OSHA construction silica study guide
OSHA's construction silica standard (29 CFR 1926.1153) covers occupational exposure to respirable crystalline silica in construction work. This guide sets out what the rule text states on its scope and definitions, the Table 1 specified exposure control methods, the alternative exposure control methods (PEL, action level and exposure assessment), respiratory protection, housekeeping, the written exposure control plan and competent person, medical surveillance, hazard communication and training, and recordkeeping. Every point links to the regulation and quotes its exact words.
Scope and definitions
1926.1153 applies to all occupational exposures to respirable crystalline silica in construction work, except where employee exposure will remain below 25 micrograms per cubic meter of air (25 µg/m3) as an 8-hour time-weighted average under any foreseeable conditions.
“This section applies to all occupational exposures to respirable crystalline silica in construction work, except where employee exposure will remain below 25 micrograms per cubic meter of air (25 µg/m3) as an 8-hour time-weighted average (TWA) under any foreseeable conditions.”
The action level is an airborne respirable crystalline silica concentration of 25 µg/m3, calculated as an 8-hour TWA.
“Action level means a concentration of airborne respirable crystalline silica of 25 µg/m3, calculated as an 8-hour TWA.”
Respirable crystalline silica means quartz, cristobalite and/or tridymite in airborne particles that are determined to be respirable by a sampling device designed to meet the respirable-particle-size-selective sampler characteristics in ISO 7708:1995.
“Respirable crystalline silica means 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”
Employee exposure is the exposure to airborne respirable crystalline silica that would occur if the employee were not using a respirator.
“Employee exposure means the exposure to airborne respirable crystalline silica that would occur if the employee were not using a respirator.”
A competent person can identify existing and foreseeable silica hazards and is authorized to take prompt corrective measures to eliminate or minimize them, with the knowledge and ability to carry out the duties in paragraph (g).
“Competent person means an individual who is capable of identifying existing and foreseeable respirable crystalline silica hazards in the workplace and who has authorization 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.”
A HEPA filter is at least 99.97 percent efficient in removing mono-dispersed particles of 0.3 micrometers in diameter.
“High-efficiency particulate air [HEPA] filter means a filter that is at least 99.97 percent efficient in removing mono-dispersed particles of 0.3 micrometers in diameter.”
Specified exposure control methods (Table 1)
For each employee doing a task listed on Table 1, the employer must fully and properly implement the engineering controls, work practices and respiratory protection that Table 1 specifies for that task, unless it assesses and limits exposure under paragraph (d).
“For each employee engaged in a task identified on Table 1, the employer shall fully and properly implement the engineering controls, work practices, and respiratory protection specified for the task on Table 1, unless the employer assesses and limits the exposure of the employee to respirable crystalline silica in accordance with paragraph (d) of this section.”
Table 1's last column gives the required respiratory protection and minimum assigned protection factor (APF) separately for four hours or less per shift (≤4) and for more than four hours per shift (>4).
“Required respiratory protection and minimum assigned protection factor (APF) ≤4 >4 hours/ hours/ shift shift”
When implementing the Table 1 control measures, for tasks done indoors or in enclosed areas the employer must provide a means of exhaust as needed to minimize the accumulation of visible airborne dust.
“For tasks performed indoors or in enclosed areas, provide a means of exhaust as needed to minimize the accumulation of visible airborne dust;”
When a Table 1 measure includes an enclosed cab or booth, the employer must ensure it is kept as free as practicable from settled dust, has working door seals, closing mechanisms, gaskets and seals, is under positive pressure through continuous delivery of fresh air, has intake air filtered through a filter 95% efficient in the 0.3-10.0 µm range (e.g., MERV-16 or better), and has heating and cooling capabilities.
