ORIGIN: Moldex Technical Services Department


The Occupational Safety and Health Administration (OSHA) issued a final rule to help curb various silica-related diseases including silicosis in America’s workers by limiting their exposure to respirable crystalline silica.

About 2.3 million workers are exposed to respirable crystalline silica in their workplaces, including 2 million construction workers who drill, cut, crush, or grind silica-containing materials such as concrete and stone, and 300,000 workers in general industry operations such as brick manufacturing, foundries, and hydraulic fracturing, also known as fracking.

Key Provisions of New Standards With Regard To Respiratory Protection:

  • Reduces the permissible exposure limit (PEL) for respirable crystalline silica to 50 micrograms per cubic meter of air, averaged over an 8-hour shift.
  • Requires employers to provide respirators when engineering controls cannot adequately limit exposure.

Two Different Standards

OSHA developed 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 conditions in their workplaces.

Construction industry stakeholders indicated the need for guidance and a standard that is different than a standard for general industry. Among their concerns was the impracticality of exposure monitoring based on short duration of task and constantly changing conditions, such as weather, job sites and materials. In response OSHA developed Table 1. Table 1 is a flexible compliance option that effectively protects workers from silica exposures. It identifies 18 common construction tasks that generate high exposures to respirable crystalline silica and for each task, specifies engineering controls, work practices, and respiratory protection that effectively protect workers. Employers who fully and properly implement the engineering controls, work practices, and respiratory protection specified for a task on Table 1 are not required to measure respirable crystalline silica exposures to verify that levels are at or below the PEL for workers engaged in the Table 1 task. See Table 1. Exposure Control Methods for Selected Construction Operations at this link.



1532.3. Occupational Exposures to Respirable Crystalline Silica.

530.1. Control of Employee Exposures from Dust-Generating Operations Conducted on Concrete or Masonry Materials.

5204. Occupational Exposures to Respirable Crystalline Silica.


OSHA released a Small Entity Compliance Guide for General Industry and Maritime to help small business employers comply with the agency’s Final Rule to Protect Workers from Exposure to Respirable Crystalline Silica. The guide describes the steps that employers are required to take to protect employees in general industry and maritime from the hazards associated with silica exposure. These requirements include: assessing worker exposures; using engineering and work practice controls to keep exposures below a specified safety threshold; and offering medical exams to certain highly exposed workers.

Moldex® Solution

Where the guidelines call for a half mask, Moldex® half mask N95 respirators (disposable or reusable) may be used, in conjunction with the other elements of a comprehensive compliance program.

Click here to learn more about the Moldex respiratory solutions available for Silica exposure and for OSHA Fact Sheets covering Workers’ Exposure to Respirable Crystalline Silica: Final Rule Overview


FINAL RULE Federal Register

OSHA’s Final Rule to Protect Workers from Exposure to Respirable Crystalline Silica


General Industry and Maritime

Occupational Exposure to Respirable Crystalline Silica 29 C.F.R. § 1910.1053 – “Frequently Asked Questions for General Industry”

OSHA Assigned Protection Factors Publication 3352-02 2009

WARNING: No Moldex respirator may be used for or around Sandblasting Operations.

The information contained in this Tech Brief is dated and was accurate to the best of Moldex’s knowledge, on the date above. It is not meant to be comprehensive, nor is it intended to be used in place of the warning/use instructions that accompany Moldex respirators. Outside of the USA, check with all applicable and local government regulations.

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