Health hazards from silica exposure

• Long-term exposure to airborne crystalline silica (for example, quartz) can cause a disabling, sometimes fatal lung disease called silicosis.
• Exposure to crystalline silica has been linked to lung cancer.
• When the dust is inhaled deep into the lungs, microscopic particles of silica can cause scar tissue to form in the lung tissue, which restricts the lungs’ ability to extract oxygen from the air. This damage is permanent, but symptoms of the disease may not appear for many years.
• The disease initially causes fatigue and shortness of breath. If exposure continues, it can lead to chest pain, heart problems (difficulty breathing can strain the heart), and respiratory failure.
• Exposure to crystalline silica has also been linked to other diseases, including bronchitis and tuberculosis.

Purpose and responsibilities

• MB Electrical has a duty to protect our workers from silica exposure during concrete cutting. Studies show that concrete cutting generates airborne silica levels well in excess of safe levels. Effective controls are available to protect workers from harmful exposure.
• A combination of control measures will be required to achieve this objective. We commit to being diligent in our efforts to select the most effective control technologies available, and to ensure that the best practices, as described in this exposure control plan (ECP), are followed at our worksites.
• The work procedures we establish for cutting concrete will protect not only our workers but also any other workers on-site who are not involved in these operations.

The employer is responsible for the following:

• Ensure that the materials (for example, tools, equipment, and personal protective equipment [PPE]) and other resources (for example, worker training) required to fully implement and maintain this ECP are readily available.
• Ensure that supervisors and workers are educated in the hazards of silica exposure and trained to work safely with silica.
• Maintain written records of training (for example, proper use of respirators), fit-test results, crew talks, and inspections (for equipment, PPE, and work methods and practices).
• Conduct an annual review (or more often if conditions change) of the effectiveness of the ECP. This includes a review of available dust control technologies to ensure these are selected and used when practical.
• Coordinate work with the prime contractor and other employers to ensure a safe work environment.

Supervisors are responsible for the following:

• Provide adequate instruction to workers on the hazards of silica associated with concrete cutting.
• Select and implement the appropriate control measures.
• Ensure that workers using respirators have been properly trained and fit-tested and that the results are recorded.
• Ensure that work is conducted in a manner that minimizes and adequately controls the risk to workers and others. This includes ensuring that workers use appropriate engineering controls and wear the necessary PPE.

Workers are responsible for the following:

• Use the assigned protective equipment in an effective and safe manner.
• Follow established work procedures as directed by the supervisor.
• Report any unsafe conditions or acts to the supervisor.
• Report to the employer any exposure incidents or any signs or symptoms of silica illness.

Risk identification and assessment

• Concrete can contain a high percentage of silica.
• Cutting concrete without the use of proper dust controls and PPE can expose workers to levels of airborne respirable crystalline silica that are above the exposure limit listed in the Regulation.
• Work locations where workers or other persons are exposed to the hazards of silica will be identified with signs, placards, or barrier tape.

Exposure limit

• The occupational exposure limit (OEL) for respirable crystalline silica (including quartz) is 0.025 milligrams per cubic metre (mg/m3).
• Because crystalline silica is linked to lung cancer, workplace exposures must be reduced to levels that are As Low As Reasonably Achievable (ALARA) below the OEL.

Silica dust control

The Regulation requires employers to select silica dust controls based on the following hierarchy:

1. Engineering (for example, local exhaust ventilation or water attachments)
2. Administrative controls (for example, cutting when other workers are not in the area)
3. Personal protective equipment (for example, respirators and disposable coveralls)

• Use of respirators as a primary control is not acceptable when other methods are available and practical.
• Respirators will be used in conjunction with other controls such as local exhaust ventilation (LEV) or water attachments to reduce worker exposure to silica, unless air monitoring information suggests otherwise.
• LEV, HEPA attachments, and wet drilling are the preferred engineering methods, and will be used when practicable.
• A HEPA vacuum will be used for cleanup and decontamination.

Procedure - Acceptable control methods for concrete drilling:

• The work methods in the following table are acceptable, provided that the respirator selection, dust suppression, and other controls are adhered to.
• The following control options will be used to eliminate or reduce the risk to workers from the hazards of silica dust exposure, unless air monitoring information suggests otherwise:

Safe work planning

• Select one or more of the methods described in the table above.
• Establish a barrier or full enclosure (under negative pressure) around the work zone to restrict access by unprotected workers.
• Inspect all dust control equipment and tools to make sure they are in good working order.
• Use and maintain all tools and equipment as specified by the manufacturer. For example, test the effectiveness of HEPA filters using dioctyl phthalate (DOP) testing or similar means at least annually, and any time a HEPA filter is replaced in a vacuum cleaner or ventilation system.
• When working on a multi-employer site, provide the general contractor with a copy of the silica exposure control plan and safe work procedures. Review the procedures and work schedule with the general contractor to determine if additional measures are required to reduce worker exposure to silica.
• Ensure that workers inspect their respirators before start-up. 
• Visually monitor dust release from equipment during use. When tools and equipment are working properly, very little dust should be visible in the air. Stop work if excessive dust is observed.

Respiratory protective equipment

All respirator selection, cleaning, maintenance and storage will follow the Respiratory Code of Practice.

 Other personal protective equipment and hygiene

• Workers will wear approved safety goggles and hearing protection when drilling concrete. This equipment will not interfere with the fit of the worker’s respirator.
• Workers will wear washable work coveralls that do not retain dust. These coveralls will be laundered and changed regularly, and workers will not wear them outside the work area. For example, workers must remove coveralls before eating lunch.
• Workers who launder clothing contaminated with silica should be informed of the hazards of silica and the precautions required for handling the clothing.
• Disposable coveralls will be used in full enclosure systems.

 Housekeeping procedures

• Dry sweeping and the use of compressed air are prohibited for removing dust and debris containing silica. Work areas and equipment covered by dust will be cleaned at the end of every shift using a HEPA filter vacuum. 
• Wet cleanup may also be used to remove dust.
• Any slurry generated by wet control methods should be cleaned up when the work is completed to avoid secondary dust exposure hazard.
• Waste material will be placed in a dumpster and will be removed at least weekly. The location and method used to store waste will not allow silica-containing dust to re-enter the workplace.
• Supervisors are responsible for ensuring that work areas are free from dust at the end of each shift.

 Worker training for silica dust exposure

• Training will be performed by the employer or the employer’s designate.
• Records of attendance, dates of training, and training material will be documented and retained.
• Additional training or reference material on silica dust exposure will be made available to employees upon request.

 Training topics 

• Health hazards of silica dust exposure (including signs and symptoms of silicosis)
• Operations and materials that can produce silica dust exposures
• Engineering controls and safe work practices used to protect workers
• The importance of proper equipment control and maintenance
• Housekeeping procedures
• Proper use of respirators and the respirator program
• Personal hygiene procedures to reduce exposures
• How smoking increases the risk of developing silicosis and other lung damage
• The details of the exposure control program for silica dust

 Health surveillance 

• Workers who are regularly exposed to silica dust will receive regular medical examinations from their family physicians. These examinations may include chest X-rays. 
• Workers will report any symptoms of silica exposure to the employer and WorkSafeBC for tracking and investigation.