Silica Success

| OSHA

Written by: Dr. Adam Marty, USF SafetyFlorida Safety & Health Consultant

The Occupational Safety and Health Administration (OSHA) has been enforcing provisions of the new respirable crystalline silica standards for several months now, one for construction and one for general industry and maritime.  The new standards have set a permissible exposure limit (PEL) of 50 micrograms per cubic meter (ug/m3) of air and an action level of 25 ug/m3.  The new standards are similar in that they both contain provisions for engineering and work practice controls, establishment of an exposure control plan, respiratory protection, housekeeping, medical surveillance, communication of respirable crystalline silica hazards, and recordkeeping. However, they differ in that general industry and maritime must perform an exposure assessment, whereas, the construction industry may use specified exposure control methods listed in table 1 of the construction standard.   The standards have also set forth specific requirements for exposures at or above the PEL and for exposures at or above the action level but below the PEL, including periodic exposure monitoring.

OSHA estimates that once the effects of the new rules are fully realized, they will prevent more than 600 silica-related deaths and more than 900 new silicosis cases per year.  Companies that implement an effective silica control program can expect better workplace morale, a more favorable image and reputation, potential savings in workers’ compensation insurance, and potential savings from not being required to implement or maintain costly programs associated with high silica exposures. SafetyFlorida Consultation has already begun to see several of their client companies enjoying successes in reducing their employee exposures including saving precious resources, time and money.

Two of SafetyFlorida’s client companies, in particular, come to mind regarding the implementation of the new silica standards.  One company is a stone countertop manufacturer and the other is a dry concrete materials manufacturer.  The dry concrete materials manufacturer mixes and bags dry materials.  The process machinery is enclosed and ventilated, the ventilated air filtered through a baghouse, and the filtered air discharged into the work area.  Since a baghouse is designed to filter medium to large sized particles, a haze was observable in the discharged air during the first consultation site visit. Also, dry concrete materials and dusts were notable on the floors and horizontal surfaces.  Foot and powered industrial truck traffic generated noticeable airborne dusts as did any gust of wind that blew through the building.  Employee exposures were measured 3.7 times over the new silica PEL during a consultation in November 2016.  The company followed SafetyFlorida Consultation recommendations to reduce the exposures including consulting an industrial ventilation professional, installing HEPA filters on the baghouse discharge, and performing extensive and ongoing housekeeping.  Two years later, the dry concrete materials manufacturer had reduced their employee exposure levels to below the new silica action level.

The second company, a stone countertop manufacturer, processes large stone slabs into countertops and other home furnishings.  Much of the initial stone processing is done using machines with integrated water delivery systems.  Some of the finer stone work was done using hand tools with integrated water delivery or was done using a squirt bottle to deliver a water spray.  However, some hand work was done dry.  Cut stone dusts were also noticeable on the floors and horizontal surfaces.  As was the case in the above example, foot and powered industrial truck traffic also generated noticeable airborne dusts as did any gust of wind that blew through the building.  Employee exposures were measured 1.3 times over the new silica PEL during a consultation in May 2017.  The company followed SafetyFlorida Consultation recommendations to reduce the exposures including eliminating all dry work, purchasing additional hand tools with integrated water delivery, and performing extensive and routine housekeeping.  One year after the first consultation, the stone countertop manufacturer had reduced their employee exposure levels to below the new silica action level.

The successes of these two companies did not come without some initial investment in resources.  These companies purchased some new equipment, took time to properly clean up silica-containing dusts, and performed additional training.  However, these companies were not required to invest resources into establishing or maintaining the mandatory programs that would have been required if employee exposures to silica remained above the new OSHA limits. The companies did not have to establish a medical surveillance program, nor were they required to maintain a respiratory protection program.  Furthermore, these companies were not required to conduct periodic air monitoring unless a change occurs that could increase exposures above the new limits.

This is not to say that these companies still do not have to comply with some aspects of the new standards.  These companies must still maintain a written exposure control plan, communicate respirable crystalline silica hazards to employees, maintain good housekeeping practices, retain certain records, and continue to sustain the engineering and work practice controls currently used.  In fact, all companies where occupational exposures to respirable crystalline silica occur should have already implemented aspects of the new silica standards.

Effective engineering and work practice controls are effective and the best methods to reduce employee exposures, as are routine housekeeping practices.  The two companies previously mentioned are good examples of companies that implemented an effective silica control program to reduce silica exposures.  As a result, these companies are in compliance with the new silica standards.  Of utmost importance though is that the owners and managers of these companies should take pride in providing their employees with a safe and healthy workplace.  If there are questions about the new silica standards or if assistance is needed in conducting an exposure assessment, please contact USF SafetyFlorida Consultation, http://www.usfsafetyflorida.com/, for a free review and evaluation.

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