What is silica?
Silica is one of the most common naturally occurring elements on the planet. Silica, the mineral compound silicon dioxide (SiO2), is found in two forms -- crystalline or noncrystalline (also referred to as amorphous). Sand and quartz are common examples of crystalline silica.

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When is silica a hazard for construction workers?
Materials that contain crystalline silica are not hazardous unless they are disturbed, generating small-sized particles that can get in your lungs (“respirable crystalline silica”). For example, blasting, cutting, chipping, drilling and grinding materials that contain silica can result in silica dust that is hazardous for construction workers and others to breathe. For a list of construction materials that contain silica go to the “Know the Hazard” section of this website.

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What construction materials contain silica?
Many common construction materials contain silica including, for example, asphalt, brick, cement, concrete, drywall, grout, mortar, stone, sand, and tile. A more complete list of building materials that contain silica, as well as information on how to find out if the material you’re working with contains silica, can be found in Step 1 of the Create-A-Plan section of the website.

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How much silica dust is too much?
It only takes a very small amount of the very fine respirable silica dust to create a health hazard. Recognizing that very small, respirable silica particles are hazardous, OSHA regulation 29 CFR 1926.55(a) requires construction employers to keep worker exposures at or below a Permissible Exposure Level (PEL) of 50 µg/m³. The American Conference of Governmental Industrial Hygienists has a lower non-regulatory Threshold Limit Value of 25 µg/m³. More information about the hazard and links to examples of exposures with and without controls compared to the OSHA PEL, can be found at "Know the Hazard? Why is Silica Hazardous?".

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What illnesses can result from breathing in dust that contains silica?
Inhaling crystalline silica can lead to serious, sometimes fatal illnesses including silicosis, lung cancer, tuberculosis (in those with silicosis), and chronic obstructive pulmonary disease (COPD). In addition, silica exposure has been linked to other illnesses including renal disease and other cancers. In 1996, the World Health Organization – International Agency on Cancer Research (IARC) identified crystalline silica as a “known human carcinogen” (they reaffirmed this position in 2009). The American Thoracic Society and the American College of Occupational and Environmental Medicine have also recognized the adverse health effects of exposure to crystalline silica, including lung cancer.

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What is silicosis?
Silicosis is a disabling, irreversible, and sometimes fatal lung disease. When a worker inhales crystalline silica, the lungs react by developing hard nodules and scarring around the trapped silica particles. If the nodules become too large, breathing becomes difficult and death can result. The risk of silicosis is high for workers in several industries, including the construction industry, according to the Center for Disease Control (CDC), the National Institute for Occupational Safety and Health (NIOSH), and the Occupational Safety and Health Administration (OSHA).

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I don’t know anyone with silicosis so why should I be worried?
Unlike a work-related injury where the effects are seen immediately, silicosis and other silica-related illnesses may not show up for many years after exposure. The most common early symptoms are a chronic dry cough and shortness of breath with physical activity. There are three types of silicosis:
- Chronic silicosis, which usually occurs after 10 or more years of exposure to crystalline silica at relatively low concentrations;
- Accelerated silicosis, which results from exposure to high concentrations of crystalline silica and develops 5 to 10 years after the initial exposure; and
- Acute silicosis, which occurs where exposure concentrations are the highest and can cause symptoms to develop within a few weeks to 4 or 5 years after the initial exposure.
Silicosis is a progressive disease – meaning it continues to get worse, even when exposure to respirable silica has stopped.

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How many people are diagnosed with silicosis each year?
Millions of workers are exposed to dust containing silica. A recent study, Estimating the Total Number of Newly-Recognized Silicosis Cases in the U.S., determined that between 3,600 to 7,300 new cases of silicosis occur annually in the United States. However, only two of the 50 states, New Jersey and Michigan, have surveillance programs to track cases of silicosis. As a result, many cases of silicosis are not reported and many more are not properly diagnosed. One study, Previously Undetected Silicosis in New Jersey Decedents, which reviewed the chest x-rays of individuals exposed to silica dust during their life-time, found evidence of silicosis that had not been diagnosed.

