OSHA silica compliance for countertop fabrication shops: what the rule requires, step by step

A U.S. countertop shop must keep every worker's exposure to respirable crystalline silica at or below 50 µg/m³ averaged over an 8-hour shift, the OSHA permissible exposure limit (PEL). To prove it, the shop has to assess exposures (usually with air sampling), control dust with engineering methods such as wet cutting and dust extraction, write and yearly review an exposure control plan, provide fit-tested respirators where controls are not enough, avoid dry sweeping and compressed air, offer medical exams to anyone exposed at or above the 25 µg/m³ action level for 30 or more days a year, train workers and keep records for 30 years. Shop work falls under 29 CFR 1910.1053. Cutting and grinding at a customer's site falls under the construction standard, 29 CFR 1926.1153. There is no small-business exemption.

This article explains the federal rule. State plans can be stricter, and California is much stricter for engineered stone. See silica and silicosis for why the rule exists and for California's rules. For anything you are unsure of, read the standard on osha.gov or call your OSHA area office or state plan.

Which standard applies to you

OSHA published two versions of the silica rule in 2016 with the same exposure limits:

Most fabricators need both: one program for the shop and one for install crews.

The general industry standard has two narrow exits. It does not apply if you have objective data showing exposure stays below 25 µg/m³ under any foreseeable conditions, which is hard to show for stone cutting. It also lets you follow the construction rule's Table 1 for a task that is indistinguishable from a listed construction task and is not performed regularly in the same environment. Routine shop cutting does not fit that description.

About 20 states run their own OSHA-approved plans for private employers (California, Washington, Oregon, Michigan and others). Their rules must be at least as protective as federal OSHA and can go further.

The numbers that matter

TWA means time-weighted average: the average concentration over the shift, so a short dusty task and a long clean one are averaged together. A µg/m³ is a microgram per cubic meter. At 50 µg/m³ you see nothing in the air. If you can see dust, you are probably well over the limit.

For scale: dry-grinding engineered stone with no controls can put a worker's breathing zone at hundreds or thousands of µg/m³, many times the PEL. Well-run wet shops often measure below the action level at the saw, but results depend on the task, the material and how well the controls are maintained. Only sampling tells you where your shop stands.

Step 1: assess exposure

You must know each worker's exposure. The standard gives two options.

Performance option. Use any combination of air monitoring data and objective data (industry studies or data from very similar operations) that accurately characterizes exposure. Objective data must truly match your materials, machines and controls. For dry or hand work on engineered stone, it rarely does.

Scheduled monitoring option. Take personal air samples for each job, shift and work area, then repeat on a schedule:

You must reassess whenever something changes that could raise exposure: a new material (such as a jump in quartz or quartzite volume), a new machine, a change in water or extraction, a new process such as dry polishing, or different staffing.

How sampling works. A worker wears a small pump on the belt that pulls air through a filter cassette clipped near the mouth for the full shift. An accredited lab analyzes the filter for quartz and cristobalite, usually by NIOSH Method 7500 (X-ray diffraction) or 7602 (infrared). Where several people do the same task with the same material and controls, you may sample a representative worker from that group. Most shops hire an industrial hygienist for the first survey. OSHA's free On-Site Consultation Program can also sample and advise without issuing citations.

Within 15 working days of getting results, notify each affected worker in writing or post the results where they can see them. If a result is above the PEL, the notice must say what you are doing to fix it.

Step 2: control dust at the source

OSHA requires you to use feasible engineering and work-practice controls first. Respirators only fill the gap that remains.

Wet methods. Water at the point of cut is the backbone of silica control. It catches dust before it becomes airborne and also cools the tool.

• Bridge saws, sawjets, CNC routers and edge polishers: continuous water flow aimed at the point of contact, at the machine maker's rated flow. A clogged nozzle or a line turned down to "keep the floor dry" defeats the control.

• Hand tools: water-fed grinders and polishers for edge work, sink cutouts and seams.

• Keep water on for a few seconds after the tool stops, and do not let slurry dry on tables, floors or clothing.

Local exhaust ventilation (LEV). Dust extraction at the tool, such as a shroud on a grinder connected to a vacuum with a HEPA filter, or an enclosure with exhaust on a CNC. A standard shop vacuum is not enough, because its filter lets the finest particles through. NIOSH field studies in fabrication shops found that water and on-tool extraction together reduced dust more than either one alone, especially for grinding.