“For measures implemented that include an enclosed cab or booth, ensure that the enclosed cab or booth: (A) Is maintained as free as practicable from settled dust; (B) Has door seals and closing mechanisms that work properly; (C) Has gaskets and seals that are in good condition and working properly; (D) Is under positive pressure maintained through continuous delivery of fresh air; (E) Has intake air that is filtered through a filter that is 95% efficient in the 0.3-10.0 µm range (e.g., MERV-16 or better); and (F) Has heating and cooling capabilities.”
If an employee does more than one Table 1 task in a shift and all tasks combined last more than four hours, each task requires the respiratory protection listed for more than four hours per shift; if the total is less than four hours, the less-than-four-hours protection applies.
“Where an employee performs more than one task on Table 1 during the course of a shift, and the total duration of all tasks combined is more than four hours, the required respiratory protection for each task is the respiratory protection specified for more than four hours per shift. If the total duration of all tasks on Table 1 combined is less than four hours, the required respiratory protection for each task is the respiratory protection specified for less than four hours per shift.”
Stationary masonry saws: use a saw with an integrated water delivery system that continuously feeds water to the blade, and operate and maintain the tool according to the manufacturer's instructions to minimize dust emissions; Table 1 lists no respirator (None) for either duration.
“(i) Stationary masonry saws Use saw equipped with integrated water delivery system that continuously feeds water to the blade None None. Operate and maintain tool in accordance with manufacturer's instructions to minimize dust emissions”
Handheld power saws (any blade diameter) with integrated water delivery: outdoors, no respirator for four hours or less and APF 10 for more than four hours; indoors or in an enclosed area, APF 10 for both.
“—When used outdoors None APF 10. —When used indoors or in an enclosed area APF 10 APF 10.”
Handheld and stand-mounted drills (including impact and rotary hammer drills): use a drill with a commercially available shroud or cowling with dust collection system, operate and maintain it per the manufacturer's instructions, use a dust collector that provides the tool maker's recommended air flow or greater and has a filter with 99% or greater efficiency and a filter-cleaning mechanism, and use a HEPA-filtered vacuum when cleaning holes.
“Use drill equipped with commercially available shroud or cowling with dust collection system Operate and maintain tool in accordance with manufacturer's instructions to minimize dust emissions 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”
Jackhammers and handheld powered chipping tools, one Table 1 option: a tool with a water delivery system that supplies a continuous stream or spray of water at the point of impact; outdoors, no respirator for four hours or less and APF 10 for more than four hours; indoors or in an enclosed area, APF 10 for both.
“Use tool with water delivery system that supplies a continuous stream or spray of water at the point of impact: —When used outdoors None APF 10. —When used indoors or in an enclosed area APF 10 APF 10.”
Handheld grinders for mortar removal (tuckpointing): use a grinder with a commercially available shroud and dust collection system; Table 1 lists APF 10 for four hours or less and APF 25 for more than four hours per shift.
“Use grinder equipped with commercially available shroud and dust collection system APF 10 APF 25.”
The same tuckpointing row also requires operating and maintaining the tool according to the manufacturer's instructions, and a dust collector that provides 25 cfm or more of airflow per inch of wheel diameter with a filter of 99% or greater efficiency and a cyclonic pre-separator or filter-cleaning mechanism.
“Operate and maintain tool in accordance with manufacturer's instructions to minimize dust emissions 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”
Not covered here
The full row-by-row content of Table 1 is not repeated here; only a few rows are summarized. Check the table itself for the exact controls and respirator columns for each tool. We only write what an official source states, so study these parts with your certifying program's materials.
Alternative exposure control methods
The alternative exposure control methods in paragraph (d) apply to tasks not listed in Table 1, or where the employer does not fully and properly implement the Table 1 controls.
“Alternative exposure control methods. For tasks not listed in Table 1, or where the employer does not fully and properly implement the engineering controls, work practices, and respiratory protection described in Table 1:”
Under paragraph (d), no employee may be exposed to respirable crystalline silica in excess of 50 µg/m3, calculated as an 8-hour TWA (the PEL).