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How should I avoid bringing dust home on my clothes?
The National Institute for Occupational Safety and Health (NIOSH) recommends that workers avoid bringing silica dust home from work by:
- Changing into disposable or washable work clothes at the worksite.
- Showering (if possible) and changing into clean clothes before leaving the worksite to prevent contamination of other work areas, cars, and homes.
- Parking your car where it will not be contaminated with silica.
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What should employers do to protect their employees?
Planning is essential to reducing exposures and protecting workers. Paragraph (g) of the OSHA Standard (§1926.1153 Respirable Crystalline Silica) requires employers to have a “Written exposure control plan” that contains at least the following elements: “(i) A description of the tasks in the workplace that involve exposure to respirable crystalline silica; (ii) A description of the engineering controls, work practices, and respiratory protection used to limit employee exposure to respirable crystalline silica for each task; (iii) A description of the housekeeping measures used to limit employee exposure to respirable crystalline silica; and (iv) A description of the procedures used to restrict access to work areas, when necessary, to minimize the number of employees exposed to respirable crystalline silica and their level of exposure, including exposures generated by other employers or sole proprietors.” The standard also requires employers to “review and evaluate the effectiveness of the written exposure control plan at least annually and update it as necessary”, and designate a “competent person” to implement the plan. Note: The Silica Control Plan generated by using the "Create-A-Plan" tool can also be presented as a toolbox talk.

In addition, paragraph (i)(2) of the standard requires employers to train all employees – workers and supervisors – on the information in the plan, including how to identify a silica hazard, proper use and maintenance of equipment and controls, the importance of using personal protective equipment provided, and the medical surveillance procedures. The "Create-A-Plan" section of this website is a free resource designed to help employers develop their written exposure control plan. The planning tool walks an employer through 3 critical planning steps and generates a silica control plan that can be printed, emailed, or saved. The "Training and Other Resources" section includes silica-related instructional materials, toolbox talks, handouts, videos, and other resources employers can use to train their employees.

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How do I prevent exposures and control the dust?
Prevent the dust from becoming airborne by using engineering controls to reduce exposures. Water can be used to suppress the dust and vacuums can be used to capture it at the source. When water or vacuums are not feasible, or if the exposures are still high even with these controls, a NIOSH approved respirator should be used; however, respirators won’t protect those working close by. Other ways to reduce or eliminate exposures include using different materials, such as aluminum oxide instead of sand for abrasive blasting, or using work practices that help minimize dust. The “Create-A-Plan” tool on this website provides examples by material and task for controlling dust.

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What can I do to protect myself?
It is your employer’s responsibility by law to provide a safe workplace. This is an OSHA requirement. However, it is a worker’s responsibility to use the equipment provided, participate in educational programs on silica, and follow his or her employer’s safety and health instructions. NIOSH recommends that workers:
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Where can I find out about silica related rules and regulations?
OSHA is the primary source for information on the regulation that covers silica exposures and measures employers are required to take to protect their employees. To learn more go to OSHA Silica Standard for Construction.

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Where can I find help in my area on silica?
OSHA offers free and confidential advice to small and medium-sized businesses through an On-site Consultation Program. Consultants from state agencies or universities work with employers to identify workplace hazards, provide advice on compliance with OSHA standards, and assist in establishing safety and health management systems.” To learn more visit OSHA On-Site Consultation

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What is Table 1?
Table 1 is the "specified exposure control method" in the silica standard (Section (c)). It includes pre-defined tasks and specified control methods. An employer that fully implements an equipment-control option on Table 1 for a task will not have to perform air monitoring for that task.