Enclosure and isolation. Enclosed CNC machines, curtains or walls around dusty stations, and keeping other workers away from grinding.

General ventilation. Fans and makeup air dilute what escapes, but dilution alone does not control silica at the source.

Work practices. Never dry-cut. Do not run grinders dry "just to finish." Check water flow and vacuum suction daily. Change filters on schedule. Keep dusty work away from the break area, and do not eat or drink where silica dust is present.

For cutting equipment, see bridge saws and sawjets and CNC machining. For the water system behind wet cutting, see water recycling and slurry.

Step 3: write the exposure control plan

Every employer covered by the standard needs a written exposure control plan. OSHA inspectors ask for it first. It must describe:

1. Each task that involves exposure to respirable crystalline silica.

2. The engineering controls, work practices and respiratory protection used for each task.

3. The housekeeping measures used to limit exposure.

Make it specific. "Use water" is not a plan. "Bridge saw 1: continuous water at the blade, flow checked at start of shift by operator; sink cutouts on CNC 2 (enclosed, wet); hand edge work only with water-fed polisher; HEPA vacuum for cleanup" is a plan. Name the person who owns it.

Review it at least once a year and update it when tasks, materials or controls change. Make it available to workers and their representatives. The Natural Stone Institute and OSHA's small entity compliance guide for the silica rule both offer sample plans to adapt.

Step 4: set up regulated areas where exposure exceeds the PEL

Where exposure is, or can reasonably be expected to be, above the PEL, mark off a regulated area. Post the required warning signs at entrances, limit entry to authorized people, and make everyone who enters wear an appropriate respirator. If you find yourself needing regulated areas for routine work, treat it as a sign the engineering controls need fixing.

Step 5: provide respirators where controls fall short

You must provide respirators when exposure is above the PEL while controls are being installed, for tasks where controls are not feasible, when all feasible controls still leave exposure above the PEL, and in regulated areas. Then you need a full respiratory protection program under 29 CFR 1910.134:

• A written program with a named administrator.

• A medical evaluation (a questionnaire reviewed by a licensed health care professional, or an exam) before fit testing.

• A fit test before first use, at least every 12 months, and whenever the face or respirator model changes.

• Training on use, limits, cleaning, storage and filter changes.

A respirator's assigned protection factor (APF) tells you how much it reduces exposure when it fits and is worn correctly. Multiply the APF by the PEL to get the highest concentration it can be used in.

Practical points:

• Many shops choose P100 filters for grinding and polishing. They filter at least 99.97% of test particles and hold up better around oil mist. An N95 filter is also approved for silica, but it still only gets APF 10 as a half-mask.

• Tight-fitting respirators may not be worn with a beard or stubble where the mask seals. Bearded workers need a loose-fitting PAPR hood or helmet.

• If a worker wears a respirator voluntarily where it is not required, give them OSHA's Appendix D information. For any respirator other than a filtering facepiece, voluntary use also requires a medical evaluation and a cleaning and storage routine.

• In California, Section 5204 requires much higher-protection respirators (generally APF 1000 class PAPRs) for high-exposure tasks on engineered stone and high-silica natural stone.

Step 6: clean up without making dust

The standard bans dry sweeping and brushing where wet sweeping, HEPA vacuuming or other low-dust methods are feasible, and bans compressed air for cleaning clothing or surfaces unless it is used with ventilation that captures the dust or no alternative is feasible. In a stone shop, feasible alternatives almost always exist, so treat both as banned.

• Squeegee and hose or wet-mop floors.

• Clean up slurry before it dries.

• Use HEPA-filtered vacuums (many shops choose H-class units) for dust.

• Keep dusty clothes out of the office and vehicles.

Step 7: offer medical surveillance

Every worker who will be exposed at or above the action level for 30 or more days a year must be offered medical exams, at no cost, at a reasonable time and place. Under the construction rule, the trigger is being required to wear a respirator for 30 or more days a year.

The worker gets the full results. The doctor may refer the worker to a lung or occupational medicine specialist. Budget roughly $200 to $600 per worker per exam (2026 U.S. ranges, varying with region and whether a CT scan is added).

Step 8: train workers

Silica must be part of your hazard communication program, with safety data sheets available for every slab material and product. Workers who are covered by the standard must be able to show they understand:

• The health hazards of silica (lung disease, cancer, kidney and immune effects).