“The employer shall ensure that no employee is exposed to an airborne concentration of respirable crystalline silica in excess of 50 µg/m3, calculated as an 8-hour TWA.”
The employer must assess the exposure of each employee who is or may reasonably be expected to be exposed at or above the action level, using either the performance option or the scheduled monitoring option.
“The employer shall assess the exposure of each employee who is or may reasonably be expected to be exposed to respirable crystalline silica at or above the action level in accordance with either the performance option in paragraph (d)(2)(ii) or the scheduled monitoring option in paragraph (d)(2)(iii) of this section.”
Performance option: the 8-hour TWA exposure for each employee is assessed from any combination of air monitoring data or objective data sufficient to accurately characterize exposures.
“The employer shall assess the 8-hour TWA exposure for each employee on the basis of any combination of air monitoring data or objective data sufficient to accurately characterize employee exposures to respirable crystalline silica.”
Scheduled monitoring option: initial monitoring uses one or more personal breathing zone air samples that reflect exposures on each shift, for each job classification, in each work area.
“The employer shall perform initial monitoring to assess the 8-hour TWA exposure for each employee on the basis of one or more personal breathing zone air samples that reflect the exposures of employees on each shift, for each job classification, in each work area.”
Under the scheduled monitoring option, if the most recent monitoring shows exposures at or above the action level but at or below the PEL, monitoring must be repeated within six months of the most recent monitoring.
“Where the most recent exposure monitoring indicates that employee exposures are at or above the action level but at or below the PEL, the employer shall repeat such monitoring within six months of the most recent monitoring.”
Under the scheduled monitoring option, if the most recent monitoring shows exposures above the PEL, monitoring must be repeated within three months of the most recent monitoring.
“Where the most recent exposure monitoring indicates that employee exposures are above the PEL, the employer shall repeat such monitoring within three months of the most recent monitoring.”
Under the scheduled monitoring option, if the most recent non-initial monitoring is below the action level, monitoring is repeated within six months until two consecutive measurements, taken seven or more days apart, are below the action level; then it may stop for the represented employees, except as the reassessment paragraph (d)(2)(iv) provides.
“Where the most recent (non-initial) exposure monitoring indicates that employee exposures are below the action level, the employer shall repeat such monitoring within six months of the most recent monitoring until two consecutive measurements, taken seven or more days apart, are below the action level, at which time the employer may discontinue monitoring for those employees whose exposures are represented by such monitoring, except as otherwise provided in paragraph (d)(2)(iv) of this section.”
Exposures must be reassessed whenever a change in production, process, control equipment, personnel or work practices may reasonably be expected to cause new or additional exposures at or above the action level, or when the employer has any reason to believe such exposures have occurred.
“The employer shall reassess exposures whenever a change in the production, process, control equipment, personnel, or work practices may reasonably be expected to result in new or additional exposures 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.”
Within five working days after completing an exposure assessment, the employer must individually notify each affected employee of the results in writing, or post the results in an appropriate location accessible to all affected employees.
“Within five working days after completing an exposure assessment in accordance with paragraph (d)(2) of this section, the employer shall individually notify each affected employee in writing of the results of that assessment or post the results in an appropriate location accessible to all affected employees.”
When an assessment shows exposure above the PEL, the written notification must describe the corrective action being taken to reduce exposure to or below the PEL.
“Whenever an exposure assessment indicates that employee exposure is above the PEL, the employer shall describe in the written notification the corrective action being taken to reduce employee exposure to or below the PEL.”
Methods of compliance and respiratory protection
Under paragraph (d), engineering and work practice controls must be used to keep exposure at or below the PEL unless the employer can show they are not feasible; if feasible controls are not enough, they must still be used to reach the lowest feasible level and be supplemented with respirators.
“The employer shall use engineering and work practice controls to reduce and maintain employee exposure to respirable crystalline silica to or below the PEL, unless the employer can demonstrate that such controls are not feasible. Wherever such feasible engineering and work practice controls are not sufficient to reduce employee exposure to or below the PEL, the employer shall nonetheless use them to reduce employee exposure to the lowest feasible level and shall supplement them with the use of respiratory protection that complies with the requirements of paragraph (e) of this section.”
