NESHAP — 40 CFR Part 61

Part 61 covers specific pollutants — principally asbestos, benzene, beryllium, mercury, radionuclides, and vinyl chloride — that EPA designated as hazardous under the original Section 112 framework.

After the 1990 Clean Air Act Amendments, Congress restructured the HAP program and directed EPA to develop source-category-specific standards based on Maximum Achievable Control Technology (MACT). These new standards are codified in 40 CFR Part 63. Part 61 standards remain in effect for the specific pollutants they cover, but most new source-category regulations are now issued under Part 63.

Part 61 subparts relevant to industrial LDAR

The most industrially relevant Part 61 LDAR subparts:

• Subpart J — Benzene equipment leaks. Applies to facilities with equipment in benzene service, with leak detection and repair requirements similar in structure to NSPS equipment leak rules.
• Subpart V — Fugitive emission sources (equipment leaks provisions referenced by other NESHAP subparts).

How Part 61 relates to Part 63

For most post-1990 source category standards, Part 63 (MACT) supersedes or complements Part 61 requirements. Facilities subject to Part 61 Subpart J for benzene may also be subject to a Part 63 NESHAP for the broader source category — for example, a refinery is subject to the Refinery NESHAP at Part 63 Subpart CC, which covers benzene-containing streams.

Compliance is typically integrated across both Parts 61 and 63 where applicable, with the more stringent requirement controlling.

Enforcement

Part 61 is enforceable under Clean Air Act Section 113. Civil penalties are adjusted annually for inflation under 40 CFR 19.4.

The role of P&IDs

Part 61 equipment leak provisions — like all LDAR programs — depend on a complete, drawing-traceable component inventory. The governing P&ID is the source record for identifying which equipment is in hazardous service and therefore subject to Part 61 requirements.