• The specific tasks in your shop that expose them.

• The controls, work practices and respirators you use.

• The contents of the standard and of your exposure control plan.

• The purpose of medical surveillance.

Train in a language and vocabulary workers understand, before they start dusty work, and again when tasks change. Annual refresher training is standard practice. A sign-in sheet with the topics, the trainer and a short practical check is the proof an inspector looks for. See shop safety program for building the training schedule.

Step 9: keep records

If the business closes or is sold, exposure and medical records have to go to the successor, or be offered to NIOSH. Store them where they survive staff turnover, not in one person's email.

Install crews and the construction standard

Job-site cutting falls under 29 CFR 1926.1153. Its Table 1 lets a crew skip air monitoring for a listed task if it uses the exact control listed and the listed respirator. Two rows matter most for countertop installers:

A kitchen install is indoor work, so a shrouded grinder on a proper HEPA vacuum is the practical Table 1 route. Any task done differently from Table 1, such as a dry cut, needs a real exposure assessment. The construction rule also requires a competent person, someone who can spot silica hazards on site and has authority to fix them, and a written plan that covers the crew's tasks.

Better still, do as much cutting as possible in the shop. Accurate templating and faucet holes drilled before install reduce site cutting. See installation crews.

Inspections and penalties

OSHA has run a National Emphasis Program on silica since February 2020, which targets cut stone and stone product manufacturing (NAICS 327991) for programmed inspections. In September 2023 it added a focused inspection initiative for engineered-stone fabrication and installation. Inspections are unannounced. Workers may speak to the inspector privately.

Maximum federal penalties per violation (as of September 2026):

These are the January 2025 amounts. OSHA made no inflation adjustment in 2026. OSHA reduces proposed penalties for small employers, and for good faith and history, and many citations settle at an informal conference. You have 15 working days after receiving a citation to contest it.

The most common silica findings in stone shops are predictable:

1. No written exposure control plan, or a generic one.

2. No exposure assessment.

3. Dry sweeping or compressed-air cleanup.

4. Respirators in use without a written program, medical evaluation or fit test.

5. No medical surveillance offered.

6. No proof of training, or training in a language workers do not understand.

7. Wet systems that are clogged, throttled or bypassed.

What compliance costs

Typical 2026 U.S. ranges for a small shop (roughly 3 to 10 workers). Actual costs depend on region, shop size and how good the existing controls are.

Price these into overhead like any other cost of doing business. See cost structure, labor and overhead.

Common mistakes

• Thinking wet cutting alone is compliance. Water is the main control, but the plan, assessment, housekeeping, training and medical program are separate requirements.

• Using Table 1 in the shop. It belongs to the construction standard.

• Handing out N95s without a program. Required respirator use needs medical evaluation, fit testing and training.

• Sampling once and never again. A move from mostly granite to mostly quartz is a change that calls for reassessment.

• Ignoring the finishing bench. Hand grinding and polishing is often the dustiest job in the shop.

FAQ

Does a two-person shop have to follow the silica standard? Yes. The rule has no small-employer exemption. Small shops can get free, confidential help from OSHA's On-Site Consultation Program, which is separate from enforcement.

If I only cut granite and marble, am I covered? Granite can contain up to about 45% crystalline silica, and some marbles contain quartz veins, so you are covered unless objective data shows exposures stay below 25 µg/m³ under any foreseeable conditions. Most shops cannot show that.

Can I stop air monitoring once my results are low? Under the scheduled option, yes, after two consecutive non-initial results below the action level taken at least 7 days apart. You must reassess when materials, equipment or processes change.

Does the employer see a worker's X-ray results? No. The employer receives only the doctor's written opinion on the exam date, compliance with the standard and any respirator limits, unless the worker authorizes more.

Do I need a competent person in the shop? The general industry standard does not require one by name. The construction standard does, for job sites. Naming a responsible person for the shop program is still sensible.

What changes if my shop is in California? Cal/OSHA's Section 5204 adds mandatory wet methods, PAPR-class respirators for high-exposure tasks on engineered stone and high-silica natural stone, and 24-hour reporting of silicosis cases. SB 20 adds training attestations from July 2026 and shop certification by July 2027. A ban on engineered stone above 1% silica was proposed in September 2026. See silica and silicosis.