OSHA Rules for Stone Cutting
Quick Definition
OSHA (Occupational Safety and Health Administration) regulates stone cutting safety primarily through the Respirable Crystalline Silica Standard (29 CFR 1926.1153 for construction, 29 CFR 1910.1053 for general industry). The permissible exposure limit (PEL) is 50 micrograms per cubic meter of air averaged over an 8-hour shift. Stone fabrication shops must implement engineering controls (wet cutting, ventilation), provide respiratory protection, offer medical surveillance, and maintain exposure records.
TL;DR
- The silica PEL is 50 ug/m3 averaged over an 8-hour workday - cutting dry stone easily exceeds this
- Wet cutting is the primary control method and is required for most stone cutting operations
- Employers must provide respiratory protection when engineering controls alone are not sufficient
- Medical exams are required for workers exposed above the action level (25 ug/m3) for 30+ days/year
- Penalties for violations can reach $16,131 per violation (serious) or $161,323 per willful violation
- Engineered stone (quartz) contains 90%+ silica and poses the highest risk
- Documentation matters - you must keep exposure records, training logs, and medical surveillance files
The Silica Standard Explained
The OSHA Respirable Crystalline Silica Standard is the most important regulation affecting stone fabrication shops. Here is what it requires:
Exposure Limits
| Measurement | Limit | What It Means |
|---|---|---|
| Permissible Exposure Limit (PEL) | 50 ug/m3 | Maximum average exposure over 8 hours |
| Action Level | 25 ug/m3 | Triggers additional requirements (monitoring, medical exams) |
For context, dry cutting granite can produce silica dust levels of 500-2,000+ ug/m3 - that is 10 to 40 times the legal limit. Dry cutting engineered quartz is even worse because the material is 90-93% crystalline silica.
Who Is Covered
The standard applies to all employers with workers who are or may be exposed to respirable crystalline silica at or above the action level (25 ug/m3). In practical terms, this means every stone fabrication shop in the country.
Required Controls and Compliance Steps
OSHA requires a hierarchy of controls. You must implement engineering controls first, then add respiratory protection if engineering controls alone do not reduce exposure below the PEL.
1. Exposure Assessment
Before anything else, you need to know your shop's silica exposure levels.
Options for assessment:
- Air monitoring - hire an industrial hygienist to measure silica levels at each work station during typical operations
- Table 1 compliance (construction standard) - follow the specific control measures listed in Table 1 for your equipment type, which eliminates the need for air monitoring
- Performance-based approach - demonstrate through monitoring that your controls keep exposure below the PEL
Most fabrication shops benefit from at least one round of professional air monitoring to establish baseline exposure levels.
2. Engineering Controls
These are physical changes to your work environment and processes:
Wet cutting (most critical):
- All bridge saws, CNC machines, and hand tools should use continuous water flow during cutting
- Water suppresses dust at the source - it is the single most effective control
- Maintain adequate water flow rates recommended by equipment manufacturers
- Regularly check and clean water delivery nozzles
Local exhaust ventilation (LEV):
- Dust collection systems at point of generation
- Downdraft tables for hand polishing and finishing work
- Enclosed CNC machine cabins with integrated dust collection
- Regular filter maintenance and replacement
Isolation:
- Enclose high-dust operations where possible
- Separate dry processes (like some polishing) from wet areas
- Use physical barriers between work stations
Housekeeping:
- Wet mopping or HEPA vacuuming - never dry sweeping
- Regular cleaning of surfaces, equipment, and floors
- Compressed air for cleaning is prohibited (it disperses silica dust)
3. Respiratory Protection
When engineering controls cannot reduce exposure below 50 ug/m3, respiratory protection is mandatory.
Minimum requirements:
- Employer must establish a written respiratory protection program (29 CFR 1910.134)
- Workers must be fit-tested for their specific respirator
- Respirators must be NIOSH-approved for silica dust
- Employers must provide respirators at no cost to workers
Respirator selection by exposure level:
| Exposure Level | Minimum Respirator Required |
|---|---|
| Up to 500 ug/m3 (10x PEL) | N95 half-face respirator |
| Up to 1,250 ug/m3 (25x PEL) | P100 half-face or powered air-purifying respirator (PAPR) |
| Up to 2,500 ug/m3 (50x PEL) | Full-face air-purifying respirator with P100 filters |
| Above 2,500 ug/m3 | Supplied air respirator |
See the related article on choosing the right dust mask for stone cutting for specific product recommendations.
