What Does OSHA's Silica Rule Require on a Job?

By Wyatt Cooper · Published October 22, 2026 · 8 min read

Key takeaways

29 CFR 1926.1153 applies to construction work that exposes workers to respirable crystalline silica, unless exposure will stay below 25 micrograms per cubic meter as an 8-hour average under any foreseeable conditions.
For a task on Table 1, fully following the table's engineering controls, work practices and respirator column is compliance; otherwise the employer must keep exposure at or below 50 µg/m³ and assess it.
Table 1's respirator depends on where and how long: if all of a worker's Table 1 tasks in a shift add up to more than four hours, every task uses the more-than-four-hours column.
Every covered employer also keeps a written exposure control plan, names a competent person, limits dry sweeping and compressed air, trains workers and offers medical exams to those the rule requires to wear a respirator 30 or more days a year.

OSHA's silica rule for construction (29 CFR 1926.1153) gives each employer two ways to comply: follow Table 1's controls and respirators for each listed task, or keep exposure at or below 50 micrograms per cubic meter over 8 hours and measure it. Either way, the employer keeps a written exposure control plan, names a competent person, limits dry sweeping, trains workers and offers medical exams to workers the rule requires to wear a respirator 30 or more days a year.

Who the rule covers, and the two ways to comply

The rule "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" (29 CFR 1926.1153(a)). Cutting, drilling, grinding and breaking concrete, masonry, stone and similar materials are where it bites.

Table 1 (paragraph (c)). For each employee on a listed task, the employer "shall fully and properly implement the engineering controls, work practices, and respiratory protection specified for the task on Table 1". Doing so counts as compliance with the respirator requirements for that task (paragraph (e)(3)).
Alternative methods (paragraph (d)). For a task not on Table 1, or where the table isn't fully followed, no employee may be exposed above 50 µg/m³ as an 8-hour TWA, and the employer assesses exposure at or above the 25 µg/m³ action level by air monitoring or objective data.

Table 1, task by task

Selected rows of Table 1 in 29 CFR 1926.1153, summarized; APF is the respirator's minimum assigned protection factor. Read the full row before relying on it.
Equipment or task	Controls Table 1 specifies	Respirator, 4 hours or less per shift	Respirator, more than 4 hours
(i) Stationary masonry saws	Integrated water delivery to the blade; run to the manufacturer's instructions	None	None
(ii) Handheld power saws, outdoors	Integrated water delivery to the blade	None	APF 10
(ii) Handheld power saws, indoors or enclosed	Integrated water delivery to the blade	APF 10	APF 10
(iii) Handheld saws for fiber-cement board, 8-inch blade or less	Outdoors only: dust collection at the manufacturer's air flow, 99% filter	None	None
(iv) Walk-behind saws, outdoors	Integrated water delivery to the blade	None	None
(iv) Walk-behind saws, indoors or enclosed	Integrated water delivery to the blade	APF 10	APF 10
(vi) Rig-mounted core saws or drills	Integrated water delivery to the cutting surface	None	None
(vii) Handheld and stand-mounted drills	Shroud or cowling with dust collection, 99% filter with filter cleaning; HEPA vacuum to clean holes	None	None
(x) Jackhammers and chipping tools, outdoors	Continuous water at the point of impact, or shroud with dust collection	None	APF 10
(x) Jackhammers and chipping tools, indoors or enclosed	Continuous water at the point of impact, or shroud with dust collection	APF 10	APF 10
(xi) Grinders for mortar removal (tuckpointing)	Shroud with dust collection, 25 cfm per inch of wheel, 99% filter	APF 10	APF 25
(xii) Grinders for other uses, with shroud, indoors or enclosed	Shroud with dust collection, 25 cfm per inch of wheel, 99% filter	None	APF 10
(xviii) Heavy equipment grading or excavating	Water or dust suppressants as needed, or an enclosed cab when the operator is the only one on the task	None	None

Table 1 also has general duties (paragraph (c)(2)): indoors or in an enclosed area, provide exhaust as needed to minimize visible airborne dust; anywhere, wet methods must use enough water to minimize visible dust, and an enclosed cab or booth must be kept clean, sealed, under positive pressure with filtered fresh air, and heated and cooled. Wherever the rule requires a respirator, the employer must also run a respiratory protection program under 29 CFR 1910.134 (paragraph (e)(2)).

