Silica Exposure Awareness for Occupational Safety

crystalline silica quartz

What is Silica?

Silica, also known as silicon dioxide (SiO₂), is a naturally occurring mineral in the earth’s crust; often found as stone and sand. Silica occurs in two forms – crystalline silica and amorphous (non-crystalline) silica. Crystalline silica is hard, with a high melting point, and is chemically inactive. Quartz is the most common form of crystalline silica found and used in the creation of various products. Cristobalite and Tridymite are the other two known forms of crystalline silica.

Silica is found in a variety of products, and there are various uses for silica, globally. Crystalline silica is used to make pottery, ceramic, and glass products. Also, when sand, stone, or rocks are used to produce other materials; for example, concrete, mortar, bricks, etc., these transformed products also contain silica. Crystalline silica is also found in granite and paints. Amorphous silica on the other hand is often found in the form of silica gel, and is used in food additives, food wrappings, toothpaste, and cosmetics; as this form of silica has been found to have no adverse health effects at levels found naturally in the environment or commercial products.

What is Respirable Crystalline Silica?

Respirable Crystalline Silica is the tiny airborne particles formed when crystalline silica or any silica-containing materials including rocks, stones, concrete, brick, block, and mortar is manipulated by cutting, drilling, sawing, grinding, crushing, or breaking. This dust is deemed to be 100 times smaller than sand grains found on a beach; and is often referred to as ‘silica dust’. Silica dust can easily be inhaled and get into the human respiratory tract causing harm to the health of those exposed to respirable crystalline silica while working with silica-containing materials.

Silica and the Construction Industry

Workers in the construction industry are the most exposed to respirable crystalline silica as they participate in work activities that require them to cut, saw, grind, and drill silica-containing materials. Such work activities include mixing concrete and mortar, cutting bricks and blocks, abrasive blasting with sand, crushing and grinding stones or rocks, sanding or drilling into concrete walls, cutting granite, etc. Also subjected to the hazards of silica exposure are the employees of brick, concrete block, and stone or granite countertop manufacturers. Furthermore, people working in excavation and trenching operations are also exposed to respirable crystalline silica due to work activities such as sifting sand; and crushing, grinding, and moving rocks that may disturb silica particles.

silica dust from crushing stone

OSHA’s Respirable Crystalline Silica Standard for the Construction Industry

As such, all construction industry workers must obtain adequate knowledge about working with silica and the dangers of silica exposure. Accordingly, the Occupational Safety and Health Administration (OSHA) has developed and implemented the respirable crystalline silica standard for the construction industry (29 CFR 1926.1153) to support employers in their endeavors to protect employees from silica hazards and limit worker exposures to respirable crystalline silica by adopting the appropriate methods and safeguards.

OSHA’s construction industry respirable crystalline silica standard provides flexibility to employers on the different protection methods – specified exposure control methods based on the Silica Table 1 provided in the standard or alternative exposure control methods based on distinct workplace measurements of worker exposure to silica dust and the best ways to limit the permissible exposure limit (PEL) in the workplace by using the  Hierarchy of Controls.

OSHA’s respirable crystalline silica standard for the construction industry specifically requires employers to:

  • Create and implement a written silica exposure control plan. This plan should identify the silica exposure tasks and detail the methods used to protect workers from silica exposure. The plan must also explain the procedures to restrict access to work areas where high exposures may occur.
  • Ensure a competent person is responsible for implementing the written exposure control plan.
  • Identify and use reasonable appropriate alternative housekeeping practices to avoid housekeeping practices that could increase workers’ exposure to silica.
  • Ensure workers who are required by the standard to wear a respirator for 30 days or more annually, undergo medical exams every three years. These medical surveillances examinations should include chest X-rays and lung function tests.
  • Provide workers with the appropriate training on work operations that result in silica exposure and ways to limit exposure.
  • Maintain records of exposure measurements, the relevant objective data, and medical examination records of workers as required.

Silica Used in Other Industries

Silica exposure and awareness are not limited to construction industry workers. Employees in other industries working with silica-containing materials are also in danger of exposure to crystalline silica and silica dust. Popular examples include hydraulic fracturing (fracking) operations and foundry work that requires workers to use sand. Moreover, makers of pottery, ceramic, and glass products are also exposed to silica dust. Therefore, employees exposed to silica in other industries must also be provided with adequate information on silica exposure and gain the appropriate silica awareness training.

These industries, too, are governed by OSHA. OSHA has developed and issued respirable crystalline silica standards for the general industry and maritime (29 CFR 1910.1053) that employers can use to put in place the necessary precautions to reduce silica exposure levels of employees.

Silica Exposure Risks and Controls

Exposure to respirable crystalline silica can result in several health hazards. These illnesses include silicosis, lung cancer, Chronic Obstructive Pulmonary Disease (COPD), kidney disease, activation of latent tuberculosis infections, and autoimmune diseases. Thus, employers must provide the necessary precautions in the workplace to reduce employees’ exposure to silica by implementing a range of appropriate measures as recommended by the OSHA standards. The measures may include a combination of engineering and work practice controls, housekeeping procedures, respiratory protection, medical surveillance, hazard communication, silica air monitoring measures, and silica methods of sample analysis.

Silica Awareness Training

An effective way to create awareness of silica exposure and related silica health hazards in the workplace is to provide relevant training to employees. Our silica awareness online training course will enable employers to fulfill the training requirements as outlined in the Federal OSHA Regulations 29 CFR 1910.1053 and 29 CFR 1926.1153. Our training program aims to acquaint workers with the hazards associated with exposure to respirable crystalline silica and the hazard control measures that must be implemented to minimize exposure within safe limits to comply with the relevant OSHA respirable crystalline silica standards.

So, enroll today, and learn more about the regulatory requirements of working with crystalline silica-containing materials and the exposure control methods that must be implemented in the worksite to ensure compliance and safeguard the health of workers.



SafeSilica. (n.d.). Crystalline Silica: The Science. Website. https://safesilica.eu/crystalline-silica-the-science/

OSHA. (n.d.). Silica, Crystalline. Website.  https://www.osha.gov/silica-crystalline

OSHA. (n.d.). Construction. Complying with the construction standard. Website https://www.osha.gov/silica-crystalline/construction


Published on: November 15, 2021