Where respiratory protection is required, the employer must provide each employee an appropriate respirator that complies with paragraph (e) and 29 CFR 1910.134.
“Where respiratory protection is required by this section, the employer must provide each employee an appropriate respirator that complies with the requirements of this paragraph and 29 CFR 1910.134.”
For tasks not listed in Table 1 (or where Table 1 is not fully and properly implemented), respirators are required where exposures exceed the PEL while feasible controls are being installed or implemented, where exposures exceed the PEL during tasks (such as certain maintenance and repair tasks) for which controls are not feasible, and during tasks where all feasible controls are not sufficient to reach the PEL.
“(A) Where exposures exceed the PEL during periods necessary to install or implement feasible engineering and work practice controls; (B) Where exposures exceed the PEL during tasks, such as certain maintenance and repair tasks, for which engineering and work practice controls are not feasible; and (C) During tasks for which an employer has implemented all feasible engineering and work practice controls and such controls are not sufficient to reduce exposures to or below the PEL.”
An employer that fully and properly implements Table 1 for a listed task is considered in compliance with paragraph (e)(1) and with the respirator selection requirements of 1910.134(d)(1)(iii) and (d)(3) for silica.
“if the employer fully and properly implements the engineering controls, work practices, and respiratory protection described in Table 1, the employer shall be considered to be in compliance with paragraph (e)(1) of this section and the requirements for selection of respirators in 29 CFR 1910.134(d)(1)(iii) and (d)(3) with regard to exposure to respirable crystalline silica.”
Not covered here
The details of the respiratory protection program, respirator selection and fit testing in 29 CFR 1910.134, which 1926.1153 refers to but does not repeat. We only write what an official source states, so study these parts with your certifying program's materials.
Housekeeping and written plan
Dry sweeping or dry brushing is not allowed where it could contribute to silica exposure, unless wet sweeping, HEPA-filtered vacuuming or other methods that minimize exposure are not feasible.
“The employer shall not allow dry sweeping or dry brushing where such activity could contribute to employee exposure to respirable crystalline silica unless wet sweeping, HEPA-filtered vacuuming or other methods that minimize the likelihood of exposure are not feasible.”
Compressed air may not be used to clean clothing or surfaces where it could contribute to exposure, unless it is used with a ventilation system that effectively captures the dust cloud, or no alternative method is feasible.
“The employer shall not allow compressed air to be used to clean clothing or surfaces where such activity could contribute to employee exposure to respirable crystalline silica unless: (i) The compressed air is used in conjunction with a ventilation system that effectively captures the dust cloud created by the compressed air; or (ii) No alternative method is feasible.”
The written exposure control plan must describe the tasks involving silica exposure and the engineering controls, work practices and respiratory protection used for each task.
“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;”
The plan must also describe the housekeeping measures used, and the procedures used to restrict access to work areas when necessary to minimize the number of employees exposed and their level of exposure, including exposures generated by other employers or sole proprietors.
“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 employer must review and evaluate the plan's effectiveness at least annually and update it as necessary.
“The employer shall review and evaluate the effectiveness of the written exposure control plan at least annually and update it as necessary.”
The plan must be readily available for examination and copying, upon request, to each covered employee, their designated representatives, the Assistant Secretary and the Director.
“The employer shall make the written exposure control plan readily available for examination and copying, upon request, to each employee covered by this section, their designated representatives, the Assistant Secretary and the Director.”
The employer must designate a competent person to make frequent and regular inspections of job sites, materials and equipment to implement the written plan.
“The employer shall designate a competent person to make frequent and regular inspections of job sites, materials, and equipment to implement the written exposure control plan.”
Medical surveillance
Medical surveillance must be available at no cost, at a reasonable time and place, for each employee who will be required under the section to use a respirator for 30 or more days per year.
