Silica Exposure Prevention Program

Purpose and Objectives 

The Silica Exposure Prevention Program is an important part of the company’s commitment to protect the health and safety of employees. It is written in accordance with OSHA’s final rule on Respirable Crystalline Silica, 29 CFR 1910.1053 and 1926.1153, and is intended to ensure that exposures are prevented.

Responsibilities 

Respirable silica poses a significant risk. All personnel involved in operations that could potentially create silica dust must take specific actions to ensure that a hazard is not created. 

The company is responsible for: 

• Ensuring that all materials, and other resources required to fully implement and maintain this exposure prevention program, are readily available where and when they are required. 
• Providing a site-specific health and safety plan for each project that outlines the work in detail along with the methods and practices that will be followed on each site. Considerations will include: 
• Availability and delivery of all required tools and equipment 
• Scope and nature of grinding/demolition work to be conducted 
• Control methods to be used 
• Level of respiratory protection required 
• Coordination plan 
• Conducting a periodic review of the effectiveness of the exposure prevention program. That includes a review of the available dust-control technologies to ensure they are selected and used when needed. 
• Initiating the sampling of worker exposure to silica when there are non-standard work practices for which the control methods are not proven to be adequately protective. 
• Ensuring that all required tools, equipment, and personal protective equipment are readily available and used as required by the site-specific health and safety plan. 
• Ensuring supervisors and workers are educated and trained to an acceptable level of competency. 
• Maintaining records of training, respirator fit-test results, crew safety meetings, and inspections (equipment, PPE, work methods/practices). 
• Coordinating the work with the primary contractor and other employers to ensure a safe work environment. 

Supervisors are responsible for: 

• Obtaining a copy of the site-specific health and safety plan and making it available at the worksite. 
• Selecting, implementing, and documenting the appropriate site-specific control measures. 
• Providing adequate instruction to workers on the hazards of working with silica-containing materials (e.g., concrete), and on the precautions specified in the job-specific plan covering hazards at the location. 
• Ensuring that workers have been fit-tested, are using the proper respirators, and that the results are recorded. 
• Directing the work in a manner that ensures the risk to workers is minimized and adequately controlled. 
• Communicating with the primary contractor and other sub-contractors where applicable to ensure a safe work environment. 

The employees are responsible for: 

• Knowing the hazards of silica dust exposure (after training has occurred). 
• Using the assigned protective equipment in an effective and safe manner. 
• Setting up the operation in accordance with the site-specific safety plan. 
• Following established work procedures as directed by the supervisor. 
• Reporting any unsafe conditions or acts to the supervisor. 
• Knowing how and when to report exposure incidents. 

The Health and Safety Director is responsible for reviewing and evaluating the effectiveness of the written exposure plan at least annually and: 

• Updating as necessary 
• Conducting frequent and regular inspections of job sites, materials, and equipment to implement the written exposure prevention program 
• Providing access to SDSs of materials containing silica in accordance with 29 CFR 1910.1200 
• Training employees in accordance with 29 CFR 1910.1053 and 1926.1153 

Definitions 

Action Level: A concentration of airborne respirable crystalline silica of 25/µg/m3, calculated as an 8-hour time-weighted average which requires preventative action to be taken by the employer. 

Contamination Reduction Zone (CRZ): The work zone which represents the transition area between the exclusion zone and the support zone. 

Exclusion Zone (EZ): The work zone which represents the area of highest contamination at the site and/or the area with the greatest risk of exposure to safety hazards including silica. 

Permissible Exposure Limit (PEL): The maximum amount or concentration of a chemical that a worker may be exposed to under OSHA regulations as a time-weighted average. 

Physician or Other Licensed Health Care Professional (PLHCP): An individual whose legally permitted scope of practice allows him or her to independently provide, or be delegated the responsibility to provide, some or all of the necessary health care services required. 

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. 

Silicosis: Lung fibrosis caused by the inhalation of dust containing silica. 

Support Zone: The work zone just outside the contamination reduction zone which represents the clean areas established at the site. 

Silica Background Information 

Crystalline silica is a basic component of soil, sand, granite, and many other minerals. Quartz is the most common form of crystalline silica. Cristobalite and tridymite are two other forms of crystalline silica. All three forms may become respirable-sized particles when workers chip, cut, drill, or grind objects that contain crystalline silica. 

Silica is a one of several chemicals included in the larger classification of silicon dioxide (SiO2). Silicon dioxide is a chemical compound that includes crystalline silica (sand and quartz), amorphous silica (noncrystalline), and silicates (aluminum silicate). Crystalline silica is the basic component of sand, quartz, and granite rock. That form of silica is obtained from the Earth’s crust through mining. Crystalline silica can be processed into other materials including silica flour. Silica flour is produced through the milling of crystalline silica into a fine powder. 

Silicates are compounds that contain silicon dioxide and elements such as aluminum, iron, potassium, magnesium, and/or calcium. Silicates exist in fibrous and non-fibrous forms. Examples of non-fibrous forms include Portland cement, talc, mica, soapstone, and clays. 

