OSHA

OSHA Crystalline Silica Rule : Construction

February 12, 2018

OSHA is issuing two standards to protect workers from exposure to respirable crystalline silica—one for construction, and the other for general industry and maritime—in order to allow employers to tailor solutions to the specific conditions in their workplaces.

Who is affected by the construction standard?

About two million construction workers are exposed to respirable crystalline silica in over 600,000 workplaces. OSHA estimates that more than 840,000 of these workers are exposed to silica levels that exceed the new permissible exposure limit (PEL).

Exposure to respirable crystalline silica can cause silicosis, lung cancer, other respiratory diseases, and kidney disease. Exposure can occur during common construction tasks such as using masonry saws, grinders, drills, jackhammers and handheld powered chipping tools; operating vehicle-mounted drilling rigs; milling; operating crushing machines; and using heavy equipment for demolition or certain other tasks.

Without dust controls, using a handheld power saw to cut concrete
can expose workers to high levels of respirable crystalline silica.

The construction standard does not apply where exposures will remain low under any foreseeable conditions; for example, when only performing tasks such as mixing mortar; pouring concrete footers, slab foundation and foundation walls; and removing concrete formwork.

What does the standard require?

The standard requires employers to limit worker exposures to respirable crystalline silica and to take other steps to protect workers. The standard provides flexible alternatives, especially useful for small employers. 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 to the PEL in their workplaces.

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 where feasible 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 work operations that result in silica exposure and ways to limit exposure.
• Keep records of workers’ silica exposure and medical exams.

What is Table 1?

Table 1 matches common construction tasks with
dust control methods, so employers know exactly
what they need to do to limit worker exposures
to silica. The dust control measures listed in the
table include methods known to be effective, like
using water to keep dust from getting into the
air or using ventilation 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
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.

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 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. In this case, a NIOSH-certified filtering
facepiece respirator that covers the nose and
mouth (sometimes referred to as a dust mask)
could be used. If a worker needs to use a
respirator on 30 or more days a year, he or she
would need to be offered a medical exam.

Alternative exposure control methods

Employers who do not use control methods in
Table 1 must:
• Measure the amount of silica that workers are
exposed to if it may be at or above an action
level of 25 μg/m3 (micrograms of silica per
cubic meter of air), averaged over an eighthour
day.
• Protect workers from respirable crystalline
silica exposures above the permissible
exposure limit of 50 μg/m3, averaged over an
eight-hour day.
• Use dust controls to protect workers from
silica exposures above the PEL.
• Provide respirators to workers when dust
controls cannot limit exposures to the PEL.

When are employers required to comply
with the standard?

Construction employers must comply with all
requirements of the standard by June 23, 2017,
except requirements for laboratory evaluation of
exposure samples, which begin on June 23, 2018.

Additional information

Additional information on OSHA’s silica rule can
be found at www.osha.gov/silica.
OSHA can provide extensive help 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
and 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 (6742)
or visit www.osha.gov/dcsp/smallbusiness.
For more information on this and other healthrelated
issues impacting workers, to report an
emergency, fatality, inpatient hospitalization, or to
file a confidential complaint, contact your nearest
OSHA office, visit www.osha.gov, or call OSHA at
1-800-321-OSHA (6742), TTY 1-877-889-5627.