4. Medical Surveillance
If workers are exposed above the action level (25 ug/m3) for 30 or more days per year, the employer must provide:
- Initial medical exam within 30 days of initial assignment (or before if possible)
- Periodic exams every 3 years
- Chest X-rays or CT scans as part of the examination
- Pulmonary function testing
- Exams at no cost to the worker, during work hours
The examining physician must be informed about the worker's exposure levels, job duties, and the specific controls in place.
5. Written Exposure Control Plan
Every shop with silica exposure above the action level must maintain a written plan that includes:
- A description of tasks involving silica exposure
- Engineering and work practice controls in use
- The respiratory protection program
- Procedures for restricting access to high-exposure areas
- Housekeeping procedures
This plan must be reviewed and updated as conditions change (new equipment, new materials, process changes).
6. Training and Communication
Workers must receive training on:
- Health hazards of silica exposure, including silicosis, lung cancer, and kidney disease
- Tasks that result in exposure
- Engineering controls and work practices in the shop
- Purpose and proper use of respiratory protection
- The written exposure control plan
- Medical surveillance program and their right to access records
Training must occur at initial assignment and whenever changes affect silica exposure.
Material-Specific Risks
Not all stone materials pose equal silica risk:
| Material | Crystalline Silica Content | Risk Level |
|---|---|---|
| Engineered quartz (Caesarstone, Cambria, etc.) | 90-93% | Very high |
| Granite | 25-60% (varies by type) | High |
| Quartzite | 70-95% | Very high |
| Sandstone | 60-95% | Very high |
| Marble | Less than 5% | Lower (but not zero) |
| Porcelain slabs | 15-30% | Moderate |
| Soapstone | Less than 5% | Lower |
Engineered quartz presents the highest risk because of its extremely high silica concentration. Several countries have restricted or banned dry cutting of engineered stone due to clusters of accelerated silicosis cases among young fabricators.
Common OSHA Violations in Stone Shops
Based on OSHA inspection data, the most frequently cited violations in stone fabrication include:
- Insufficient dust controls - dry cutting or inadequate wet cutting systems
- No respiratory protection program - providing respirators without fit testing or a written program
- Missing medical surveillance - not offering required medical exams
- Inadequate training - no documented silica hazard training
- Poor housekeeping - dry sweeping instead of wet mopping or HEPA vacuuming
- No exposure monitoring - failing to assess or document silica levels
- Missing written exposure control plan
Penalty Structure
OSHA penalties increased in 2024 and are adjusted annually for inflation:
| Violation Type | Maximum Penalty |
|---|---|
| Serious | $16,131 per violation |
| Other-than-serious | $16,131 per violation |
| Willful or repeated | $161,323 per violation |
| Failure to abate | $16,131 per day beyond abatement date |
Multiple violations in a single inspection can stack quickly. A shop with dry cutting, no respiratory program, no training, and no medical surveillance could face $50,000+ in penalties from a single OSHA visit.
Beyond Compliance: Smart Safety Practices
Meeting OSHA minimums is the legal baseline, but shops that prioritize worker safety go further:
Real-time dust monitoring - portable dust monitors that alert workers when levels spike, allowing immediate response before cumulative exposure becomes dangerous.
Water recycling systems - settling tanks and recycling equipment that manage the large volumes of water generated by wet cutting operations while reducing environmental impact and water costs.
Equipment maintenance schedules - worn blades and dull tools generate more dust than sharp ones. Maintaining equipment is a safety measure as much as a quality measure.
Technology adoption - shops using digital workflows reduce the need for repeated dry-finishing tasks. Accurate templates mean fewer remakes, which means less total cutting and less total dust exposure. SlabWise's template verification catches errors before fabrication, and its nesting optimization reduces the total amount of cutting required per job.
