Respirable crystalline silica — the fine dust generated when silica-containing materials are cut, ground, drilled, or blasted — causes silicosis, an incurable and progressive lung disease. It also causes lung cancer, kidney disease, and COPD. OSHA’s respirable crystalline silica standards — 29 CFR 1910.1053 for general industry and 29 CFR 1926.1153 for construction — established enforceable exposure limits and compliance requirements that have been in full effect for years.
For facilities that hire outside blasting contractors, this isn’t just the contractor’s problem. The exposure occurs on the facility’s property, often near facility employees. The abrasive the contractor uses, the containment they set up, and the respiratory protection program they maintain all directly affect the facility’s regulatory exposure and the health of anyone in the area.
The Regulatory Framework
Permissible Exposure Limit
OSHA’s silica PEL is 50 micrograms of respirable crystalline silica per cubic meter of air (50 μg/m³) as an 8-hour time-weighted average (TWA). This is a significant reduction from the previous limits (which varied and were calculated differently) and reflects the scientific evidence on health outcomes at lower exposure levels.
The action level — the concentration at which the full suite of OSHA compliance requirements is triggered — is 25 μg/m³ as an 8-hour TWA.
Table 1 for Construction Operations
OSHA’s construction silica standard includes Table 1, which specifies engineering controls and respiratory protection for specific tasks and equipment configurations. When a contractor follows Table 1 controls for a listed task — for example, using a vacuum shroud or wet methods with specific equipment configurations — they are presumed to be in compliance without requiring exposure monitoring.
Abrasive blasting appears in Table 1 only for specific controlled configurations (wet blasting or use of a blast machine in an enclosed or ventilated blasting cabinet). Open abrasive blasting on structural steel, seawalls, tanks, and industrial equipment does not fall under a Table 1 control that presumptively satisfies the PEL. Contractors performing open abrasive blasting must conduct exposure monitoring to determine whether PEL compliance is achieved.
General Industry Requirements
For blasting operations classified under general industry (manufacturing plant maintenance, industrial facility work), the full general industry silica standard applies. The required elements when exposure is at or above the action level:
- Written exposure control plan
- Designation of a competent person to implement the plan
- Air monitoring or objective data demonstrating exposure levels
- Engineering and work practice controls to reduce exposure below the PEL
- Respiratory protection when controls cannot achieve the PEL
- Medical surveillance for workers exposed at or above the action level for 30 or more days per year
- Silica hazard training for exposed workers
- Recordkeeping for exposure measurements, medical surveillance, and training
The Role of Abrasive Selection
The abrasive a blasting contractor uses is the single largest variable in silica exposure for abrasive blasting operations. Coal slag — the most widely used and least expensive abrasive in the industry — contains crystalline silica at concentrations that trigger the full OSHA silica compliance requirements. When coal slag fractures on impact during blasting, it generates fine respirable dust that carries silica particles.
Silica-free abrasives — garnet, aluminum oxide, steel grit, engineered mineral abrasives — eliminate the silica exposure pathway from the abrasive itself. The substrate being blasted may still contain silica (concrete, masonry, silica-containing steel), which must be addressed through exposure monitoring and controls regardless of abrasive selection. But eliminating silica from the abrasive is the most direct way to reduce the primary exposure source in abrasive blasting.
Facilities should ask any blasting contractor what abrasive they use. A contractor using coal slag on your property is generating silica exposure that must be monitored and controlled — not just for their own workers, but potentially for facility employees in adjacent areas.
What Facilities Need to Know About Contractor Work on Their Property
The Multi-Employer Worksite Rule
OSHA’s multi-employer worksite policy establishes that more than one employer can be cited for a hazard on a shared worksite. The creating employer (who generates the hazard), the exposing employer (whose employees are exposed), the correcting employer (responsible for correcting the hazard), and the controlling employer (who has supervisory authority over the worksite) can each bear compliance obligations.
A facility that hires a blasting contractor and exercises control over how work is performed — scheduling, access, adjacency to facility employees — can be a controlling employer with OSHA compliance obligations regarding silica exposure generated by the contractor’s work. This is not a theoretical liability. OSHA has cited facility owners and general contractors as controlling employers when subcontractor work created hazardous exposures for workers they didn’t directly employ.
The practical implication: facilities that hire blasting contractors should require evidence that the contractor’s silica compliance program is in order before work begins on their property.
What to Require from a Blasting Contractor
Before authorizing abrasive blasting work at a facility, request and review:
Written Exposure Control Plan (ECP). The OSHA silica standard requires a written ECP that identifies tasks involving silica exposure, the engineering controls and work practices used to reduce exposure, and the housekeeping measures in place. If the contractor doesn’t have a written ECP, they are not in compliance with the standard.
Abrasive specification. Confirm what abrasive will be used and its silica content. Request the Safety Data Sheet (SDS) for the abrasive. A silica-free abrasive eliminates the primary exposure pathway.
Respiratory protection program. What respirators are workers using and under what circumstances? Abrasive blasting operations require air-supplied respirators for blast operators — not just N95 particulate masks. The contractor should have a written respiratory protection program compliant with OSHA 29 CFR 1910.134 that includes fit testing and medical evaluation for respirator users.
Exposure monitoring data. Has the contractor conducted air monitoring for silica on comparable projects? What were the results? Contractors with multiple projects on record should have monitoring data demonstrating their control measures achieve PEL compliance.
Competent person designation. OSHA requires a competent person — someone capable of identifying silica hazards and authorized to take corrective action — to implement the ECP on each project. Who is that person for your project?
Protecting Facility Employees During Blasting Work
When abrasive blasting occurs inside an operating facility or adjacent to areas where facility employees work, the facility has a direct obligation to protect its own employees from silica exposure generated by the contractor’s work.
Practical controls:
- Establish and enforce exclusion zones around active blasting operations sufficient to prevent facility employees from entering areas where silica dust concentrations may be above the action level.
- Coordinate scheduling to conduct blasting during periods when adjacent facility areas are unoccupied — night shifts, weekends, planned shutdowns.
- Verify containment before blasting begins to confirm that dust will not migrate to occupied areas through HVAC systems, open doorways, or gaps in temporary enclosures.
- Communicate with facility employees who work near blasting operations about the hazard, the controls in place, and what to do if they observe dust migrating beyond the controlled area.
Enforcement Trends
OSHA silica enforcement has intensified since the standards reached full implementation. The construction silica standard reached full enforcement in 2018; general industry reached full enforcement in 2021. Inspections targeting silica-generating operations — including abrasive blasting — are conducted both programmatically and in response to complaints.
Penalties for silica violations under OSHA’s current penalty structure can reach $16,550 per serious violation and $165,514 per willful or repeated violation. Citations that name facility owners as controlling employers on projects where contractor work generated excessive silica exposure have occurred.
The compliance investment — silica-free abrasives, engineered containment, supplied-air respirators, written programs, and monitoring — is straightforward for a contractor running a professional operation. For a facility, the due diligence investment in verifying contractor compliance before the project starts is equally straightforward.
Blasting Jack uses premium silica-free abrasives on every project and maintains a full OSHA silica compliance program including written ECP, respiratory protection, and air monitoring capability. For facilities with questions about silica compliance on blasting projects, contact us before work begins.