Silica Regulatory Compliance & Standards

OSHA Compliance for Shop Workers (General Industry)

OSHA released its rule reducing the permissible exposure level (PEL) for crystalline silica for general industry and construction on June 23, 2016. In addition to the PEL, OSHA’s silica standards include requirements for exposure assessment, engineering and work practice controls, respiratory protection when required, medical surveillance when applicable, employee training, recordkeeping, and written exposure control plans.

Since a portion of the stone industry is covered under the Construction standard and others under the General Industry standard, the following documents and links are provided for quick reference:

• OSHA Fact Sheet: General Industry Standard
• OSHA/NIOSH Hazard Alert
• OSHA National Emphasis Program
• Silica Exposure Control Plan Template
• Online Training: Implementing a Silica Exposure Control Plan
• OSHA Inspection Planning Checklist

Employers should focus on maintaining an active silica safety program, including exposure assessment, engineering and work practice controls, respiratory protection when required, employee training, medical surveillance when applicable, recordkeeping, and a written exposure control plan.

Companies are encouraged to regularly assess their current silica exposure risks and safety efforts to ensure they remain compliant with applicable OSHA standards.

Official OSHA Silica Safety Webpage

OSHA Compliance for Field Workers (Construction)

As shared in the Shop Workers section above, OSHA released its rule reducing the permissible exposure level (PEL) for crystalline silica for general industry and construction on June 23, 2016. In addition to the PEL, OSHA’s silica standards include requirements for exposure assessment, engineering and work practice controls, respiratory protection when required, medical surveillance when applicable, employee training, recordkeeping, and written exposure control plans.

Since a portion of the stone industry is covered under the Construction standard and others under the General Industry standard, the following documents and links are provided for quick reference:

• OSHA Fact Sheet: Construction Standard
• OSHA Sample Table 1 of Construction Activities and Control Methods
• OSHA/NIOSH Hazard Alert
• OSHA National Emphasis Program
• CPWR's Create-A-Plan Tool
• OSHA Inspection Planning Checklist

Employers should maintain a comprehensive silica safety program that includes exposure assessment, engineering and work practice controls, respiratory protection when required, employee training, medical surveillance when applicable, recordkeeping, and a written exposure control plan.

Companies are encouraged to regularly evaluate their silica exposure risks and review their safety programs to help ensure ongoing compliance with applicable OSHA standards.

Official OSHA Silica Safety Webpage

MSHA Compliance for Quarry Workers

In 2024, MSHA issued a final rule titled “Lowering Miners’ Exposure to Respirable Crystalline Silica and Improving Respiratory Protection.” The final rule lowered the permissible exposure limit (PEL) for respirable crystalline silica to 50 µg/m³ for a full-shift exposure, calculated as an 8-hour time-weighted average. The rule also established an action level of 25 µg/m³ and included requirements related to exposure monitoring, corrective actions, respiratory protection, medical surveillance, and miner training.

Enforcement of MSHA’s 2024 silica rule is currently stayed pending judicial review; read more on MSHA's website. MSHA has stated that, while the stay is in place, mine operators must continue to comply with the applicable standards that existed prior to the 2024 rule. Quarriers and producers are encouraged to regularly review MSHA guidance and consult qualified safety professionals when evaluating their silica safety programs.

The following documents and links are provided for quick reference:

• MSHA Silica Final Rule Resources

• April 2024: Department of Labor Final Rule Announcement

Quarriers and producers should focus on maintaining an active silica safety program, including exposure monitoring, dust controls, respiratory protection when required, miner training, medical surveillance when applicable, recordkeeping, and review of applicable MSHA requirements.

Companies are encouraged to regularly assess their current silica exposure risks and safety efforts to ensure they remain compliant with applicable MSHA standards.

Official MSHA Silica Safety Webpage

Cal/OSHA Compliance for California Shop & Field Workers

At a minimum, state plans must be “at least effective” as federal OSHA, and can be more stringent. California’s approach adds specific prohibitions and required practices for high- exposure trigger tasks including requiring wet methods and the use of respirators. 

The following documents and links are provided for quick reference:

• Cal/OSHA RCS Standards and Resources (Shop & Field Workers)
• California Title 8, Section 5204 (Shop Workers Only)
• Cal/OSHA Silica Hazards in General Industry (Shop Workers Only)
• California Title 8, Section 1532.3 (Field Workers Only)

Since these standards and resources are rapidly evolving, we encourage you to visit the News & Updates section of this website for the latest headlines.

Official Cal/OSHA Website