ORGIN: Moldex Technical Services Department
DATE: April 5, 2016


The Occupational Safety and Health Administration (OSHA) has 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. You must check with Federal and State agencies for compliance dates.

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.



Revised April 19, 2017

Important Update.

Employer obligations under the new Respirable Crystalline Silica standard for construction, found in Title 8, section 1532.3 of the California Code of Regulations, were scheduled to commence on June 23, 2017.

However, Cal/OSHA will not enforce those obligations until September 23, 2017. This synchronizes with federal OSHA’s plan to delay enforcement of their corresponding standard.

In contrast, unlike federal OSHA, Cal/OSHA’s new permissible exposure limit for respirable crystalline silica of 0.05 milligrams per cubic meter (0.05 mg/M3), found in Title 8 section 5155, Table AC-1, already went into effect on October 17, 2016. In addition, employers must continue to meet the requirements of Title 8 section 1530.1 to control employee exposures to dust created by operations conducted on concrete or masonry materials.

Per Title 8 section 5204, all employer obligations, except as otherwise stated in the standard, commence on June 23, 2018

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.


New guide will help small businesses comply with OSHA’s silica rule for general industry and maritime

OSHA has 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. Enforcement of the final rule in general industry and maritime is scheduled to begin June 23, 2018.

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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