“The employer shall make medical surveillance available at no cost to the employee, and at a reasonable time and place, for each employee who will be required under this section to use a respirator for 30 or more days per year.”
An initial (baseline) examination must be offered within 30 days after initial assignment, unless the employee had an exam meeting the section's requirements within the last three years.
“The employer shall make available an initial (baseline) medical examination within 30 days after initial assignment, unless the employee has received a medical examination that meets the requirements of this section within the last three years.”
The initial examination includes a physical examination with special emphasis on the respiratory system and a chest X-ray interpreted and classified according to the ILO International Classification of Radiographs of Pneumoconioses by a NIOSH-certified B Reader.
“A physical examination with special emphasis on the respiratory system; (iii) A chest X-ray (a single posteroanterior radiographic projection or radiograph of the chest at full inspiration recorded on either film (no less than 14 x 17 inches and no more than 16 x 17 inches) or digital radiography systems), interpreted and classified according to the International Labour Office (ILO) International Classification of Radiographs of Pneumoconioses by a NIOSH-certified B Reader;”
The initial examination also includes a pulmonary function test (FVC, FEV1 and FEV1/FVC ratio) given by a spirometry technician with a current certificate from a NIOSH-approved spirometry course, testing for latent tuberculosis infection, and any other tests deemed appropriate by the PLHCP.
“A pulmonary function test to include forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) and FEV1/FVC ratio, administered by a spirometry technician with a current certificate from a NIOSH-approved spirometry course; (v) Testing for latent tuberculosis infection; and (vi) Any other tests deemed appropriate by the PLHCP.”
Periodic exams (the initial exam procedures except tuberculosis testing) must be offered at least every three years, or more often if the PLHCP recommends.
“The employer shall make available medical examinations that include the procedures described in paragraph (h)(2) of this section (except paragraph (h)(2)(v)) at least every three years, or more frequently if recommended by the PLHCP.”
The PLHCP must explain the results to the employee and give the employee a written medical report within 30 days of each exam.
“The employer shall ensure that the PLHCP explains to the employee the results of the medical examination and provides each employee with a written medical report within 30 days of each medical examination performed.”
The employer must obtain a written medical opinion from the PLHCP within 30 days of the exam. It contains only the exam date, a statement that the exam met the section's requirements, and any recommended limitations on the employee's use of respirators, unless the employee gives written authorization: then it also contains either or both of any recommended limitations on silica exposure and a statement that the employee should be examined by a specialist.
“The employer shall obtain a written medical opinion from the PLHCP within 30 days of the medical examination. The written opinion shall contain only the following: (A) The date of the examination; (B) A statement that the examination has met the requirements of this section; and (C) Any recommended limitations on the employee's use of respirators. (ii) If the employee provides written authorization, the written opinion shall also contain either or both of the following: (A) Any recommended limitations on the employee's exposure to respirable crystalline silica; (B) A statement that the employee should be examined by a specialist”
The PLHCP's written medical report for the employee must include a statement that the employee should be examined by a specialist if the chest X-ray is classified as 1/0 or higher by the B Reader, or if the PLHCP otherwise deems referral to a specialist appropriate.
“(iv) A statement that the employee should be examined by a specialist (pursuant to paragraph (h)(7) of this section) if the chest X-ray provided in accordance with this section is classified as 1/0 or higher by the B Reader, or if referral to a specialist is otherwise deemed appropriate by the PLHCP.”
If the PLHCP's written opinion says the employee should see a specialist, the employer must make that exam available within 30 days after receiving the opinion.
“If the PLHCP's written medical opinion indicates that an employee should be examined by a specialist, the employer shall make available a medical examination by a specialist within 30 days after receiving the PLHCP's written opinion.”
Not covered here
Appendix B (Medical Surveillance Guidelines) is for informational and guidance purposes only and is not summarized here. We only write what an official source states, so study these parts with your certifying program's materials.
