Silica Dust Control and Respiratory Protection

Document Number: [SWP-NUMBER]

Revision Date: [DATE]

Next Review Date: [NEXT REVIEW DATE]

Department: [DEPARTMENT NAME]

1. Scope

This safe work procedure (SWP) outlines the requirements for controlling exposure to respirable crystalline silica dust during construction activities. It applies to all tasks where materials containing silica are disturbed, such as cutting, grinding, drilling, and demolition. The goal is to minimize worker exposure to silica dust and comply with OSHA regulations. This SWP does not cover abrasive blasting, which requires specific procedures and registration.

2. Definitions

Respirable Crystalline Silica Quartz, cristobalite, and/or tridymite contained in airborne particles that are determined to be respirable by a sampling device designed to meet the characteristics for respirable-particle-size- selective samplers specified in the International Organization for Standardization (ISO) 7708:1995. [2]

Permissible Exposure Limit (PEL) The maximum concentration of an airborne contaminant to which a worker may be exposed, averaged over an 8-hour period. Assigned Protection Factor (APF) A measure of the effectiveness of a respirator in reducing a worker's exposure to airborne contaminants.

3. Responsibilities

3.1 Supervisors

• Ensure workers are trained and competent in the safe work procedures for tasks involving silica exposure.
• Provide appropriate respiratory protection and ensure it is properly used and maintained.
• Monitor the work environment for silica dust levels and implement necessary control measures.
• Enforce the use of required PPE and adherence to safe work practices.
• Ensure proper cleaning and disposal of silica-containing materials.

3.2 Workers

• Use and maintain respiratory protection as required by this procedure and training.
• Participate in training programs related to silica dust exposure and control measures.
• Report any concerns regarding silica dust exposure or control measures to the supervisor.
• Follow safe work procedures and use control equipment properly.
• Remove work clothes and clean them properly before leaving the work area.

3.3 Health and Safety Representative

• Participate in workplace inspections to identify silica hazards.
• Assist in the development and review of safe work procedures related to silica exposure.
• Provide guidance and support to workers and supervisors on silica-related safety issues.

4. Potential Hazards and Risks

Hazard	Risk	Control Measures
Cutting concrete or masonry with a stationary saw [4]	Exposure to high levels of respirable crystalline silica dust, potentially leading to silicosis or other respiratory illnesses.	Use stationary saw equipped with integrated water delivery system that continuously feeds water to the blade. Operate and maintain tool in accordance with manufacturer's instructions to minimize dust emissions.
Cutting concrete or masonry with a handheld power saw [4]	Inhalation of respirable crystalline silica dust, potentially leading to silicosis or other respiratory illnesses.	Use saw equipped with integrated water delivery system that continuously feeds water to the blade. When used indoors or in an enclosed area, respiratory protection with a minimum APF of 10 is required. Operate and maintain tool in accordance with manufacturer's instructions to minimize dust emissions.
Jackhammering and handheld powered chipping tools [5]	Exposure to high concentrations of respirable crystalline silica dust, potentially leading to acute or chronic silicosis.	Use tool with water delivery system that supplies a continuous stream or spray of water at the point of impact. When used indoors or in an enclosed area, respiratory protection with a minimum APF of 10 is required. Alternatively, use tool equipped with commercially available shroud and dust collection system.
Handheld grinders for mortar removal (tuck-pointing) [9]	Inhalation of respirable crystalline silica dust, potentially leading to silicosis.	Use grinder equipped with commercially available shroud and dust collection system. Dust collector must provide 25 cubic feet per minute (cfm) or greater of airflow per inch of wheel diameter and have a filter with 99% or greater efficiency and a cyclonic pre-separator or filter-cleaning mechanism. Respiratory protection with a minimum APF of 10 is required.
Walk-behind milling machines and floor grinders [10]	Exposure to respirable crystalline silica dust, potentially leading to respiratory illnesses.	Use machine equipped with integrated water delivery system that continuously feeds water to the cutting surface or use machine equipped with dust collection system recommended by the manufacturer. When used indoors or in an enclosed area, use a HEPA-filtered vacuum to remove loose dust in between passes.
Handheld and stand-mounted drills (including impact and rotary hammer drills) [7]	Inhalation of respirable crystalline silica dust, potentially leading to silicosis.	Use drill equipped with commercially available shroud or cowling with dust collection system. Dust collector must provide the air flow recommended by the tool manufacturer, or greater, and have a filter with 99% or greater efficiency and a filter-cleaning mechanism. Use a HEPA-filtered vacuum when cleaning holes.

5. Personal Protective Equipment (PPE)

All personal protective equipment (PPE) must be inspected before each use to ensure it is in good condition.

• Safety Goggles: Provides eye protection against dust and debris. Ensure goggles fit properly and are compatible with other PPE.
• Respirator: Protect the respiratory system from inhaling silica dust. The respirator must provide a minimum APF of 10 and be equipped with a 100 series or HEPA high-efficiency filter. Select, use, and care for the respirator in accordance with CAN/CSA Standard Z94.4-11. [1] [1]
• Protective Clothing: Coveralls and headgear that exclude silica dust. Maintain and clean the clothing in a safe manner. [3]
  • Ensure clothing is properly fitted.
  • Inspect clothing for damage before use.
  • Clean or dispose of clothing properly after use.
• Gloves: Use suitable protective gloves if risk of skin contact. [8]

Respirators must be inspected before each use to ensure a proper fit and that the filters are not damaged or expired. Protective clothing should be inspected for tears or damage that could compromise its effectiveness.

