Recently I have received numerous emails and phone calls regarding respiratory air-filtering masks rated for arc flash. I’m sure everyone reading this, no matter what country you’re in, is aware why that’s the case: the COVID-19 pandemic.
If you are a regular reader, you know it is my methodology to address topics by first citing the related safety standards in effect and then discussing the issue from a practical perspective typically related to the utility industry. This time is no different – for the most part.
Initially, the use of masks during the pandemic was limited as effective respiratory protection and still is for the public per the Centers for Disease Control and Prevention. As far as OSHA was concerned regarding workplaces, the only approved mask was the NIOSH-approved N95 filtering facepiece respirator (FFR). The N95 rating means that the mask meets the criteria for effective filtering of airborne particulates and moisture at 95%. The rating system also was established by NIOSH. It is important to understand that the N95 rating is based on the assumption that the masks are utilized by trained users meeting the OSHA respiratory protection worker training and fit-testing standard, which also can require a medical evaluation of the user.
As a result, no authority in government recommended public use, later adding that N95 masks needed to be available to trained health-care and emergency personnel who could put them to their best use. It also is important to understand that the N95 mask was not tested as a viral barrier; it was recognized as effective at preventing the spread of an individual’s exhaled, airborne droplets that could contain the SARS-CoV-2 virus that causes COVID-19.
At the time of this writing, OSHA is still recommending engineering, administrative and procedural changes to limit the need for N95 respirators in an effort to preserve them for the health-care industry.
With that knowledge in place, let’s move forward. In our industrial environment, even the N95 mask has limited protection for the user. The mask is more effective at capturing water droplets in the breath of an infected person who wears it. The CDC is now recommending that members of the public use simple cloth face coverings when in a public setting to slow the spread of the coronavirus. Doing so will help prevent people who may unknowingly have the virus from transmitting it to others.
Based on the above, we know that the FFR has limited use and that cloth coverings, such as a neckerchief, are recognized as an effective alternative. Now, let’s get to an analysis of the exposure. Arc flash assessments drive the level of protection based on distance and arc energy. It is fair to assume that an arc flash with the energy to ignite a face covering likely means you should be wearing an arc-rated face shield and a balaclava. From a practical perspective, if you are wearing a face shield, the energy passing the shield would not likely ignite a face covering made from cotton or another natural-fiber cloth.
A Valuable Technical Treatment
For the rest of this installment of “Train the Trainer 101,” I decided to turn to Hugh Hoagland, an industry-recognized source of information and guidance for all things related to arc flash. He is a senior consultant at ArcWear (www.arcwear.com) and a senior partner at e-Hazard (www.e-hazard.com), both recognized authorities in the utility industry. Hugh penned the following valuable technical treatment of testing performed by his companies, and I decided it was worth publishing here in its entirety.
Hugh Hoagland: Did I ever think I would write an article or a paper on this subject? Absolutely not. Fortunately, over the past 25 years of arc testing, I have come across some odd situations that required electrical workers to wear respirators. The first testing was for a mining association; the second was done at U.S. Department of Energy sites that contained radioactive beryllium dust exposures; and the most recent was this past summer when the state of California instituted guidance that utility workers in wildland fire exposures need to have proper respiratory protection from smoke. These workers, who could be disconnecting power to prevent further damage, are what we now refer to as “essential workers.” The ways in which we protect them, as best we can, are critical.
There is no ASTM, IEC or NFPA standard for testing respirators for arc flash. There is an NFPA standard for firefighters’ self-contained breathing apparatuses, but it does not cover arc flash. An e-Hazard blog found at www.e-hazard.com/blog/covid/ contains help on the COVID-19 crisis as it relates to electrical workers, with assistance from publicly available ArcWear test data. The blog provides the public test reports and a peer-reviewed paper that support using firefighter respirators as non-contributory in an arc flash to certain levels, as well as reports showing a low risk for using common respirators, including N95 masks, under a face shield or hood at certain levels.
The ASTM F18 committee is attempting to address concerns by providing an easier labeling requirement for the cloth face coverings recommended by both the CDC and a special OSHA COVID-19 document indirectly recommending CDC guidelines, if needed, in work settings. The ASTM F18 committee asked David Wallis – who is now an electrical safety consultant after retiring from OSHA – for his opinion. Wallis said, “I can give you general industry cites for requirements prohibiting ignitable face masks under certain conditions:
“§1910.269(l)(8)(iii) prohibits ‘clothing that could melt onto his or her skin or that could ignite and continue to burn when exposed to flames or the [employer's estimated] heat energy.’ The note following that provision generally prohibits clothing made from acetate, nylon, polyester, rayon and polypropylene, either alone or in blends. Consequently, any face mask, at a minimum, would generally need to be made from all-natural fabrics regardless of the presence of any arc-rated head and face protection.
“§1910.269(l)(8)(iv) requires the outer layer of clothing worn by an employee to be flame resistant if the employee is exposed to contact with energized parts operating at more than 600 volts or if two other less likely conditions are present. There is an exception for clothing covered by an exception to paragraph (l)(8)(v), but none of those exceptions would apply to face masks. Thus, when there is no arc-rated protection, any face covering would generally need to be flame resistant.
“Subpart V contains equivalent requirements. The standards don't require face masks to be arc rated as long as any required arc-rated protection is otherwise provided, but the masks would typically need to be FR or worn under arc-rated protection if made from non-prohibited fabrics.”
So, flame-resistant cloth face coverings, or FR CFCs, meeting ASTM F1506 would meet the OSHA requirements and CDC recommendations. A proposed change balloted now in ASTM F1506 would allow smaller labels for these items. This is expected to be final in about 60 days or so.
For non-utility work, NFPA 70E states the following: “130.7(C)(12) under the title Clothing and Other Apparel Not Permitted: Clothing and other apparel (such as hard hat liners and hair nets) made from materials that do not meet the requirements of 130.7(C)(11) regarding melting or made from materials that do not meet the flammability requirements shall not be permitted to be worn …
“Exception No. 2: Where the work to be performed inside the arc flash boundary exposes the worker to multiple hazards, such as airborne contaminants, and the risk assessment identifies that the level of protection is adequate to address the arc flash hazard [italics added], non-arc-rated PPE shall be permitted.” As long as these vital devices are covered, it is likely they will comply with both OSHA and NFPA requirements. Using FR CFCs that are compliant with ASTM F1506 will assure it.
So, every industry has options with the wording of current regulations to meet the needs of workers with little risk of creating another hazard in a potential arc flash.
Cloth face coverings assist in reducing your chances of spreading the coronavirus, if you are infected, and may reduce risk of contracting the virus, but only a true particulate respirator can offer complete protection. ArcWear testing indicates that wearing N95 masks under face shields, balaclavas and hoods can meet the requirement for complete protection, but there is some risk of ignition in certain conditions. Many utilities are using face shields and/or balaclavas, cloth face coverings with an arc rating, and true respirators to protect their workers and meet OSHA requirements as well as the CDC guidelines. All we are doing should be to keep workers safer. You are essential. Thank you all for your service!
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