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If my task isn't on Table 1, what do I have to do to comply with the standard?
OSHA requires employers not following Table 1 to do an exposure assessment using the performance option, scheduled monitoring, or a combination:
- Performance or 'Objective Data': includes air monitoring data compiled by the employer or third parties, such as universities, trade associations, or manufacturers, which is sufficient to accurately characterize exposure to prove the control method used reduces silica dust exposure below the permissible exposure level (PEL) of 50 μg/m3 over an 8-hour time weighted average (TWA). The data relied on must reflect conditions that are similar or worse than the employers current worksite conditions.
- Scheduled Air Monitoring: uses air monitoring data to ensure employees are not exposed above the PEL. When this option is used, an employer is required to implement an air monitoring program following the schedule outlined in the standard:
CPWR's Exposure Control Database can help you anticipate and control worker exposures to silica, welding fumes, lead, and noise. This free online tool allows users to enter a construction task, proposed controls, and other variables and obtain a predicted exposure level based on exposure data from trusted sources. A recorded webinar on the database will walk you through its features.

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If my task is listed on Table 1, do I have to follow Table 1?
No. Employers can choose to use the equipment/control options in Table 1 or they can use one of the alternative exposure control methods (performance or objective data, and scheduled air monitoring) to demonstrate compliance. CPWR's Exposure Control Database can help you anticipate and control worker exposures to silica, welding fumes, lead, and noise. This free online tool allows users to enter a construction task, proposed controls, and other variables and obtain a predicted exposure level based on exposure data from trusted sources. A recorded webinar on the database will walk you through its features.

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When do respirators need to be used and what type should be used?
Personal protective equipment, including respirators, should be the last option to prevent a silica exposure. Silica dust should be controlled at the point of origin through the use of vacuum or water controls. However, if using engineering and work practice controls are not enough to reduce the exposure to below the PEL, respirators may be required. Table 1 of the silica standard includes respirator requirements for certain tasks and under certain conditions.

The types of respirators required will depend on the task and degree of protection needed. Any respirator used will fall under OSHA’s respiratory protection standard. Please see OSHA’s respiratory protection requirements for more information on how to comply with the OSHA respiratory protection standard, https://www.osha.gov/SLTC/respiratoryprotection/index.html.

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How do I clean dust on surfaces?
The housekeeping provision in the silica standard requires the use of wet methods, a HEPA vacuum, or another method which effectively minimizes dust exposure. Dry sweeping or dry brushing is NOT allowed unless other methods are not feasible. Using sweeping compounds (e.g., non-grit, oil- or waxed-based) is an acceptable dust suppression housekeeping method.

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What is a competent person under the standard and what are they responsible for?
A “competent person” is defined in OSHA’s silica standard for construction as “an individual who is capable of identifying existing and foreseeable respirable crystalline silica hazards in the workplace and who has the authority to take prompt corrective measures to eliminate or minimize them. The competent person must have the knowledge and ability necessary to fulfill the responsibilities set forth in paragraph (g) of this section.”

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Do I need to provide all of my employees with medical surveillance?
OSHA's silica standard for construction only requires employers to offer a medical examination to workers who will be required to wear a respirator for 30 or more days per year when performing work covered by the standard. Workers that fall into this category must be given the opportunity to have the examination required under the standard within 30 days after the initial assignment of work “unless the employee has received a medical examination that meets the requirements … within the last three years.” If the employee can demonstrate that they have already had an exam within the last three years, the employer does not have to offer another medical exam. A worker can use the copy of the "medical opinion" received from their employer at the time of the exam to demonstrate that they do not need to have another exam.