6. Equipment and Tools

All equipment and tools used for tasks involving silica exposure must be regularly inspected and maintained in good working order.

• HEPA Vacuum: Use a vacuum cleaner equipped with a high-efficiency filter to clean work areas and equipment. Ensure the vacuum is properly maintained and the filter is regularly replaced. [6]
• Wet Cutting Tools: Use tools equipped with integrated water delivery systems to suppress dust during cutting, grinding, and drilling operations. Ensure the water flow is sufficient to minimize dust generation.
• Dust Collection Systems: Use tools equipped with commercially available dust collection systems to capture dust at the source. Ensure the dust collector has a filter with 99% or greater efficiency and a filter-cleaning mechanism.

Inspect all equipment, including saws, grinders, drills, and dust collection systems, to ensure they are in good working order. Check water delivery systems for proper flow and dust collection filters for cleanliness and integrity.

7. Pre-Job Requirements

7.1 Training and Competency

Training: Workers must be trained and informed of the risks, prevention methods, and safe working methods before undertaking work that exposes them to crystalline silica dust. The training program must be established in writing and include information on the materials presumed to contain crystalline silica, the effects of exposure to crystalline silica dust on health, safe working methods and procedures, the use and care of control equipment and tools for crystalline silica dust, and the wearing and care of individual and common protective equipment. [1] [6]

7.2 Pre-Job Briefing

Pre-Job Briefing: Conduct a pre-job briefing with all workers involved to discuss the SWP, potential hazards, control measures, and emergency procedures. Ensure all workers understand their roles and responsibilities.

7.3 Work Area Preparation

Ventilation: Ensure adequate ventilation in the work area to minimize the accumulation of visible airborne dust, especially when working indoors or in enclosed spaces. Use a means of exhaust as needed. [11]

8. Safe Work Procedure Steps

1. Equipment Inspection: Inspect all equipment, including saws, grinders, drills, and dust collection systems, to ensure they are in good working order. Check water delivery systems for proper flow and dust collection filters for cleanliness and integrity.
2. Work Area Preparation: Ensure the work area is well-ventilated. For indoor tasks, use exhaust fans to minimize dust accumulation. Wet down surfaces to further suppress dust.
3. Wet Cutting/Grinding: When using tools such as saws, grinders, or drills, use the integrated water delivery system to continuously wet the material being cut or ground. Ensure water flow is sufficient to minimize dust generation.
4. Dust Collection Systems: If wet methods are not feasible or sufficient, use tools equipped with commercially available dust collection systems. Ensure the dust collector has a filter with 99% or greater efficiency and a filter-cleaning mechanism.
5. Respiratory Protection: Wear a properly fitted respirator with a minimum APF of 10 and equipped with a HEPA filter. Ensure the respirator is selected, used, and maintained in accordance with applicable standards.
6. Cleaning Procedures: Use a HEPA-filtered vacuum to clean the work area regularly. Avoid dry sweeping or using compressed air, as these methods can cause dust to become suspended in the air. [6]
7. Work Clothes Cleaning: Before leaving the work area, remove work clothes and place them in a closed bag supplied by the employer or clean them using either a wet cloth or a vacuum cleaner equipped with a high-efficiency filter. [6]
8. Debris Disposal: Properly dispose of debris of materials presumed to contain or containing crystalline silica that is liable to become dispersed in the air by wetting or placing it in closed containers and clearly identifying them. [6]

9. Precautions and Safety Measures

• Isolate workers from the source of dust emissions where possible. [1]
• Confine the source of dust emissions so that workers are not exposed. [1]
• Maintain equipment used to control dust in accordance with the manufacturer's instructions or a standard offering equivalent safety. [1]
• Ensure that all places where silica dust may accumulate are regularly cleaned using vacuum methods wherever practicable. [3]
• Warn workers of the danger to their health of inhaling silica dust and that the risk of injury is made greater by smoking. [3]

10. Emergency Procedures

10.1 General Emergency Response

In case of a medical emergency, immediately provide first aid and seek medical attention. Ensure that the injured worker is transported to a medical facility for further evaluation and treatment.

10.2 Specific Emergency Scenarios

• Worker experiences difficulty breathing or other respiratory symptoms: Immediately leave the area and seek fresh air. Report the incident to the supervisor and safety personnel. Undergo a medical evaluation to assess any potential respiratory effects.
• Silica dust enters the eyes: Flush eyes with water for at least 15 minutes. Seek medical attention if irritation persists.
• Silica dust comes into contact with skin: Wash the affected area with soap and water. Seek medical attention if irritation develops.

10.3 Emergency Contact Information

Emergency contact information should be readily available on site.

11. Incident Reporting and Investigation

All incidents, including near misses, must be reported to the supervisor immediately. A written report must be submitted within 24 hours of the incident. The report should include details of the incident, the cause, and any corrective actions taken.

A thorough investigation will be conducted to determine the root cause of the incident. The investigation team will include safety personnel, supervisors, and workers. Corrective actions will be implemented to prevent recurrence.

Approved by: [NAME AND POSITION]

Date: [APPROVAL DATE]

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