MCAA Special Report: OSHA Proposed Rule on Crystalline Silica

Words: Dan KamysMCAA Special Report: OSHA Proposed Rule on Crystalline Silica

On Aug. 23, the U.S. Occupational Safety and Health Administration (OSHA) announced that it will soon publish a Notice of Proposed Rulemaking (proposed rule) aimed at curbing worker exposure to crystalline silica. Crystalline silica is a natural occurring component of soil, sand, granite and other minerals. According to OSHA, about 1.85 million construction workers are exposed to respirable crystalline silica annually. Exposure occurs during construction activities when workers are cutting, grinding, crushing or drilling materials that contain silica, such as concrete, masonry, tile or rock.

This MCAA special report provides a summary of OSHA’s proposed rule on crystalline silica in a question and answer format. It is not legal advice and is offered for general information purposes only. For advice on how the proposed rule may impact your construction operations, consult your safety advisor, insurance agent and/or legal counsel.

Why did OSHA publish this rule?

According to OSHA, its proposal “seeks to lower worker exposure to crystalline silica, which kills hundreds of workers and sickens thousands more each year.” OSHA estimates that, once the rule is fully implemented, it will “result in saving nearly 700 lives per year and prevent 1,600 new cases of silicosis annually.” OSHA’s current rule on silica was adopted in 1971 and has not been updated since that time.

Why is respirable crystalline silica dangerous?

Exposure to crystalline causes silicosis, an incurable lung disease caused by tiny silica particles, small enough to inhale. Once inhaled, the particles can cause scarring and damage to the lungs. This reduces the lungs’ ability to take in oxygen and makes an individual more susceptible to lung infections and other diseases, including lung cancer.

What construction activities are most likely to expose workers to silica?

Many common construction operations can expose workers to silica, including using masonry saws, using hand-operated grinders, tuckpointing, using jackhammers, using rotary hammers or drills, operating vehicle-mounted drills, drywall finishing using silica-containing materials, and using heavy equipment during earthmoving. Note that employees, who are in proximity to such activities, even though not directly involved, also may be exposed to silica.

What will the OSHA proposed require of construction employers?

Generally, OSHA’s proposed rule would require construction employers to measure workers’ exposure to silica; train workers on how to avoid exposure to silica; limit worker access to areas where they could be exposed to silica; provide technological means to protect workers, such as dust controls and respirators; offer medical exams to workers exposed to silica; and keep records on worker exposure and medical exams.

You said that construction employers will have to measure workers’ exposure to silica. When does that requirement apply?

Under OSHA’s proposed rule, a construction employer would have to measure and keep records of the amount of silica that its workers are exposed to if it may be at or above 25 ??g/m3 (micrograms of silica per cubic meter of air), averaged over an 8-hour day. This is known as the “action level.” A construction employer would have to protect its workers from respirable crystalline silica exposures above a permissive exposure level of 50 ??g/m3, averaged over an 8-hour day. This is known as the PEL. It is our understanding that at the proposed action level, all works on a construction jobsite would fall under this standard.

Under OSHA’s proposed rule, what procedures will I have to use to protect workers?

OSHA’s proposed rule essentially provides four ways to protect workers from crystalline silica:

  1. Train workers on the dangers of silica exposure and ways to mitigate exposure.
  2. Limit workers’ access to areas where they could be exposed above the PEL.
  3. Use dust controls to protect workers from silica exposures above the PEL.
  4. Provide respirators to workers when dust controls cannot limit exposures to the PEL.

In its proposed rule, OSHA provides some flexibility to employers on how to comply. For example, an employer would not have to measure its workers’ exposure to silica if it chooses to control silica dust using OSHA-designated methods to control silica dust on specified construction activities. Alternatively, a construction employer could choose to measure its workers’ exposure to silica and independently decide which dust controls work best on its jobsites.

You also said that an employer would have to offer medical exams to workers exposed to silica.

That’s right. OSHA’s proposed rule would require an employer to offer medical exams, including chest X-rays and lung function tests, to workers who have been exposed to silica above the PEL for 30 or more days per year.

You also mentioned recordkeeping. What kind of recordkeeping will I have to keep?

OSHA’s proposed rule requires employers whose workers are exposed to silica to keep records concerning worker exposure to silica and the medical exams provided to these workers. Again, the rule sets forth significant detail.

What is MCAA doing about OSHA’s proposed silica rule?

To begin with, MCAA staff and advisors are reading and studying the 577-page proposed rule. The document is not just long, but it is complex, offering several alternatives for construction employers. In its evaluation, MCAA will determine whether OSHA’s proposed rule:

  • Adequately addresses the unique nature of the masonry construction with non-fixed worksites and transient employees.
  • Is technologically feasible in the masonry industry with its varied tasks, operations and controls.
  • Is economically feasible in the masonry industry, which is dominated by small firms.
  • Is consistent with other federal government rules and regulations.

In addition, MCAA is a member of the Construction Industry Safety Coalition, a construction industry-wide coalition, which is coordinating an industry response to OSHA’s proposed silica rule. The Coalition already has retained a firm to conduct a technological and economic feasibility study of OSHA’s proposed rule.

Once MCAA conducts a thorough study of OSHA’s proposed rule, the Association will prepare and submit comments to OSHA.

What can I do to help?

First, as a construction employer, you should first evaluate your own jobsites, both to assure that you are protecting your employees against exposure to respirable crystalline silica and that you are complying with current OSHA requirements.

Then, you should evaluate the proposed OSHA rule to determine how you would comply, how much it would cost, and the impact on your employees and your company. Share that information with MCAA President Jeff Buczkiewicz at or 800-536-2225.

Finally, you can file your own comments with OSHA by visiting the Federal e-Rulemaking Portal at!home, entering Docket ID# OSHA-2010-003, and then submitting your comments; remember your comments will be part of the public record.

Where can I learn more about OSHA’s proposed rule on crystalline silica?

OSHA has established a Web site on its proposed rule at, where you can get a copy of the proposed rule, OSHA-prepared fact sheets, and even link to the site where you can file your own comments. Of course, MCAA also will continue to provide its members with information, as it completes its evaluation of OSHA’s proposed rule and files its own comments with OSHA.

The MCAA would like to thank the ASA (A Construction Industry Safety Coalition member) for preparing these questions and answers.

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