State-Specific Regulations
Some states have their own OSHA-approved plans with standards that may be stricter than federal OSHA:
- California (Cal/OSHA) - often implements stricter enforcement and has considered additional engineered stone restrictions
- Washington - has its own occupational safety agency with additional requirements
- Oregon - additional silica-related workplace standards
- Minnesota - enhanced enforcement for silica exposure in fabrication
If your shop operates in a state-plan state, check both federal OSHA and your state's specific requirements.
Frequently Asked Questions
What is the OSHA silica exposure limit for stone fabrication? The Permissible Exposure Limit (PEL) is 50 micrograms per cubic meter of air, averaged over an 8-hour work shift. The action level, which triggers additional requirements, is 25 ug/m3.
Is dry cutting stone illegal? Dry cutting is not explicitly banned by federal OSHA, but it is extremely difficult to comply with the silica PEL while cutting dry. In practice, wet cutting is required for compliance. Some states and countries have moved toward outright bans on dry cutting of engineered stone.
How often does OSHA inspect stone fabrication shops? OSHA conducts both programmed inspections (based on industry targeting) and complaint-driven inspections. Stone fabrication has received increased attention since the updated silica standard took effect. An employee complaint will typically trigger an inspection within days.
Do I need an industrial hygienist to measure silica levels? It is strongly recommended. While not legally required if you follow Table 1 controls exactly, professional air monitoring provides the most reliable exposure data and serves as strong documentation in case of an OSHA inspection.
What if an employee refuses to wear a respirator? Employers have a legal obligation to enforce respiratory protection. If engineering controls do not reduce exposure below the PEL, respiratory protection is mandatory - not optional. Document any refusals and take appropriate corrective action.
Are there OSHA rules specific to CNC stone cutting machines? CNC machines are not called out separately, but they must meet the same silica exposure requirements. Many modern CNC machines include enclosed cutting chambers with integrated water delivery and dust collection, which helps with compliance.
How long do I need to keep exposure records? OSHA requires exposure measurement records to be maintained for at least 30 years. Medical surveillance records must also be kept for 30 years plus the duration of employment.
Does OSHA regulate noise in stone shops? Yes. The noise standard (29 CFR 1910.95) applies to stone fabrication. Bridge saws and CNC machines commonly exceed the 85 dBA action level. Hearing protection and a hearing conservation program are required above this threshold.
What training records does OSHA require? Maintain records of all silica hazard training including dates, topics covered, trainer qualifications, and attendee sign-in sheets. There is no specific retention period in the silica standard, but best practice is to keep records for the duration of employment plus 30 years.
Can employees sue my shop for silica exposure? Workers' compensation typically covers occupational illnesses, limiting direct lawsuits. However, in cases of egregious negligence, additional legal action may be possible. Compliance with OSHA standards is your best legal protection.
What is the difference between the construction and general industry silica standards? The construction standard (1926.1153) includes Table 1, which provides specific control measures for common tasks. The general industry standard (1910.1053) requires exposure assessment but does not include a Table 1 equivalent. Most stone fabrication falls under general industry, but field installation work may fall under construction.
How has OSHA enforcement of silica rules changed recently? Enforcement has intensified significantly since 2018 when the updated standard took full effect. High-profile silicosis cases among young engineered stone workers have led to increased inspections and political pressure for even stricter standards.
Protect Your Workers and Your Business
OSHA compliance is not optional, and the health consequences of silica exposure are severe and irreversible. Beyond safety, running an efficient shop reduces total dust exposure - fewer remakes mean less cutting, and better nesting means less material to process. SlabWise helps fabrication shops eliminate remakes through 3-layer template verification and reduce total cutting volume through optimized nesting. Start your 14-day free trial and build a safer, more productive shop.
Sources
- OSHA - Respirable Crystalline Silica Standards (29 CFR 1910.1053, 29 CFR 1926.1153)
- OSHA - Respiratory Protection Standard (29 CFR 1910.134)
- NIOSH - Criteria for a Recommended Standard: Occupational Exposure to Crystalline Silica
- American Conference of Governmental Industrial Hygienists (ACGIH) - Silica TLV Documentation
- Natural Stone Institute - Silica Safety Resources
- OSHA - Penalty Amounts (Annual Adjustment)
- Cal/OSHA - Silica in Stone Fabrication Fact Sheet
- CDC/NIOSH - Silicosis Surveillance Data