Page 48 of OSHA's Small Entity Compliance Guide for the Respirable Crystalline Silica Standard for Construction offers further clarification:
1. "Employers must make an initial or periodic medical examination available to employees who will be required by the silica standard to wear a respirator for 30 days or more per year in the upcoming year (365 days). If the employee is required to wear a respirator at any time during a day, that counts as one day of respirator use.
2. An employer will be able to estimate how often respirator use will be required by the standard in the upcoming year based on the types of tasks that the employee will perform, as well as how long and how often those tasks are performed. Respirator use with past employers does not count toward the 30-day threshold.
3. When unexpected circumstances result in employees being required to wear respirators more frequently than first expected, employers must make medical surveillance available as soon as it becomes apparent that the employee will be required by the silica standard to wear a respirator for 30 or more days in the upcoming year."
Additionally, we have created a "Medical Monitoring Under the OSHA Silica Standard for the Construction Industry Guide for Employers." This guide is intended to help employers
1. understand the medical monitoring requirements (paragraph (h)) in the OSHA silica standard for the construction industry (§1926.1153 Respirable Crystalline Silica), and
2. set up the program for their employees.
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What are the training requirements under the standard?
The respirable crystalline silica standard for construction requires that employees covered by the standard be trained on:
- Health hazards associated with respirable crystalline silica exposure.
- The contents of the respirable crystalline silica standard.
- Specific workplace tasks that could expose employees to respirable crystalline silica.
- Specific measures the employer is implementing to protect employees from respirable crystalline silica exposure, including engineering controls, work practices, and respirators to be used.
- The identity of the competent person designated by the employer.
- The purpose and a description of the medical surveillance program required under the standard.
For more information on training, see OSHA's Small Entity Compliance Guide for the Respirable Crystalline Silica Standard for Construction, pages 56-58. For training resources, see our Training and Resources page.

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What type of training is necessary for the competent person?
According to OSHA’s Small Entity Compliance Guide for the Standard for Respirable Crystalline Silica for Construction, page 47:“The standard does not require specific training for a competent person. The employer is responsible for determining what training is necessary to provide the knowledge and ability for his or her competent person to implement the written exposure control plan.
The training will depend on the types of work done, and in some cases, successfully completing training required under the silica standard and OSHA’s Hazard Communication standard will be enough. In other cases, additional training may be needed. For example, a competent person might only need training on controls for power tools that they do not typically use to do their own tasks, so that they could help other employees with questions about or problems with dust controls on those tools. In contrast, a competent person for heavy equipment tasks may require more specialized training in heavy equipment inspection or in recognizing different soil types to determine if exposures might be a concern.”

For recommended skills for competent persons, see the American Industrial Hygiene Association’s (AIHA’s) Recommended Skills and Capabilities for Silica Competent Persons White Paper located on our Training and Resources page.

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When is a written exposure control plan required?
The respirable crystalline silica standard applies to all occupational exposures to respirable crystalline silica in construction work, except where employee exposures will remain below 25 micrograms per cubic meter of air (µg/m3) as an 8-hour time-weighted average (TWA) under any foreseeable conditions.
All employers covered by the standard, including employers who are fully and properly implementing the specified exposure controls in Table 1, must develop and implement a written exposure control plan. Our “Create-A-Plan” tool can be used to develop your written exposure control plan.

The plan serves as documentation and a guide for how silica exposures will be controlled on projects, and employers are required to make the written exposure control plan available for examining or copying to OSHA and NIOSH upon request, as well as employees covered by the standard, and the employees designated representative. Additionally, we encourage employers to share their plan(s) with other contractors on a jobsite.

For more information see OSHA’s Small Entity Compliance Guide for the Standard for Respirable Crystalline Silica for Construction.

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When do I need to perform air monitoring?
Construction employers who fully and properly implement the specified exposure control measures in paragraph (c) of the construction standard (i.e., Table 1) are not required to assess employee exposures.
Employers in general industry and maritime, and construction who do not fully and properly implement the controls in paragraph (c) of the construction standard, can choose between two options for assessing exposures:
- The performance option; or
- The scheduled monitoring option.
The performance option does not include a schedule for conducting exposure assessments. It gives employers flexibility to determine the 8-hour TWA exposure for each employee based on any combination of air monitoring data or objective data that can accurately characterize employee exposures to respirable crystalline silica.

