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About face? A backlash to respirator quest
Are the proposed criteria too stringent?
Better-fitting respirators may not be the only outcome of proposed new criteria for N95s. Some critics predict frustration and confusion will be unintended consequences of the proposed rule.
At presstime for HEH, the National Institute for Occupational Safety and Health (NIOSH) was holding a second public hearing on proposed tough new criteria for "total inward leakage." It would require manufacturers to test their respirators on panels of 35 individuals and achieve a "total inward leakage" of only 1%. In other words, only 1% of a contaminant in ambient air would penetrate the respirator in a fit-test procedure.
To receive certification, at least 26 test subjects, or at least 74%, must be able to pass a fit within three tries. The respirator must fit at least one person in each "cell" or category that represents different facial features and sizes. Manufacturers also could market respirators to fit a specific niche, such as small facial dimensions. Twelve of 15 test subjects, or 80%, would need to pass in a niche designation.
Manufacturers would have three years to modify or phase out current respirators that don't meet the criteria.
The bottom line: With the new criteria, respirators would be more likely to fit right out of the box. While fit-testing would still be required, workers would have more protection if their employers didn't fit-test or if they were in an emergency situation that required them to use a respirator different from the one they had been fit-tested to wear.
"The requirements are to provide a minimum level of performance for these products," says Jonathan Szalajda, MSEP, MSIE, branch chief for Policy and Standards Development at NIOSH's National Personal Protective Technology Laboratory in Pittsburgh. "The goal is to have better respirators. The way to do that is through improved standards."
The proposed rule will benefit workers and employers by making it quicker and easier to conduct successful fit-tests, says AFL-CIO industrial hygienist Bill Kajola. "It would eliminate the low end of respirators that don't tend to fit workers very well," he says.
An end to fit-testing?
In the quest for better-fitting respirators, is NIOSH implying that fit-testing may not be necessary? NIOSH officials emphatically deny that. After all, the U.S. Occupational Safety and Health Administration (OSHA) requires employers to have a respiratory protection program and to fit-test employees who may be exposed to respiratory hazards.
Yet in an emergency situation, if a health care worker needed to use a respirator for which they were not fit-tested, they would still benefit from products that have better fit characteristics, NIOSH stated. They also would have a greater chance of passing a fit-test.
The problem of poorly fitting respirators came to the forefront during the H1N1 pandemic, when supply shortages forced hospitals to switch to different respirators. Earlier this year, California recalled millions of respirators that had been distributed from the state's stockpile when they failed most quantitative fit-tests.
The proposed NIOSH rule would take some of the burden of fit off the employer and onto the manufacturer. Yet there's a danger that the new requirements will lead to misimpression that respirators will be certified to fit out of the box, says Lisa Brosseau, ScD, CIH, associate professor in the School of Public Health at the University of Minnesota in Minneapolis.
"They're pushing the envelope of what we can possibly do. A panel test will not be able to promise [actual fit]," says Brosseau, who analyzed the NIOSH testing related to the Total Inward Leakage rule for the International Safety Equipment Association in Arlington, VA.
Although NIOSH updated the set of facial dimensions that represent the American population and greatly improved the respirator test panels, there are still inherent weaknesses, she says. For example, the "cells" of different facial dimensions don't take into account certain facial features, such as the size or shape of a person's nose.
Few Asians were included in the panel, and with the increase in the weight and size of the average American, the smallest "cells" were eliminated. However, some hospitals hire a significant number of Asian health care workers, and the predominantly female population tends to be smaller in stature than men working in industrial settings, Brosseau notes.
When you examine the fit-related data, "what becomes very clear is that there is a lot of variability between people," she says. That means fit-testing will always be an important function, she says.
"It's been our position consistently that fit-testing is something that has to be done on the individual user in the workplace, not as a part of the initial testing [of the product]," says Daniel Shipp, president of the ISEA.
Fewer respirators available?
The respirator you are currently using probably would not pass the proposed TIL criteria, and might have to either be redesigned or eliminated. That is the assertion of respirator manufacturers.
"[S]ome devices currently in use may not pass the new TIL limits even though they have been used effectively for years," Joann Kline, Regulatory Affairs Technical Leader for Kimberly-Clark Professional in Roswell, GA, said in written comments to NIOSH. "Significant design changes to these devices or complete market withdrawal would force users to find other models."
In its Federal Register notice, NIOSH said benchmark testing of 101 "half-mask air-purifying particulate respirators" – filtering facepiece respirators such as N95s and elastomeric respirators – indicated that about 30% would fail the proposed criteria.
However, a much higher proportion of the filtering facepiece respirators failed to meet the TIL of 100."They've created a set of criteria that, in my own opinion, is probably going to exclude 99% of the N95 respirators that exist right now. They are not going to pass," says Brosseau.
NIOSH is proposing a three-year phase-in period. After that time, manufacturers would be required to meet the TIL criteria to receive NIOSH certification.
The proposed requirement is actually in line with the level of fit OSHA requires in quantitative fit-testing, says Szalajda. Some respirators on the market should meet the proposed standard, he says.
Using a larger test panel – 100 test subjects rather than 35, for example – would lessen the likelihood that a well-fitting respirator would fail the new TIL criteria, suggests Mark Nicas, PhD, MPH, CIH, adjunct professor of environmental health sciences at the University of California-Berkeley. "You would have a better measurement of the true proportion of the population that the respirator fits," he says.
Manufacturers have asked NIOSH to allow all currently approved respirators to remain on the market indefinitely. Employers who are satisfied with their current respirators would then still have access to them, says Shipp. "If a respirator doesn't fit or if an employer cannot get a fit for workers with a particular kind of respirator, they're not going to buy that respirator," he says.
A new niche market?
The NIOSH proposal allows manufacturers to design a respirator for a particular subgroup and to market to that niche. This could mean a fundamental change in the way employers select respirators for their workers. A single model – even offered in different sizes – wouldn't be expected to fit all workers, says Szalajda.
"It's sort of like buying shoes. You don't just go out and buy a size 10 for everybody. You have to buy a variety of products with a variety of different characteristics," he says.
That raises questions about consumer information. How do you define a niche? How do you label the product? This goes beyond the typical labeling of small, medium, and large.
NIOSH says that manufacturers must provide a description of a subgroup that can be "reliably interpreted by users...Users must be provided sufficient information to allow them to self-identify. They might not effectively self-identify to match a manufacturer's intentions if provided only vague general descriptions of intended face shapes and characteristics."
NIOSH will need to develop some guidance for employers to help with respirator selection, says Szalajda.
Certification of respirators for a subgroup could benefit health care employers because a respirator could be designated specifically for women. There would still be quite a bit of variability, however, says Brosseau.
"Face size is not a predictor of fit. No one has ever found a good combination or size that tells you this respirator is going to fit this person well. That's why we recommend fit-testing," she says.
"Everybody would love to have the golden mask, to put it out there and say this will fit everybody," says Shipp. "I think it's clear that if the technology was there to do that it would have been done."
While NIOSH may alter its proposed rule in response to concerns raised by manufacturers, the agency is also under pressure to create criteria that will produce better-fitting respirators. Manufacturers will find a way to meet whatever criteria NIOSH ultimately sets, says Shipp.
"If the NIOSH requirements change, companies will do what is necessary to meet the NIOSH requirements," he says.
[Editor's note: The Federal Register notice and comments submitted about the proposed rule are available at www.cdc.gov/niosh/docket/nioshdocket0137.html.]