Page 23 - Occupational Health & Safety, September 2018

INDUSTRIAL HYGIENE
Three Dangerous Misconceptions Surrounding OSHA’s Silica Dust Standard for General Industry
On June 23, most provisions of OSHA’s silica standard for general industry became enforceable. Many employers still have a long way to go to achieve full compliance.
BY STEPHEN WATKINSAlthough the dangers of respirable crystal- line silica have been known for more than 80 years,1 silica dust has only recently be- gun to be recognized as the major health hazard it is. In fact, silica is now frequently referred to
in safety circles as “the new asbestos.”
However, despite the fact that the risks are well
known, many employers still haven’t taken the steps required for compliance. These steps include measur- ing worker exposure, implementing controls to keep exposure below the specified limits, and verifying that those controls work.
In talking with our customers as well as outside safety consultants, we’ve learned that one reason many general industry employers still haven’t complied is that they don’t entirely understand the new standard and how it applies to them. This lack of understand- ing has led them to develop misconceptions that can be dangerous for everyone involved — dangerous for employees who aren’t being adequately protected from silica dust and dangerous for employers who aren’t prepared for inspectors to knock on the door. Let’s clear up a few of these misconceptions.
“I’m aware of all of the silica dust hazards in my operations.”
In an interview earlier this year, safety consultant Abby Ferri told Nilfisk that she’s had several experi- ences where she was called in to perform silica safety training, but when she arrived at the facility, she real- ized that the employer didn’t have a clear picture of what activities were generating exposures and which workers were exposed.2 This is because the employers hadn’t yet taken the first step of examining their op- erations and performing exposure assessments.
The standard provides two options for an exposure assessment:3
1. Performance option. Employers can measure the 8-hour time-weighted average (TWA) expo- sure for each employee using either air monitoring data or objective data. Objective data can be from industry-wide surveys or calculations as long as it “reflect[s] workplace conditions closely resembling or with a higher exposure potential than the pro- cesses, types of material, control methods, work practices, and environmental conditions in the em-
ployer’s current operations.”
2. Scheduled monitoring option. Employers can
perform initial monitoring to measure the 8-hour (TWA) for each employee using “personal breathing zone air samples that reflect the exposures of em- ployees on each shift, for each job classification, in each work area.” This initial monitoring is followed by subsequent monitoring every three or six months, depending on the result of the initial test. The sched- uled monitoring option also provides a representa- tive sampling method for groups of employees who all perform the same tasks on the same shift and in the same place.
Regardless of which option you choose, the sam- pling will most likely need to be done by an industrial hygienist using personal sampling pumps fitted to each employee.4 After the samples are collected, they need to be sent for laboratory analysis. Appendix A of the standard specifies procedures for analyzing the air samples.
Until you follow these steps, it’s impossible for you to have an accurate picture of the silica dust hazards that exist in your operations. Without this full picture, you can’t guarantee that any controls you implement will mitigate your employees’ safety risks.
“I just need to provide respirators.”
The new general industry standard sets the permis- sible exposure limit (PEL) for silica at 50 μg/m3, cal- culated as an 8-hour TWA. That’s roughly half of the previous PEL. This drastic reduction is more than
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SEPTEMBER 2018 | Occupational Health & Safety 19
NILFISK INC. INDUSTRIAL VACUUM DIVISION