The scheduled monitoring option lets employers know when and how often they must perform air monitoring to measure employee exposures. Under the scheduled monitoring option, how often monitoring must be done depends on the results of initial monitoring and, thereafter, any required further monitoring, as follows:
- If the initial monitoring indicates that employee exposures are below the action level, no further monitoring is required.
- If the most recent exposure monitoring reveals employee exposures at or above the action level but at or below the PEL, the employer must repeat monitoring within six months of the most recent monitoring.
- If the most recent exposure monitoring reveals employee exposures above the PEL, the employer must repeat monitoring within three months of the most recent monitoring.
- When two non-initial monitoring results taken consecutively, at least 7 days apart but within 6 months of each other, are below the action level, employers may stop monitoring for employees represented by those results, as long as no changes occur that could reasonably be expected to result in new or additional exposures at or above the action level.
If an employer is following the scheduled monitoring option, that employer may eventually decide that continued monitoring may not better characterize employee exposure. If that is the case and the air monitoring data continue to accurately characterize employee exposures, employers can use the existing data to meet their exposure assessment obligations under the performance option without conducting additional monitoring.

When following either the performance option or scheduled monitoring option, the employer must reassess exposures whenever a change in production, process, control equipment, personnel, or work practices may reasonably be expected to result in new or additional exposures to respirable crystalline silica at or above the action level, or when the employer has any reason to believe that new or additional exposures at or above the action level have occurred.

See pages 34-37 in OSHA’s Small Entity Compliance Guide for the Standard for Respirable Crystalline Silica for Construction for more information about exposure assessment requirements.

Additionally for more information on how to perform air monitoring, see our page: https://www.silica-safe.org/plan/option-2-perform-air-monitoring.
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How do I wash clothing after working around respirable crystalline silica?
Clothing that has been contaminated with silica dust should be washed separately from other clothing after each shift. See NIOSH’s infographic on reducing dust exposure from work clothes: https://www.cdc.gov/niosh/mining/UserFiles/works/pdfs/WorkClothes_DustExposureInfographics_508.pdf. For more information see NIOSH’s Instructional Materials on the Clothes Cleaning Process

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If I use a vacuum to control the dust, how should I dispose of the dust collected in the filter and vacuum to prevent exposures to respirable crystalline silica?
Vacuum manufacturers operator’s manuals typically provide instructions for changing dust bags and filters. For example, this could involve disposing of dust bags and filters in sealed, impermeable containers such as heavy-gauge plastic bags to prevent the release of dust particles into the air.
Additionally, NIOSH’s Mining Division has found that folding bulk or mini-bag loading collars away from you can reduce the potential for respirable dust exposure. See their infographic: https://www.cdc.gov/niosh/mining/UserFiles/works/pdfs/TyingBags_DustExposureInfographics_508.pdf.

Some states may have specific requirements for disposing of construction waste, including dust containing silica. Contact your state Department of Environmental Protection or your regional office of the Federal Environmental Protection Agency (EPA) for more information.
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How do I properly dispose of slurry after using wet methods to prevent exposures to respirable crystalline silica?
According to OSHA’s Small Entity Compliance Guide for the Standard for Respirable Crystalline Silica for Construction, page 43:
“Slurry generated by wet methods should be cleaned up before it dries using a wet vacuum. When emptying the vacuum, the slurry will be transferred into a plastic bag and placed inside a container for disposal. The container will be sealed to prevent the release of dust back into the work space.

Never sweep or used compressed air on dried slurry, if slurry dries, immediately wet it down and clean it up with the wet vacuum. “

Additionally, some states may have specific requirements for disposing of construction waste, including dust containing silica. Contact your state Department of Environmental Protection or your regional office of the Federal Environmental Protection Agency (EPA) for more information.
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Frequently Asked Questions

For OSHA's Frequently Asked Questions for the Construction Industry, see FAQs for the Construction Industry and the Spanish translation, preguntas frecuentes en la industria de la construcción.

For OSHA's Frequently Asked Questions for General Industry, see FAQs for General Industry.

CPWR's Preguntas frecuentes (Frequently Asked Questions - Spanish)

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