance lists differ.
- Missing the 5-year PHA revalidation or the 3-yearly audit. Both are fixed by the standard.
- Relying on the 2024 RMP amendments without checking. EPA has proposed further changes in 2026.
Related on excodex
- Occupational safety and health in United States: law, authorities and employer duties
- Process safety management systems: OSHA PSM's 14 elements and CCPS
- Which facilities are covered by OSHA PSM?
- OSHA PSM vs EPA Risk Management Program
- Seveso III: major-accident prevention, tiers and duties
Standards and further reading
- 29 CFR 1910.119 Process safety management of highly hazardous chemicals: https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.119
- 40 CFR Part 68, EPA Risk Management Program: https://www.epa.gov/rmp
- EPA RMP rule overview: https://www.epa.gov/rmp/risk-management-plan-rmp-rule-overview
- 40 CFR 68.126 (fuel exclusion) and 68.130 (list of regulated substances): https://www.ecfr.gov/current/title-40/chapter-I/subchapter-C/part-68/subpart-F/section-68.130
- US Chemical Safety and Hazard Investigation Board: https://www.csb.gov/about-the-csb/
- Directive 2012/18/EU (Seveso III)
This article is general occupational safety and health information prepared by the excodex editorial team. It does not replace the applicable legislation, standards, manufacturers' instructions or the assessment of a competent OSH professional or occupational physician.
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Part of: Occupational safety and health in United States: law, authorities and employer duties