Silica dust from cutting brick and concrete: what a careful masonry contractor does

Updated November 11, 2026 · KeystoneProGuide editorial team

Why is masonry dust a concern?

Because brick, block, stone, concrete and mortar contain crystalline silica, and cutting them turns it into dust fine enough to breathe. The Occupational Safety and Health Administration (OSHA) says respirable crystalline silica, particles at least 100 times smaller than ordinary sand, is created when cutting, sawing, grinding, drilling and crushing stone, rock, concrete, brick, block and mortar.

Workers who inhale it are at increased risk of serious disease. OSHA names four: silicosis, an incurable lung disease that can lead to disability and death; lung cancer; chronic obstructive pulmonary disease; and kidney disease. It estimates that about 2.3 million people in the United States are exposed to silica at work.

Which masonry jobs make silica dust?

OSHA's examples read like a list of masonry and concrete work: abrasive blasting with sand, sawing brick or concrete, sanding or drilling into concrete walls, grinding mortar, and cutting or crushing stone. At a house, that covers:

• Grinding out mortar joints for repointing.
• Cutting brick, block or stone to size.
• Saw-cutting or breaking up old concrete for a new driveway, walk or patio.
• Drilling into a foundation or concrete wall.
• Sandblasting masonry, which the National Park Service also warns strips the hard surface from brick.

What does the federal rule require of contractors?

OSHA's construction standard sets a limit of 50 micrograms of respirable silica per cubic meter of air, averaged over an 8-hour shift, and requires every covered employer to:

• Have a written exposure control plan that identifies dusty tasks and how workers are protected, including restricting access to areas where exposure may be high.
• Designate a competent person to carry out the plan.
• Restrict cleanup methods that raise dust where alternatives are feasible.
• Train workers, keep records, and offer medical exams to workers who must wear a respirator 30 or more days a year.

Employers can either follow the control methods set out for each task in Table 1 of the rule or measure exposure and choose their own controls.

What controls should you see on site?

Table 1 shows what OSHA expects for common masonry tools.

For the tuckpointing grinder, the rule also sets the dust collector's airflow at 25 cubic feet per minute or more per inch of wheel diameter, with a filter of 99 percent efficiency or better and a cyclonic pre-separator or filter-cleaning mechanism. OSHA's construction page sums up the principle for saws: applying water to the blade "substantially reduces the amount of dust".

Cleanup counts too. The rule says employers shall not allow dry sweeping or dry brushing that could add to exposure unless wet sweeping, HEPA-filtered vacuuming or other low-dust methods are not feasible, and it restricts the use of compressed air to clean clothes or surfaces.

Does the rule protect your household?

Not directly. The standard governs employers and their workers; it says nothing about homeowners, neighbors or occupants, and no Environmental Protection Agency consumer guidance on silica in home renovation was found for this guide. Because the rule is about workers, it is silent on dust that leaves the work area. Ask the contractor how they will keep the dust within it, and keep children and pets away while cutting is under way.

Do careful repointing methods help?

They reduce how much cutting is done. The General Services Administration's specification for repointing historic masonry has joints raked out by hand with chisels and mallets wherever possible, allowing power tools only after a demonstration that they cause no damage. Its masonry cleaning specification starts with water and soft brushes rather than abrasives. Those choices are made to protect old brick, but they also mean less grinding.

What should you ask a contractor?

• Which tasks on this job will create dust, and how will you control each one?
• Will saws be wet-cut? Will grinders have shrouds and dust collectors?
• Will workers wear respirators where the rule requires them?
• How will you clean up: vacuum, wet methods, or brooms?
• Will you keep the work area closed off, and protect open windows and vents nearby?

A contractor who has a written exposure control plan, as OSHA requires, should be able to answer in a sentence or two.

Is there anything else in old masonry to ask about?

Paint. If the house was built before 1978 and painted surfaces will be disturbed, the U.S. Environmental Protection Agency requires a paid contractor to be lead-safe certified, with limited exceptions such as exterior work disturbing 20 square feet or less.

For why this work is not a homeowner job, see whether to do it yourself or hire. The full list of hiring questions is in questions to ask. Contractors are on the masonry contractors page.

Sources

1. Silica, Crystalline - Overview, U.S. Occupational Safety and Health Administration
2. Silica, Crystalline - Construction, U.S. Occupational Safety and Health Administration
3. 1926.1153 - Respirable crystalline silica., U.S. Occupational Safety and Health Administration
4. Repointing historic masonry, U.S. General Services Administration
5. Cleaning historic masonry, U.S. General Services Administration
6. Common Problems with Brick Masonry, U.S. National Park Service
7. Renovation, Repair and Painting Program: Contractors, U.S. Environmental Protection Agency