Communication of hazards, training and records
Respirable crystalline silica must be included in the employer's hazard communication program under 29 CFR 1910.1200; each employee must have access to labels on containers of crystalline silica and safety data sheets and be trained, and the program must address at least cancer, lung effects, immune system effects and kidney effects.
“The employer shall include respirable crystalline silica in the program established to comply with the hazard communication standard (HCS) (29 CFR 1910.1200). The employer shall ensure that each employee has access to labels on containers of crystalline silica and safety data sheets, and is trained in accordance with the provisions of HCS and paragraph (i)(2) of this section. The employer shall ensure that at least the following hazards are addressed: Cancer, lung effects, immune system effects, and kidney effects.”
Each covered employee must be able to demonstrate knowledge and understanding of at least the health hazards, the specific tasks that could cause exposure, and the specific protective measures the employer has implemented, including engineering controls, work practices and respirators to be used.
“(A) The health hazards associated with exposure to respirable crystalline silica; (B) Specific tasks in the workplace that could result in exposure to respirable crystalline silica; (C) Specific measures the employer has implemented to protect employees from exposure to respirable crystalline silica, including engineering controls, work practices, and respirators to be used;”
Each covered employee must also be able to demonstrate knowledge and understanding of the contents of the section, the identity of the designated competent person, and the purpose and a description of the medical surveillance program.
“(D) The contents of this section; (E) The identity of the competent person designated by the employer in accordance with paragraph (g)(4) of this section; and (F) The purpose and a description of the medical surveillance program required by paragraph (h) of this section.”
A copy of 1926.1153 must be readily available without cost to each covered employee.
“The employer shall make a copy of this section readily available without cost to each employee covered by this section.”
The air monitoring record must include at least the date of measurement for each sample, the task monitored, sampling and analytical methods, the number, duration and results of samples, the laboratory that did the analysis, the type of PPE (such as respirators) worn, and the name and job classification of all employees represented, indicating who was actually monitored.
“This record shall include at least the following information: (A) The date of measurement for each sample taken; (B) The task monitored; (C) Sampling and analytical methods used; (D) Number, duration, and results of samples taken; (E) Identity of the laboratory that performed the analysis; (F) Type of personal protective equipment, such as respirators, worn by the employees monitored; and (G) Name and job classification of all employees represented by the monitoring, indicating which employees were actually monitored.”
A medical surveillance record must be kept for each employee covered by medical surveillance under paragraph (h), with the employee's name, copies of the PLHCPs' and specialists' written medical opinions, and a copy of the information given to them.
“(A) Name; (B) A copy of the PLHCPs' and specialists' written medical opinions; and (C) A copy of the information provided to the PLHCPs and specialists.”
Medical surveillance records must be maintained and made available in accordance with 29 CFR 1910.1020.
“The employer shall ensure that medical records are maintained and made available in accordance with 29 CFR 1910.1020.”
The section became effective June 23, 2016; its obligations commenced June 23, 2017, except the sample analysis methods requirement, which commenced June 23, 2018.
“This section shall become effective June 23, 2016. (2) All obligations of this section, except requirements for methods of sample analysis in paragraph (d)(2)(v), shall commence June 23, 2017. (3) Requirements for methods of sample analysis in paragraph (d)(2)(v) of this section commence June 23, 2018.”
Not covered here
The general requirements of the hazard communication standard (29 CFR 1910.1200) and of 29 CFR 1910.1020 on access to exposure and medical records. We only write what an official source states, so study these parts with your certifying program's materials.
Sources
- eCFR: 29 CFR 1926.1153, Respirable crystalline silica (as of Nov 3, 2026)Checked November 5, 2026
Other OSHA Construction study guides: Introduction to OSHA, Fall protection, Scaffolds, Stairways and ladders, Electrical safety, Excavations, Personal protective equipment, Health hazards, Hazard communication, Welding and cutting, General safety and health