Silica Dust Control When Cutting or Grinding

Purpose

Respirable crystalline silica is the one hazard on a concrete crew that gives no feedback at the moment of exposure. The particles reaching deep lung are too small to see, the cut feels normal, and the disease shows up ten to thirty years later in someone who long since stopped cutting. That gap is why this cannot run on judgment: a crew cannot feel whether today was a bad day. The practical answer is not air monitoring, a laboratory program a small shop cannot run mid-job. It is 29 CFR 1926.1153 Table 1, which trades the assessment obligation for a specified control per task, fully implemented. This procedure makes that trade real by verifying the control is running, not just present on the truck.

Scope

Covers cutting, sawing, grinding, drilling, chipping and demolition of concrete, block and masonry on residential and light commercial work, plus the housekeeping and slurry handling that follow: sawcutting joints, edge and surface grinding, coring, dowel drilling and chipping repairs.

It does not cover abrasive blasting or tuckpointing mortar removal, which carry their own Table 1 rows and higher respiratory requirements, or the shop's written exposure control plan and medical surveillance program, which this procedure executes but does not create. It also does not reach a homeowner or bystander through OSHA, whose duties run to your employees; the duty toward a customer in their own driveway is the ordinary duty of care, discharged by keeping them clear.

Roles and responsibilities

Procedure

1. Name the task and find its Table 1 row before the tool comes out. Identify which task is about to happen, indoors or outdoors, and for how much of the shift, then read the matching row of Table 1 in 29 CFR 1926.1153. Acceptance: task, location, expected duration above or below four hours, and the row's control and respirator requirement written on the day's log. Wrong looks like "we are cutting some concrete" without the indoor and duration split, which is what changes the respirator answer; stop rule, no row identified, no cutting, and a task not on Table 1 goes to the plan's alternative path rather than proceeding uncontrolled. Hazard: a paper step, but skipping it puts an unprotected person into a plume, so it happens before the tool leaves the truck.

2. Verify the control hardware actually meets the row. Check the requirement the row names, not the general idea of it. Acceptance: for a water-controlled task, an integrated water delivery system continuously feeding the blade or grinding surface, with a supply sized to the cut; for a handheld grinder on dust collection, a commercially available shroud plus a collector providing 25 cubic feet per minute or greater per inch of wheel diameter, a filter of 99 percent or greater efficiency, and a cyclonic pre-separator or filter-cleaning mechanism. Wrong looks like a shop vacuum with a paper bag pressed into service; stop rule, hardware short of the row is not used, and the task switches to the other control the row allows or waits for compliant equipment. Hazard: dumping a used filter or bag releases the dust you captured, so it is changed outdoors into a sealed bag by someone wearing the respirator the task called for.

3. Set respiratory protection to the row, and to the program behind it. Where the row calls for a respirator, that is an assigned protection factor of 10 for a half-mask air-purifying respirator on most concrete tasks. Acceptance: the respirator the row names, worn by everyone in the task area, each wearer holding a current medical evaluation and a fit test within twelve months, since 29 CFR 1910.134(f)(2) requires fit testing at least annually and before first use. Wrong looks like a nuisance dust mask handed out as respiratory protection; stop rule, no fit test on file, no task. Hazard: facial hair along the sealing surface breaks the seal, so a worker who cannot achieve one is reassigned rather than told to try harder.

4. Restrict access and mark the area before the first cut. Set and post the boundary the plan specifies, keep other trades and the customer outside it, and position the work so the plume blows away from occupied space. Acceptance: boundary posted, nobody inside without the task's respiratory protection, and openings and air intakes closed or covered where the work is near them. Wrong looks like a saw running ten feet from an open garage door with the homeowner watching; stop rule, stop cutting the moment anyone crosses the boundary and restart once they are clear. Hazard: a saw throws fragments and a cut-off wheel can burst, so the boundary accounts for both and everyone inside wears ANSI Z87.1 eye protection.

5. Cut with the control running, and stop when it stops. Start the water or the vacuum before the blade contacts the work and keep it running for the whole cut. Acceptance: visible water at the blade or grinding surface continuously, or suction confirmed at the shroud with the hose unkinked and the filter cleaned per the manufacturer, and no visible plume. Wrong looks like a saw tank running dry twenty minutes into a joint run, which the operator often notices only as a change in the sound; stop rule, the moment water or suction is lost, stop cutting, correct it and record the interruption, because a cut made without the control is an uncontrolled exposure the crew is entitled to know about. Hazard: a wet saw is an electrical tool in standing water, so it runs on a GFCI-protected circuit, and the blade guard stays on with the operator behind, never beside, the blade line.

