MSHA silica rule: compliance deadlines stayed
The U.S. Mine Safety and Health Administration finalized new silica protections in 2024, but the compliance deadlines remain stayed. April and August 2026 federal notices confirm continued application of existing mine standards and paused enforcement of the new requirements.
The original coal and metal/nonmetal compliance deadlines are stayed. No replacement date is established in the checked sources; the court docket needs confirmation before operational reliance.
- Legal status
- Final rule; compliance deadlines stayed; conforming amendments indefinitely delayed
- Source check
- Sep 17, 2026
- Topic
- Respirable crystalline silica
- Technical review
- Jiaxi · 2026-09-23
What changed
Previous requirement
Existing mine silica and respiratory-protection standards; MNM sections 56.5001/5005 and 57.5001/5005 remain enforced during stay.
New requirement or current position
Finalized part 60 sets 50 microgram/m3 PEL, 25 microgram/m3 action level, monitoring, controls, surveillance and updated respiratory protection, but stayed deadlines must not be shown as currently due.
Who it affects
- Mining
- Aggregates
- Metal/nonmetal mines
- Coal mines
Dates and milestones
Commencement and compliance dates can differ. Read the conditions beside each date, including any stay or local adoption requirement.
- Announcement or publication
- Apr 18, 2024
- Recorded effective date
- Jun 17, 2024
Coal mine operators
Original deadline; STAYED, not a current due date.
Metal and nonmetal mine operators
Original deadline; STAYED, not a current due date.
Replacement compliance date
Not established in checked sources.
Selected exposure values
These values need the scope, limit type and averaging period shown below. A proposed or advisory value is not a binding limit.
Respirable crystalline silica
50 µg/m³| Averaging period | Full shift, 8-hour TWA |
|---|---|
| Limit type | Finalized PEL; stayed compliance |
| Scope | All miners under 2024 rule |
Respirable crystalline silica
25 µg/m³| Averaging period | Full shift, 8-hour TWA |
|---|---|
| Limit type | Finalized action level; stayed compliance |
| Scope | All miners under 2024 rule |
What this could mean for your IH program
Advisory interpretation: Keep old and finalized limit sets distinct. Do not generate overdue alerts from stayed deadlines. Continue to assess applicable existing mine standards.
Confirm applicability with a qualified practitioner before changing your program.
Questions and qualifications
- Federal notices and the August 2026 agency agenda corroborate the stay. The court docket has not been independently verified; confirm the current court and Federal Register position before operational reliance.
Source evidence
- Respirable Crystalline Silica
MSHA · Final Rule bullets
2024 rule specifies a 50 microgram/m3 PEL and 25 microgram/m3 action level as full-shift 8-hour TWAs, monitoring, medical surveillance and ASTM F3387-19 respiratory protection.
- Silica: delay of effective date of conforming amendments
MSHA / Federal Register · 91 FR 17143-17144; Dates; Background; Indefinite Delay
April 11, 2025 Eighth Circuit stay covers compliance deadlines. April 6, 2026 notice indefinitely delays conforming amendments; existing 56.5001, 56.5005, 57.5001 and 57.5005 remain enforced.
- 2026 Unified Agenda
Federal Register / MSHA · Printed p.52892, entry 102, RIN 1219-AC22; PDF p.101
August 14, 2026 agenda still describes silica enforcement as paused and plans revisions to monitoring, compliance, respirators and surveillance; agenda dates are estimates, not enacted deadlines.
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