Respirable Silica Controls
The Table 1 engineering controls, the respirator, the 50 microgram exposure limit, the water flow the saw needs, the housekeeping bans, and the written program under OSHA 1926.1153.
A masonry saw needs water at the blade, and 1.5 gallons per minute is the baseline. Jackhammering and dry grinding want a half-mask with P100, dry sweeping is banned, and the 8-hour exposure limit is 50 micrograms per cubic meter.
How the math works
- The rule (1926.1153): the construction standard for respirable crystalline silica sets a 50 microgram per cubic meter 8-hour TWA PEL with a 25 microgram action level, and it gives two compliance paths: the Table 1 engineering-control route in (d), and the measured-exposure route in (f) and (g). Table 1 covers the common construction tasks and sets the controls and the respirator on each row.
- Table 1 controls (1926.1153(d), Appendix 1): sawing with water at the blade, jackhammering with a shroud and water, grinding with a shroud and HEPA dust collection, hand-tool work with water suppression, and demolition in a filtered pressurized cab are the rows. Every control on the row must be in place, the PPE on the row is required, and a row half-implemented is not compliance.
- Water (Table 1): 1.5 gpm is the baseline volume at the blade on a masonry saw, and the larger saws, the core rigs, the floor saws, and the wall saws take the manufacturer volume, which is higher. The water goes to the cutting point on a shroud, and a hand-held hose, a fog nozzle, and a sponge on the blade are not a water delivery system.
- Prohibited methods (1926.1153(e)): sand blasting with silica sand is prohibited, dry sweeping is prohibited, compressed air for dust removal is prohibited, and mechanical crushing and demolition in a machine without a filtered, pressurized, closed cab are outside the Table 1 rows.
- Program and medical (1926.1153(g), (i)): a written exposure control plan with a competent person is required on construction silica work, training is on the tasks, controls, respirators, and restrictions, exposure assessment is on the tasks outside Table 1, and medical surveillance (a chest X-ray, a spirometry, and the TB and Beryllium questions) applies to crew who wear a respirator 30 days or more a year above the action level.
Do I need water when cutting pavers or block?
On a masonry saw, yes, under Table 1: water delivered at the blade at a volume that keeps the dust out of the breathing zone, with a saw shroud and a water delivery system. A dry cut on a masonry saw is not a Table 1 task, so the exposure is measured, and the on-tool HEPA dust collector is the control that gets a dry cut back to a row.
What respirator for silica dust?
The Table 1 row sets it: N95 on the short water-suppressed tasks under 4 hours, and a half-mask with P100 cartridges on jackhammering, scaling, dry grinding, tuckpointing, demolition ground crews, and any Table 1 task run over 4 hours. A PAPR with a HEPA cartridge is the option for facial hair and glasses, and a fit test and a seal check are required on all of them.
Is dry sweeping allowed on a jobsite?
No. Dry sweeping, compressed air blow-down, and sand blasting with silica sand are all prohibited under 1926.1153(e) on silica work. A HEPA vacuum, wet methods, and a floor rinse are the cleanup, and the filter change on a HEPA vacuum is itself a dust event with a respirator on.