Silica, Crystalline: Controlling Silica Dust in Construction
Overview of Topic
Crystalline silica, a common mineral found in many naturally occurring materials and used in various construction products, can become respirable dust when cut, sawed, or ground. OSHA’s regulation (29 CFR 1926.1153) addresses the control of respirable crystalline silica dust to prevent silicosis, a serious lung disease, as well as other silica-related illnesses.
Inspection Before Use Requirements
Before beginning work that generates silica dust, inspect:
- All equipment and tools for proper function and fit of integrated water delivery systems or dust collection systems.
- The availability and condition of respirators when required.
- The type of silica-containing materials to be worked on and the potential for dust generation.
Regular inspections and maintenance of equipment used for dust control are crucial to ensure their effectiveness.
Use Requirements
- Water Delivery Systems: Use tools equipped with integrated water delivery systems that can continuously feed water to the cutting surface. This suppresses dust before it becomes airborne.
- Dust Collection Systems: Use tools with dust collection systems and HEPA filters to capture and remove dust from the air.
- Work Practices: Minimize the number of workers in the immediate area of silica dust-generating activities. Implement work practices that limit dust exposure, such as wet cutting or using local exhaust ventilation.
General Industry Rules Applicable to Construction
In addition to specific construction standards, general industry rules (1910.1000) for air contaminants also apply to the control of silica dust:
- Exposure limits must not exceed OSHA’s permissible exposure limit (PEL) for respirable crystalline silica, which is 50 micrograms per cubic meter of air (50 µg/m³) as an 8-hour time-weighted average (TWA).
- Employ engineering controls and work practices to limit worker exposure.
- Provide respiratory protection when necessary.
Other Safety Rules
- Medical Surveillance: Workers exposed to silica above the action level for 30 or more days per year must have access to medical exams every three years.
- Training and Information: Employers must train workers on the health hazards associated with silica exposure and proper use of controls and protective equipment.
- Housekeeping: Avoid dry sweeping or using compressed air to clean up silica dust. Instead, use wet methods or HEPA-filtered vacuuming.
Specific Regulations
- Exposure Control Plan: Develop and implement a written exposure control plan that identifies tasks that involve exposure and methods used to protect workers.
- Competent Person: Designate a competent person to implement the written exposure control plan.
Employee Training
Training for workers should include:
- Health Hazards: Detailed information on the lung diseases related to silica dust, including silicosis and lung cancer, emphasizing the importance of minimizing exposure.
- Exposure Operations: Identification of construction operations and materials likely to generate silica dust, such as cutting and grinding concrete or masonry, sandblasting, and other similar activities.
- Exposure Limits: Explanation of OSHA’s permissible exposure limit (PEL) for silica and the necessity of staying below these levels through the use of engineering controls and protective equipment.
- Control Methods: Training on the proper usage of water delivery systems, dust collection systems, respirators, and other protective equipment. Emphasize routine checks and maintenance to ensure effectiveness.
- Maintenance and Housekeeping: Importance of regular maintenance of equipment to prevent breakdowns and reduce dust exposure. Instruction on safe housekeeping practices that do not disperse dust into the air.
Training Tips
- Use real-life scenarios and examples from your worksite to illustrate points during training sessions.
- Regularly review and update training materials to reflect the most current information and regulatory changes.
Where to Go for More Information
Adhering to these practices not only helps in complying with regulations but also significantly reduces health risks associated with silica exposure. Ensure all protective measures are in place and followed to maintain a safe work environment.