At least 1.7 million U.S. workers are exposed to respirable crystalline silica in a variety of industries and occupations including construction, sandblasting, and mining. Silicosis, an irreversible but preventable disease, is the illness closely associated with occupational exposure to the material which also is known as silica dust. Occupational exposures to respirable crystalline silica are associated with the development of silicosis, lung cancer, pulmonary tuberculosis, and airways diseases. Those exposures may also be related to the development of autoimmune disorders, chronic renal disease, and several other adverse health effects.

Health Hazards 

Crystalline silica dust can cause a chronic, sometimes disabling, and even fatal disease called silicosis. The fine particles are deposited in the lungs which causes a thickening and scarring of the lung tissue. The scar tissue restricts the ability of the lungs to extract oxygen from the air. This damage is permanent but symptoms of the disease may not appear for many years. 

A worker may develop any of three types of silicosis, depending on the concentrations of silica dust and the duration of exposure: 

• Chronic Silicosis — develops after 10 or more years of exposure to crystalline silica at relatively low concentrations 
• Accelerated Silicosis — develops 5 to 10 years after initial exposure to crystalline silica at high concentrations 
• Acute Silicosis — develops within a few weeks, or 4 to 5 years, after exposure to very high concentrations of crystalline silica 

Initially, workers with silicosis may have no symptoms. However, as the disease progresses, a worker may experience: 

• Shortness of breath 
• Severe cough 
• Weakness 

Exposure to silica has also been linked to other diseases, including bronchitis, tuberculosis, and lung cancer. 

Hazard Identification 

In order to protect workers from hazardous silica dust, the site-specific health and safety plan will identify tasks in which silica may become airborne and become a risk. Those activities may include but are not limited to: 

• Chipping, hammering, and drilling of rock 
• Crushing, loading, hauling, and dumping of rock 
• Abrasive blasting using an abrasive containing silica or sand 
• Abrasive blasting of or on concrete (regardless of the abrasive used) 
• Sawing, hammering, drilling, grinding, and chipping of concrete or masonry 
• Demolition of concrete and masonry structures 
• Dry sweeping or pressurized air blowing of concrete, rock, or sand dust. 

As conditions change on the jobsite, the identification of potential silica exposure to workers should be examined. 

Exposure Assessments 

Exposure assessments must be conducted for employees who may potentially be exposed to crystalline silica at or above the action level. Assessments may be performed by conducting personal monitoring or taking a representative sample from employees working in the same area and conducting similar tasks.

Exposure assessments should only be conducted by trained and qualified individuals who understand industrial hygiene techniques. 

The exposure assessment will be conducted using sampling methods which assess the 8-hour TWA exposure for each employee. Exposure monitoring should be conducted initially and breathing zone air samples should be used that are reflective of the exposure of employees on each shift, job classification, and in each work area. In cases where several employees conduct the same task, a representative fraction of these employees will participate in sampling in order to meet the requirement. 

Based on the results of initial sampling, if monitoring indicates that the employee exposures are below the action level, monitoring will be discontinued for those tasks and work areas that were sampled. 

If sampling results indicate that exposures are at or above the action level (AL), but below the permissible exposure limit (PEL), the monitoring shall be repeated within six months of the most recent monitoring. 

When sampling results indicate that exposures are above the PEL, monitoring will be repeated within three months of the most recent monitoring. Employees must also be informed of those sampling results in writing within 15 working days after completing the exposure assessment. Whenever an exposure assessment indicates that exposures are above the PEL, the employer shall describe in written notification the corrective action being taken to reduce employee exposures.

After repeat monitoring has taken place (non-initial), and results indicate that employee exposures are now below the action level, the monitoring shall be repeated within six months. This sampling will be repeated until two consecutive measurements, taken seven or more days apart, are consistently below the action level. At that point, monitoring may be discontinued. 

If there is a change in the production, process, exposure control equipment, personnel, or work practices that may be expected to result in new or higher potential exposures, sampling shall be conducted again to verify that exposure to silica is adequately controlled. 

Engineering Controls, Work Practices & Respiratory Protection 

The tables below outline the OSHA-required engineering controls, work practices, and respiratory protection minimum assigned protection factor for workers who are exposed to silica during specific activities. For clarification, NIOSH n95 respirators are appropriate for APF 10 respiratory protection factors. 

• OSHA Action Level - Respirable crystalline silica > 25 µg / m3 of air TWA (over an 8-hour shift). 
• OSHA PEL – Respirable crystalline silica > 50 µg / m3 of air TWA (over an 8-hour shift). 

Engineering controls will be used to limit worker exposure to respirable crystalline silica, provide respirators when engineering controls cannot adequately limit exposure, limit worker access to high exposure areas, develop a written exposure prevention program, offer medical exams to highly exposed workers, and train workers on silica risks and how to limit exposures. 

Medical exams will be provided to monitor workers who are required to wear a respirator for more than 30 days a year as a result of exposure to respirable silica and give them information about their lung health.