The four-hour rule

Paragraph (c)(3): "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." Total the Table 1 time per worker, per shift, before choosing the column.

What every covered employer does, either way

A written exposure control plan describing the tasks with exposure, the controls and respirators for each, the housekeeping, and how access is restricted, "including exposures generated by other employers or sole proprietors"; reviewed at least once a year (paragraph (g)).
A competent person to "make frequent and regular inspections of job sites, materials, and equipment to implement the written exposure control plan" (paragraph (g)(4)).
No dry sweeping or dry brushing where it adds exposure, unless wet sweeping, HEPA vacuuming or other methods aren't feasible; no compressed air for cleaning unless captured by ventilation or there's no alternative (paragraph (f)).
Medical surveillance at no cost for each employee required to wear a respirator under the rule for 30 or more days a year: an initial exam within 30 days of assignment unless the worker had a qualifying exam in the last three years, then at least every three years (paragraph (h)).
Training each covered employee can show they understand, including the hazards, their tasks, the controls, the rule and who the competent person is (paragraph (i)).
Records of air monitoring, objective data relied on, and medical surveillance (paragraph (j)).

OSHA's construction page says employers "can either use the control methods laid out in Table 1 of the construction standard, or they can measure workers' exposure to silica and independently decide which dust controls work best" (OSHA, Silica in Construction).

A worked example: one concrete crew's day

Laborer A — Table 1 tasks and the respirator each needs

Day 1 tasks: Handheld saw with water, outdoors, 2.5 hours; jackhammer with water, indoors, 2 hours
Day 1 total: 2.5 + 2 = 4.5 hours of Table 1 tasks: more than four hours
Day 1 respirator: Saw outdoors, more than 4 hours: APF 10. Jackhammer indoors, more than 4 hours: APF 10. Respirator for both tasks
Day 2 tasks: Same saw outdoors, 1.5 hours; same jackhammer indoors, 2 hours
Day 2 total: 1.5 + 2 = 3.5 hours: not more than four hours
Day 2 respirator: Saw outdoors, 4 hours or less: none. Jackhammer indoors: APF 10, whatever the duration
Medical exams: If Laborer A is required to wear the respirator on 30 or more days this year, make the initial exam available within 30 days of assignment, unless a qualifying exam was done in the last three years

Two fictional days for one worker on a concrete sub's crew, checked against Table 1.

The same hour of outdoor saw work needs a respirator on one day and not on the other, because the column follows the worker's total Table 1 time for the shift. Write each task and its row into the crew's job hazard analysis, send your written plan to the GC for its site-specific safety plan, and use the row as a toolbox talk. Concrete subs' bidding and billing is in how concrete subs bid and bill.

The bottom line

For each task on Table 1, follow the row exactly, picking the respirator column by where the work is and the worker's total Table 1 time that shift. For anything else, keep exposure at or below 50 µg/m³ and measure it. Either way, keep the written plan, the competent person, the housekeeping limits, the training and the medical exams.

Conflo has no dedicated safety tool (JHAs, safety plans) today; it runs bids, submittals and pay apps for commercial GCs and the subs they invite, free for subs. Join the waitlist, and see the subcontractor's guide for the rest of the job.

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Sources

29 CFR 1926.1153, Respirable crystalline silica (including Table 1) — eCFR (Office of the Federal Register). Read October 22, 2026.
Silica, Crystalline: Construction — Occupational Safety and Health Administration. Read October 22, 2026.

Questions

What is Table 1 in OSHA's silica rule?

Table 1 in 29 CFR 1926.1153(c) lists 18 common construction tasks, such as saws, drills, jackhammers, grinders and heavy equipment, with the engineering controls, work practices and respirator each requires. Following a task's row fully and properly is compliance for that task.

What is the permissible exposure limit for silica in construction?

50 micrograms of respirable crystalline silica per cubic meter of air as an 8-hour time-weighted average, with an action level of 25. The limit applies when the employer doesn't fully follow Table 1 or the task isn't listed.

Do you need a respirator when cutting concrete outdoors?

With a water-fed handheld saw outdoors, Table 1 requires no respirator for four hours or less a shift and APF 10 for more than four hours, counting all of the worker's Table 1 tasks that shift.

Does every contractor need a written silica exposure control plan?

Every employer covered by the rule does, whether it follows Table 1 or measures exposure. Contractors whose workers' exposure will stay below 25 µg/m³ under any foreseeable conditions are outside the rule.