Surface aggregates quarrying (NAICS 2123) is governed by MSHA (30 CFR Part 56) for mining operations and OSHA 1910.95 for surface processing plant operations. The jurisdictional boundary between MSHA and OSHA at aggregate operations depends on whether the specific area is engaged in extraction, proc OSHA 29 CFR 1910.95 applies to aggregates & quarry operations as general industry. According to CDC/NIOSH, approximately 22 million U.S. workers are exposed to hazardous occupational noise annually.
Soundtrace delivers in-house audiometric testing and noise monitoring for aggregates & quarry operations — ANSI S3.1-compliant, automated STS detection, and licensed audiologist review.
Noise Sources and TWA Ranges: Aggregates & Quarry
| Equipment / Process | Typical Level | Typical 8-hr TWA | OSHA Status |
|---|---|---|---|
| Crushing plant (jaw crusher / cone) | 95–115 dBA | 92–105 dBA | Significantly exceeds PEL |
| Screening / classifying equipment | 90–105 dBA | 88–98 dBA | At or above PEL |
| Conveyor drives (aggregate transfer) | 88–100 dBA | 88–95 dBA | At or above PEL |
| Drilling (surface blast hole) | 100–115 dBA | 95–108 dBA | Significantly exceeds PEL |
| Heavy mobile equipment (dozer/loader cab) | 82–92 dBA | 82–90 dBA | Modern enclosed cabs monitor; older equipment higher |
| Wash plant / dewatering equipment | 88–100 dBA | 88–96 dBA | At or above PEL |
| Scale house / office | 60–72 dBA | <72 dBA | Below action level |
Industry-Specific Compliance Considerations
Surface aggregates quarrying (NAICS 2123) is governed by MSHA (30 CFR Part 56) for mining operations and OSHA 1910.95 for surface processing plant operations. The jurisdictional boundary between MSHA and OSHA at aggregate operations depends on whether the specific area is engaged in extraction, processing, or other activities. Crushing plants, screening operations, and conveyor systems are typically OSHA-regulated even at facilities where the quarrying itself is MSHA-regulated. Employers must confirm jurisdiction for each distinct work area. See: OSHA vs. MSHA hearing conservation comparison.
OSHA 1910.95 Requirements
All aggregates & quarry workers at or above the 85 dBA action level require the full six-element OSHA 1910.95 hearing conservation program. Workers above the 90 dBA PEL require documented engineering controls assessment. The most common citation patterns across aggregates & quarry match the broader manufacturing pattern: late baseline audiograms, annual audiogram schedule failures, and inadequate HPD for PEL-exceeding exposures. See: most common OSHA hearing conservation citations.
| Violation Type | Citation Frequency | Typical Penalty (2026) |
|---|---|---|
| Late or missing baseline audiograms | Very high | $2,000–$7,000 per instance |
| Annual audiogram schedule failures | High | $2,000–$7,000 per instance |
| No noise monitoring (assumed below AL) | High | $1,000–$5,000 |
| No engineering controls assessment above PEL | Moderate | $3,000–$9,000 |
Workers’ Compensation Defense
Quarry workers face high noise exposures from crushing, drilling, and screening operations throughout their careers. The dual MSHA/OSHA jurisdiction creates multi-regulatory WC records questions that benefit from complete audiometric records from all employment periods regardless of which agency regulated each period.
Occupational hearing loss claims arrive decades after exposure begins. Records held by mobile van vendors cannot be guaranteed beyond the active vendor relationship. Cloud-based retention with employer-controlled access is the only reliable long-term solution. See: workers’ compensation for occupational hearing loss.
In-house audiometric testing for aggregates & quarry operations
Soundtrace delivers OSHA-compliant audiometric testing and noise monitoring for aggregates & quarry employers — automated STS detection, 30-year cloud retention, and licensed audiologist supervision.
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