CONTROL OF SILICA DUST IN CONSTRUCTION 

Stationary Masonry Saws 

Using a stationary masonry saw to cut bricks, concrete blocks, pavers, or other 

silica-containing materials can generate respirable crystalline silica dust. When 

inhaled over time, the small particles of silica can irreversibly damage the lungs. 

This fact sheet describes dust controls that can be used to minimize the amount 

of airborne dust when using stationary masonry saws as listed in Table 1 of the 

Respirable Crystalline Silica Standard for Construction, 29 CFR 1926.1153.

Engineering Control Method: Water applied continuously to the saw blade

Wet Cutting

When using a stationary masonry saw, wet 

cutting with an integrated water delivery system 

that continuously feeds water to the blade is an 

effective way to reduce exposure to silica dust. 

Many stationary masonry saws come equipped 

with a water basin that holds several gallons of 

water. A pump recirculates the water through a 

nozzle that directs a continuous stream onto the 

blade where it wets the material being cut and 

reduces the amount of dust generated.

Photo courtesy of OSHA

A worker cutting masonry block on a stationary masonry saw that 

continuously feeds water to the blade. 

The saw must be operated and maintained in 

accordance with the manufacturer’s instructions 

to minimize dust emissions. Focus on the 

following areas:

• Check that hoses are securely connected and 

are not cracked or broken.

• Ensuring that water flows at the rates 

recommended by the manufacturer. Water 

flow rates must be sufficient to minimize the 

release of visible dust.

• Adjust nozzles so that water goes to the blade 

and wets the cutting area.

• Rinsing or replacing water filters at 

recommended intervals.

• Replace basin water when it gets gritty or 

begins to silt up with dust.

• Inspect the saw blade before use to be sure 

it is in good condition and does not show 

excessive wear.

Indoors or in Enclosed Areas

Wet cutting indoors or in enclosed areas may 

not reliably keep silica exposures low, so extra 

ventilation or a means of exhaust may be needed 

to reduce visible airborne dust. Extra ventilation 

can be supplied by using:

• Exhaust trunks

• Portable exhaust fans

• Air ducts

• Other means of mechanical ventilation

Ensure air flow is not impeded by the 

movements of employees during work, or by 

the opening or closing of doors and windows. 

Position the ventilation to move contaminated air 

away from the workers’ breathing zones.

FactSheet
Electrical Safety. Where water is used 

to control dust, electrical safety is a 

particular concern. Use ground-fault circuit 

interrupters (GFCIs) and watertight, sealable 

electrical connectors for electric tools and 

equipment on construction sites.

Vacuum Dust Collection System (VDCS)

Some stationary masonry saws come equipped 

with a VDCS to capture the dust generated when 

sawing. For situations in which wet methods are 

not feasible, employers using a VDCS to control 

the dust must conduct an exposure assessment 

and may need to take additional action.

Respiratory Protection

When properly used, wet methods can 

effectively control silica dust. Therefore, Table 1 

in the silica standard does not require use of 

respiratory protection when using wet methods 

for stationary masonry saws.

For stationary saws used with a VDCS by 

employers not utilizing Table 1 control methods, 

respiratory protection may be required if exposure 

monitoring results indicate employee exposures 

above the permissible exposure limit (PEL) of 50 

μg/m3, calculated as an 8-hour time-weighted 

average. When using VDCS in these conditions, 

employers must put in place a written respiratory 

protection program in accordance with OSHA’s 

Respiratory Protection standard 29 CFR 1910.134.

Additional Information

For more information, visit www.osha.gov/silica

and see the OSHA Fact Sheet on the Crystalline 

Silica Rule for Construction, and the Small Entity 

Compliance Guide for the Respirable Crystalline 

Silica Standard for Construction.

OSHA can provide compliance assistance 

through a variety of programs, including technical 

assistance about effective safety and health 

programs, workplace consultations, and training 

and education. OSHA’s On-Site Consultation 

Program offers free, confidential occupational 

safety and health services to small and mediumsized businesses in all states and several 

territories across the country, with priority given 

to high-hazard worksites. On-Site consultation 

services are separate from enforcement and do 

not result in penalties or citations. To locate the 

OSHA On-Site Consultation Program nearest you, 

visit www.osha.gov/consultation.

How to Contact OSHA

Under the Occupational Safety and Health Act 

of 1970, employers are responsible for providing 

safe and healthful workplaces for their employees. 

OSHA’s role is to ensure these conditions for 

America’s working men and women by setting 

and enforcing standards, and providing training, 

education and assistance. For more information, 

visit www.osha.gov or call OSHA at 1-800-321-

OSHA (6742), TTY 1-877-889-5627.

DSG FS-3631 12/2017

This is one in a series of informational fact sheets highlighting OSHA programs, policies or 

standards. It does not impose any new compliance requirements. For a comprehensive list of 

compliance requirements of OSHA standards or regulations, refer to Title 29 of the Code of Federal 

Regulations. This information will be made available to sensory-impaired individuals upon request. 

The voice phone is (202) 693-1999; teletypewriter (TTY) number: (877) 889-5627.