OSHA’s Respirable Crystalline Silica 

Standard for Construction

Workers who are exposed to respirable crystalline silica dust are at increased risk 

of developing serious silica-related diseases. OSHA’s standard requires employers 

to take steps to protect workers from exposure to respirable crystalline silica.

What is Respirable Crystalline Silica?

Crystalline silica is a common mineral that is found 

in construction materials such as sand, stone, 

concrete, brick, and mortar. When workers cut, 

grind, drill, or crush materials that contain crystalline 

silica, very small dust particles are created. These 

tiny particles (known as “respirable” particles) can 

travel deep into workers’ lungs and cause silicosis, 

an incurable and sometimes deadly lung disease. 

Respirable crystalline silica also causes lung cancer, 

other potentially debilitating respiratory diseases 

such as chronic obstructive pulmonary disease, and 

kidney disease. In most cases, these diseases occur 

after years of exposure to respirable crystalline silica.

How are Construction Workers Exposed to 

Respirable Crystalline Silica?

Exposure to respirable crystalline silica can occur 

during common construction tasks, such as using 

masonry saws, grinders, drills, jackhammers and 

handheld powered chipping tools; operating vehiclemounted drilling rigs; milling; operating crushing 

machines; using heavy equipment for demolition 

or certain other tasks; and during abrasive blasting 

and tunneling operations. About two million 

construction workers are exposed to respirable 

crystalline silica in over 600,000 workplaces.

What Does the Standard Require?

The standard (29 CFR 1926.1153) requires 

employers to limit worker exposures to respirable 

crystalline silica and to take other steps to protect 

workers. Employers can either use a control 

method laid out in Table 1 of the construction 

standard, or they can measure workers’ exposure 

to silica and independently decide which dust 

controls work best to limit exposures in their 

workplaces to the permissible exposure limit (PEL).

What is Table 1?

Table 1 matches 18 common construction tasks 

with effective dust control methods, such as using 

water to keep dust from getting into the air or using 

a vacuum dust collection system to capture dust. In 

some operations, respirators may also be needed. 

Employers who follow Table 1 correctly are not 

required to measure workers’ exposure to silica 

from those tasks and are not subject to the PEL.

Table 1 Example: Handheld Power Saws

If workers are sawing silica-containing materials, 

they can use a saw with a built-in system that applies 

water to the saw blade. The water limits the amount 

of respirable crystalline silica that gets into the air.

Table 1: Specified Exposure Control Methods 

When Working With Materials Containing 

Crystalline Silica

Equipment/

Task 

Engineering and 

Work Practice 

Control Methods

Required 

Respiratory 

Protection 

and Minimum 

Assigned 

Protection 

Factor (APF) 

≤ 4 hrs/

shift

> 4 hrs/

shift

Handheld 

power saws 

(any blade 

diameter) 

Use saw equipped 

with integrated 

water delivery 

system that 

continuously feeds 

water to the blade.

Operate and 

maintain tool in 

accordance with 

manufacturer’s 

instructions to 

minimize dust 

emissions.

• When used 

outdoors.

• When used 

indoors or in an 

enclosed area.

None

APF 10 

APF 10

APF 10

Excerpt from Table 1 in 29 CFR 1926.1153

In this example, if a worker uses the saw outdoors 

for four hours or less per day, no respirator would be 

needed. If a worker uses the saw for more than four 

FactSheet
hours per day or any time indoors, he or she would 

need to use a respirator with an assigned protection 

factor (APF) of at least 10, such as a NIOSH-certified 

filtering facepiece respirator that covers the nose 

and mouth (sometimes referred to as a dust mask). 

See the respiratory protection standard (29 CFR 

1910.134) for information on APFs.

Alternative Exposure Control Methods

Employers who do not fully implement the control 

methods on Table 1 must: 

• Determine the amount of silica that workers 

are exposed to if it is, or may reasonably be 

expected to be, at or above the action level of 

25 μg/m3 (micrograms of silica per cubic meter 

of air), averaged over an 8-hour day;

• Protect workers from respirable crystalline silica 

exposures above the PEL of 50 μg/m3, averaged 

over an 8-hour day; 

• Use dust controls and safer work methods to 

protect workers from silica exposures above 

the PEL; and 

• Provide respirators to workers when dust 

controls and safer work methods cannot limit 

exposures to the PEL.

What Else Does the Standard Require?

Regardless of which exposure control method is 

used, all construction employers covered by the 

standard are required to:

• Establish and implement a written exposure 

control plan that identifies tasks that involve 

exposure and methods used to protect workers, 

including procedures to restrict access to work 

areas where high exposures may occur;

• Designate a competent person to implement 

the written exposure control plan;

• Restrict housekeeping practices that expose 

workers to silica, such as use of compressed 

air without a ventilation system to capture the 

dust and dry sweeping, where effective, safe 

alternatives are available;

• Offer medical exams—including chest X-rays 

and lung function tests—every three years for 

workers who are required by the standard to 

wear a respirator for 30 or 

more days per year; 

• Train workers on the health 

effects of silica exposure, 

workplace tasks that can 

expose them to silica, and 

ways to limit exposure; and 

• Keep records of workers’ 

silica exposure and 

medical exams.

Additional Information

Additional information on 

OSHA’s silica standard can be 

found at www.osha.gov/silica.

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 medium-sized 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. Consultants 

from state agencies or universities work with 

employers to identify workplace hazards, provide 

advice on compliance with OSHA standards, and 

assist in establishing and improving safety and health 

management systems. To locate the OSHA On-Site 

Consultation Program nearest you, call 1-800-321-

OSHA or 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.

Applying water to the blade of a 

handheld power saw reduces the 

amount of dust created when cutting.

DSG FS-3681 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.