Authority and source notes

Subpart Z was issued primarily under 29 U.S.C. 655(b), but the exposure limits listed in 1910.1000 Tables Z-1, Z-2, and Z-3 were issued under different authority (including 29 U.S.C. 655(a) and 5 U.S.C. 553) and are treated separately. The Subpart Z authority text explains that "All of subpart Z [was] issued under 29 U.S.C. 655(b), except those substances that have exposure limits listed in Tables Z-1, Z-2, and Z-3 of 1910.1000," and that the latter tables were also issued under 5 U.S.C. 553. See 29 CFR part 1910 Subpart Z.

The exposure limits in Tables Z-1, Z-2, and Z-3 were issued under authorities that include 5 U.S.C. 553 and 29 U.S.C. 655(a), and employers must apply those limits as regulatory requirements in the same way they apply other OSHA limits. The Subpart Z authority note clarifies that the tables in 1910.1000 were issued under 5 U.S.C. 553 (and, where applicable, 29 U.S.C. 655(a)), so the values in Tables Z-1, Z-2, and Z-3 are enforceable regulatory exposure limits that employers must follow; see 29 CFR part 1910 for context.

No — remediation activities involving asbestos-containing building materials are generally covered by the construction asbestos standard, not the general industry standard. OSHA's interpretation explains that even if a remediation company does not fit the typical construction profile, described remediation activities involving ACBM would be covered by the construction asbestos standard [29 CFR 1926.1101], not the general industry standard 29 CFR 1910.1001; see OSHA's letter on asbestos remediation protocols at https://www.osha.gov/laws-regs/standardinterpretations/2024-11-14 for details and practical guidance.

Employers must follow a specific sequence of protective actions before temporarily re-energizing equipment for testing or positioning, and they must maintain effective employee protection during the energized period. OSHA's interpretation of 29 CFR 1910.147(f)(1) requires that employers (1) clear the machine of tools and materials, (2) remove employees from hazardous areas around the machine, (3) remove lockout/tagout devices as specified, (4) energize the machine and provide effective protections while testing or positioning, and (5) de-energize and reapply lockout/tagout devices if further servicing is required; see OSHA's letter on the minor servicing exception at https://www.osha.gov/laws-regs/standardinterpretations/2024-10-21 for the full explanation.

No — handrails are not treated as obstructions or vertical barriers when measuring standard stair width between vertical barriers. OSHA's interpretation clarifies that 29 CFR 1910.25(c)(4) requires a minimum stair width measured between vertical barriers and that handrails are not considered vertical barriers for that measurement; see OSHA's stair width guidance at https://www.osha.gov/laws-regs/standardinterpretations/2024-10-17 for supporting detail.

Yes — storing pre-charged units that together contain a Category 1 flammable gas above the threshold quantity in one location meets the PSM "process" definition and is covered by 29 CFR 1910.119. OSHA's June 6, 2024 interpretation explains that storage and on-site movement of pre-charged appliances containing a Category 1 flammable gas in aggregate quantities at or above 10,000 pounds constitute a PSM-covered process; see https://www.osha.gov/laws-regs/standardinterpretations/2024-06-06 and 29 CFR part 1910 for background.

Yes — employers must provide and require protective helmets for employees who are working where there is a potential for head injury from falling objects during crane or hoisting operations. OSHA's letter states that 29 CFR 1910.135(a)(1) requires helmets when the risk exists, and 1910.135(b)(1) requires helmets to meet ANSI Z89.1 consensus standards (acceptable editions are incorporated by reference); see OSHA's head protection guidance for crane operations at https://www.osha.gov/laws-regs/standardinterpretations/2024-06-06-2 for more detail.

No — simply stepping onto a low-slope roof from a portable ladder and walking 25 feet from the edge does not automatically require fall protection, but fall protection may be required depending on whether the work to be performed is "infrequent and temporary" or if work will occur within distances that trigger the standard. OSHA's interpretation explains that 29 CFR 1910.28(b)(13)(iii) governs fall protection for low-slope roofs and that employers must provide protection when work is performed less than 6 feet from the roof edge or when work is not merely infrequent and temporary; see https://www.osha.gov/laws-regs/standardinterpretations/2024-06-06-1 for context and examples.

Mobile ladder stands and platforms must meet specific dimension and guardrail rules: steps must be uniformly spaced with a rise not over 10 inches and a tread at least 7 inches deep; the step width must be at least 16 inches; and platforms above certain heights require handrails, midrails, guardrails, or toeboards as specified. OSHA's interpretation cites the mobile ladder stand rules in 29 CFR 1910.23 and summarizes that steps must have a minimum 16-inch width, rises ≤10 inches, tread depth ≥7 inches, handrails for platform heights of 4–10 feet, and guardrails/toeboards for platforms above 10 feet; see https://www.osha.gov/laws-regs/standardinterpretations/2024-06-06-0 for details.

No — OSHA announced an immediate enforcement stay of the COVID-19 Healthcare ETS recordkeeping and reporting requirements and will not cite employers for those specific provisions until further notice. OSHA's memorandum states it will not enforce the requirements to maintain COVID-19 logs under 29 CFR 1910.502(q) or to report COVID-19 fatalities and hospitalizations under 1910.502(r), and it refers enforcement back to the conventional recordkeeping rules (see https://www.osha.gov/laws-regs/standardinterpretations/2025-02-05).

Yes — where civilian employees are covered by OSHA (for example, contractor employees working at DoD facilities on non-unique military equipment), OSHA's Respiratory Protection Standard defines an oxygen-deficient atmosphere as below 19.5% oxygen and requires treating such atmospheres as IDLH unless narrow, altitude-based exceptions apply. OSHA's interpretation explains the scope for DoD facilities and confirms that civilian employees covered by OSHA must follow [29 CFR 1910.134] and the related oxygen-deficiency requirements; see https://www.osha.gov/laws-regs/standardinterpretations/2024-07-16 for full context.

Yes — C-type light truck tires that are similar to LT tires can fall within the scope of 29 CFR 1910.177 for rim wheel servicing, and noncompliance with portions of 1910.177 for pickup trucks and vans using C-type tires may be treated as de minimis in certain fact-specific situations. OSHA's interpretation finds that C-type tires may be covered by 1910.177 depending on installation and servicing methods and notes the de minimis consideration; see https://www.osha.gov/laws-regs/standardinterpretations/2024-08-01 and 29 CFR part 1910 for background.

Top rails on guardrail systems must withstand at least 200 pounds of force applied downward or outward within 2 inches of the top edge without failure. OSHA's mobile ladder stand interpretation cites the guardrail strength requirement found in 29 CFR 1910.29(b)(3) and applies it to mobile ladder platforms where guardrails are required; see https://www.osha.gov/laws-regs/standardinterpretations/2024-06-06-0 for the practical application.

The Bloodborne Pathogens standard, 29 CFR 1910.1030, was issued under Public Law 106-430 in addition to other authorities. The Subpart Z authority note explicitly lists that 1910.1030 was issued under Public Law 106-430; see 29 CFR part 1910 for citation information.

Section 1910.1201 was issued under 49 U.S.C. 1801–1819 and also under 5 U.S.C. 553, indicating it was promulgated under both transportation-related statutory authority and the Administrative Procedure Act procedures. The Subpart Z authority notes state that 29 CFR 1910.1201 was issued under those authorities; see 29 CFR part 1910 for the authority summary.