Silica: It’s More Than Dust

Published: July 2, 2018

Silica: It’s More Than Dust

By Dylan Hipple, GSP, CHST

The inception of OSHA’s new rule on silica has raised a lot of question and concerns across all facets of construction. What is silica? Is it harmful? How am I exposed? What materials contain silica? Does all dust contain silica? How do I protect myself? How do I know the protection is working? These are just a few of the hundreds of questions associated with this topic being asked by workers across the United States. 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).

Why did we need new silica standards?

Th overall goal, like with any other safety standard, is to protect workers. The dangers of silica are not a new discovery. Over 80 years ago, the U.S Secretary of Labor Francis Perkins first brought up the issue of the dangers of silica exposure. A meeting was held to determine ways to protect employees from the dangers of silica. The PEL that was put into practice was more than 40 years old before OSHA’s final rule on silica began in September of 2017. The original PEL was determined by research compiled in the 1960’s and did not reflect other dangers that have since been discovered. Research has since been conducted and determined that workers were in fact contracting cancer and lung diseases at the PEL that was allowed by OSHA until recently. The technology to protect workers has been and still is readily available to employers to protect the employees that work with crystalline silica.

OSHA’s new Silica Rule

As stated above, OSHA has been aware of the hazards of silica for a number of years. The major changes to the standard are regarding the Permissible Exposure Limit (PEL). There has been a drastic change in the PEL; from 250 mg/m3 to 50 mg/m3, with an action level of 25 mg/m3. Along with the new PEL, OSHA has also established other employer requirements that will be outlined below.

What is Silica?

Crystalline silica is a common mineral that can be found in everyday life. Certain trades may be exposed to silica more than others, but most trades will find it somewhere in their workplace. Some of the most common occurrences of silica arise in roads, buildings, and sidewalks. Crystalline silica is a common component of materials such as concrete, brick, block, mortar, stone, rock, and sand. The exposures occur when these materials are disturbed in some way. Disturbance may occur through common operations such as cutting, sawing, drilling, crushing, hammering, or other methods typically used in construction.

Employer Requirements

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.
Medical Surveillance Programs

One significant requirement of the new rule: employers must provide medical exams to monitor exposed workers and give them information about their lung health. The exams must be made available to workers every three years. The exam consists of the following:

A medical and work history that emphasizes past, present, and anticipated exposure to respirable crystalline silica, dust, and other agents affecting the respiratory system; any history of respiratory system dysfunction (signs and symptoms of respiratory disease such as shortness of breath, cough, wheezing, etc.); history of tuberculosis; and smoking status and history;
A physical examination with special emphasis on the respiratory system;
A chest X-ray with interpretation by a certified B-reader;
A pulmonary function test administered by a spirometry technician with a current certificate from a NIOSH-approved spirometry course;
Testing for latent tuberculosis infection; and
Any other tests deemed appropriate by the medical professional.

OSHA’s Table 1

The simplest and most common method of compliance with the new silica rule is the use of Table 1. OSHA developed Table 1 as an easy way for construction workers to comply with the new standard and to protect worker exposure. Table 1 lists eighteen common construction activities that involve exposure to crystalline silica. Each activity lays out guidelines to follow to be in compliance. Table 1 mainly utilizes two methods to reduce silica exposure: Wet method and vacuums.

Wet Methods/Vacuums

Almost all silica disturbing activities can be reduced or eliminated with the use of water or HEPA vacuum systems. When using the wet method (water) to reduce silica dust, the equipment or tool must use an integrated water delivery system developed by the manufacturer. That means that spraying a hose as an employee saw cuts concrete is not in compliance with Table 1. Vacuum’s must be HEPA to capture the harmful silica particulates in the air.

Tool Adaptions

In lieu of the new silica standard release, almost all tool manufacturer’s have made water and vacuum attachments for their tools. Manufacturer’s that are making silica compliant tools/equipment available include; Hilti, Milwaukee, DeWalt, Bosch, etc. Some of the attachments include hollow drill bits with vacuum attachments, cordless tools with built in vacuums, integrated water delivery at the point of contact, and others.

Exposure Control Plans

Employers who fall into the requirements of the new standards must develop and implement written exposure control plans for all activities that expose employees to crystalline silica. Written Exposure Control Plan’s (ECP) identify specific workplace activities that involve silica and provide a method for reducing or eliminating exposure. These exposures are reduced or eliminated through engineering controls, work practices, housekeeping methods and restricting access to areas of high silica exposure. The plans help employers improve exposure control by identifying the tasks that require action. The following are the requirements of each written exposure control plan:

The plan must include a description of workplace tasks involving exposures to respirable crystalline silica.
The plan must include a description of engineering controls, work practices, and respiratory protection used to limit employee exposure to respirable crystalline silica for each task.
The plan must include a description of the housekeeping methods used to limit employee exposure to respirable crystalline silica.
The plan must include a description of the procedures used to restrict access to work areas, when necessary, to limit the number of employees exposed to respirable crystalline silica and the levels to which they are exposed, including exposures generated by other employers or self-employed workers.

References:

OSHA CFR 1926.1153

OSHA Small Entity Compliance Guide for the Respirable Crystalline Silica Standard for Construction