When it comes to protecting workers from the harmful effects of respirable crystalline silica, both Federal OSHA and Cal/OSHA have established regulations but they are not identical. California’s Division of Occupational Safety and Health (Cal/OSHA) often takes a more stringent approach to workplace safety. If you’re a contractor, EHS manager, or property owner in California, it’s essential to understand how silica testing requirements differ between these two regulatory bodies.
What is Respirable Crystalline Silica?
Respirable crystalline silica is a fine dust created when materials like concrete, brick, stone, or artificial stone are cut, ground, or drilled. Prolonged exposure can cause severe health issues, including:
- Silicosis
- Lung cancer
- Chronic obstructive pulmonary disease (COPD)
- Kidney disease
Federal OSHA’s Respirable Silica Standard
The U.S. Occupational Safety and Health Administration (OSHA) enforces a standard for occupational exposure to respirable crystalline silica under:
Key Federal OSHA Requirements Include:
- Permissible Exposure Limit (PEL): 50 µg/m³ averaged over an 8-hour shift.
- Action Level (AL): 25 µg/m³ (triggers medical surveillance and other requirements).
- Exposure Assessment: Employers must assess employee exposure using either:
- Performance option (objective data)
- Scheduled monitoring option (personal air monitoring)
- Engineering Controls & Work Practices: Required when exposures exceed the PEL.
- Written Exposure Control Plan: Must be implemented and maintained.
- Medical Surveillance: Required if employees are exposed above the AL for 30 or more days per year.
How Cal/OSHA Silica Regulations Differ
California has adopted the federal silica rules with modifications. Cal/OSHA regulations are found in:
Key Differences Under Cal/OSHA:
- Trigger Levels and Monitoring Frequency
- Cal/OSHA typically requires more frequent exposure assessments, especially if any employee exposure is suspected to exceed the Action Level.
- They also have stricter interpretation of what constitutes “objective data” for the performance option.
- Medical Surveillance
- Under Cal/OSHA, medical surveillance must be offered at no cost to the employee and during working hours, with clear documentation and employee rights emphasized.
- Cal/OSHA enforces stronger worker privacy protections related to medical information.
- Written Control Plans
- Cal/OSHA expects greater detail in written Exposure Control Plans, and enforcement officers often request documentation specific to each jobsite or process.
- They also more frequently require evidence of employee training, including language accessibility for non-English speakers.
- Table 1 Compliance
- Both standards include “Table 1,” which lists common construction tasks and appropriate control methods. Cal/OSHA tends to scrutinize Table 1 compliance more rigorously, especially regarding ventilation effectiveness and proper use of respirators.
- Recordkeeping
- Cal/OSHA requires longer retention periods for air monitoring records, and inspectors more often ask for documentation during site visits.
What Does This Mean for California Employers?
Operating in California means following Cal/OSHA’s stricter interpretation of the rules. Even if you are in compliance with Federal OSHA, that may not be enough to satisfy a Cal/OSHA inspector. For example, Cal/OSHA inspectors are known to ask for:
- Job-specific exposure data (rather than generic or manufacturer-supplied data)
- Air monitoring documentation for every unique work condition
- Comprehensive logs of employee training and respirator fit testing
In California, Cal/OSHA requires silica testing in industries where workers are potentially exposed to respirable crystalline silica above the Action Level (25 µg/m³ as an 8-hour time-weighted average). The requirement applies broadly, but testing is especially relevant in industries where cutting, grinding, drilling, or crushing of silica-containing materials occurs.
Industries Requiring Silica Testing in California
Under Cal/OSHA, silica testing is required when workers may be exposed to levels above the Action Level (25 µg/m³). Industries most affected include:
Construction
- Concrete cutting, drilling, demolition
- Stonework & masonry
- Sandblasting & tunnel work
- Roofing with clay or concrete tiles
Manufacturing
- Stone countertop fabrication
- Glass, brick & tile manufacturing
- Foundries & precast concrete
Mining and Quarrying
- Sand, gravel & aggregate operations
- Rock crushing
Oil and Gas
- Hydraulic fracturing (fracking) involving silica sand
General Industry
- Dental & testing laboratories
- Refractory & paint manufacturing
Shipyards and Maritime
- Abrasive blasting with silica
- Metal grinding & polishing
When Is Silica Testing Required?
Silica testing becomes mandatory if:
- There is no objective data or prior monitoring to prove exposures are below the AL
- New work conditions suggest possible overexposure
- Employers are not fully following Table 1 controls
Compliance Tips for California Employers
To avoid fines and improve worker safety:
- Perform baseline air monitoring before tasks begin
- Update exposure assessments as site conditions change
- Maintain written control plans and Safety Data Sheets (SDS)
- Document and translate all employee training
- Work with a certified industrial hygienist for compliant testing
Why Hire a Silica Testing Expert in California?
While OSHA and Cal/OSHA share a mission of protecting workers, Cal/OSHA is known for stricter enforcement and detailed documentation requirements. Even full compliance with federal standards may fall short in California.
An experienced partner can help:
- Conduct accurate air monitoring
- Prepare compliant exposure control plans
- Train your workforce
- Protect your company from citations and liability
Need Help With Silica Testing?
Healthy Building Science specializes in silica air testing and industrial hygiene services throughout California. We help construction firms, manufacturers, and property managers stay in compliance with both OSHA and Cal/OSHA standards.
Serving San Francisco, the Bay Area, and beyond. Contact us today to schedule an on-site evaluation or silica dust compliance test: Silica Testing Services