6. Handle the slurry and the debris wet, and never dry-sweep it. Contain slurry before it spreads, collect it wet, and clean with wet methods or a HEPA-filtered vacuum. Acceptance: no dry sweeping or dry brushing where it could contribute to exposure, which 29 CFR 1926.1153(f) prohibits unless wet sweeping or HEPA vacuuming is not feasible, and no compressed air for cleaning unless paired with a ventilation system that captures the dust or no alternative is feasible. Wrong looks like slurry left to dry overnight and swept up next morning, turning yesterday's captured dust into today's exposure; stop rule, wet dried slurry down before touching it. Hazard: slurry is caustic like fresh concrete, near pH 12 to 13, so waterproof gloves and boots are worn and it is kept out of storm drains and off landscaping.

7. Log the day and feed the program. Record what was done, by whom, for how long, with which control, and close the loop on any interruption. Acceptance: the day's log complete, the competent person's inspection noted, and any employee approaching thirty days a year of required respirator use flagged to the safety lead, since 29 CFR 1926.1153(h) makes medical surveillance available at that threshold. Wrong looks like a log filled in from memory on Friday, which loses the interruptions that matter most; stop rule, an incomplete log is finished before the crew leaves. Hazard: none here, though this step decides whether the next one is protected.

The record this produces

One silica control log per job day. Fields: job, date, competent person named, each task with its Table 1 row, indoor or outdoor, start and stop times and duration, the control used and the equipment identification, the step 2 verification with the measured or nameplate figure beside the requirement, respirator type with each wearer's fit-test date, boundary and signage, any interruption of the control with its duration and what was done, slurry handling, and the operator's and crew leader's initials.

It goes on the job record and, in copy, into the shop's exposure control plan file. The safety lead reads it to keep fit tests and medical surveillance ahead of the work. An OSHA compliance officer reads it as evidence that Table 1 was fully implemented, which is the whole basis for not owing an exposure assessment. And a former employee's physician may read it decades later, which is the reader that makes it a record rather than a formality.

One pass, with a step that failed

A residential driveway replacement: sawcutting control joints outdoors with a walk-behind saw, and about two hours of edge grinding outdoors with a 5 in handheld grinder to clean the tie-in against the existing apron. Step 1 named both rows: the walk-behind saw outdoors with an integrated water delivery system feeding continuously, and the handheld grinder for a use other than mortar removal, which the row lets the shop control either with integrated water or with a shroud and dust collection.

Step 2 failed on the grinder. The wheel is 5 in, so the collector requirement is 5 x 25, or 125 cubic feet per minute and up. The truck's vacuum carries a nameplate rating of 105 cfm, which is 84 percent of the requirement and short whatever the sales sheet says. The crew leader took the stop rule and did not run it. The task itself did not stop, because the same row offers the water option: the crew fitted the water-fed attachment and ran the grinder wet, putting the task back inside Table 1 without waiting on equipment. Both the failure and the substitution went on the log with the two figures beside each other.

The rest ran clean. The saw's water ran continuously through 96 lineal feet of joint with the tank topped up twice, and no plume appeared. The boundary was set at the driveway edge with the homeowner asked to stay inside and told plainly why, which is ordinary duty of care rather than an OSHA requirement. Slurry was squeegeed wet to a collection point and removed the same day. Neither task required a respirator under its row outdoors, and that is a conclusion drawn from the row rather than from how the air looked.

Had the crew run the 105 cfm vacuum anyway, the failure would not have been visible. A shroud with weak suction still captures most of what a grinder throws, so the work looks controlled, and the fraction that matters is the one too fine to see. The shop would also lose the Table 1 trade: a control not fully implemented sends the task to the alternative path, where the employer owes an exposure assessment it cannot produce after the fact.

When the job does not match Table 1

The task is not on Table 1: the plan's alternative exposure control path applies, limiting exposure to the permissible exposure limit of 50 micrograms per cubic meter as an eight-hour time-weighted average by objective data or air sampling, and that is a decision for the safety lead before the day starts. Work moves indoors partway through: the row changes, most commonly by adding a respirator, so re-read it rather than carry the outdoor answer inside. The duration crosses four hours unexpectedly: the requirement changes at that line for several tasks, so the crew stops there and reassesses. And where a customer or another trade will not leave the boundary, the work stops until they do, with the reason named in plain terms rather than a finger pointed at a sign.

References

• 29 CFR 1926.1153, respirable crystalline silica in construction: Table 1 specified exposure control methods, housekeeping restrictions at (f), the written exposure control plan and competent person at (g), and medical surveillance at (h).
• 29 CFR 1910.134 for the respiratory protection program, including the annual fit-testing requirement at (f)(2) and medical evaluation before use.
• 29 CFR 1910.1200 hazard communication, which 1926.1153(i) uses for training on silica's cancer, silicosis, lung and kidney effects.
• Tool manufacturer instructions for the specific saw, grinder or collector, which Table 1 requires the tool be operated and maintained in accordance with.
• See related: the reinforcement placement verification SOP and the formwork stripping SOP.