In the opening session of the workshop, Richard Metzler, a retired senior scientist at the National Personal Protective Technology Laboratory (NPPTL) at the National Institute for Occupational Safety and Health (NIOSH), explored how the assessment and approval of respiratory protective devices (RPDs) have evolved over the past century to meet the needs of occupational users. He discussed how lessons learned from that use can inform planning for imminent and future needs regarding the occupational and public use of respirators. The session was moderated by workshop planning committee member Melissa McDiarmid, a professor of medicine, epidemiology, and public health at the University of Maryland School of Medicine.
Conformity assessment (CA) activities are the vital link between standards and products, services, processes, systems, personnel qualifications, and organizations, Metzler said.1 He defined CA as “the demonstration that specified requirements relating to a product, process, system, person, or body are fulfilled.”2 CA can include suppliers’ declarations of conformity and independent certifications. Suppliers’ declarations of conformity
1 More information about conformity assessment activities is available from https://www.standardsportal.org/usa_en/conformity_assessment/conformity_assessment.aspx (accessed September 16, 2020).
are first-party statements of the ability to conform to specified standards. Certifications are always independent, third-party declarations of conformance, and they can include sampling and testing, inspections, management system assessment, and product quality control. Additional components of CA include accreditation of the competencies of those performing the certification activities and recognition of the accreditation program’s capability.
Metzler explained that these CA activities are outlined in the National Technology Transfer and Advancement Act.3 Signed into law in 1996, this legislation was designed to promote economic, environmental, and social well-being and to bring technology and industrial innovation to the marketplace. The National Institute of Standards and Technology is responsible for coordinating federal, state, and local standards and CAs. The American National Standards Institute (ANSI), a private, not-for-profit organization, coordinates the U.S. voluntary standards and CA system. ANSI facilitates the development of American national standards by accrediting more than 240 standards development organizations, such as ASTM International, the National Fire Protection Association, and the International Symposium on Computer Architecture.
Effective Conformity Assessment for Respiratory Protective Devices
RPD requirements are typically defined in American national standards developed by ANSI-accredited standards development organizations, Metzler said, but they may also be included in contracts and purchase agreements. Requirements for RPDs include design, performance, quality assurance and control, reliability, labeling, caution limitations and restrictions of use, and user instructions. Metzler said that the risk of hazardous exposure from use of nonconforming products is critical for driving CA activities for personal protective technologies; the specified standards should be effective in reducing the risk of exposure to safe levels. The National Academies of Sciences, Engineering, and Medicine (the National Academies) have studied and made recommendations for effective CA for personal protective equipment (PPE) and RPDs, Metzler said. In 1995, the National Research Council (NRC) recommended that government agencies retain oversight responsibility for critical regulatory and procurement standards in the area of public health, safety, environment, and national security (NRC, 1995). The same publication also recommended that the private sector perform assessment activities for conformance to standards, with the government acting only in an oversight capacity. In 2008, in a review
3 More information about the National Technology Transfer and Advancement Act is available from https://www.nist.gov/standardsgov/national-technology-transfer-and-advancement-act-1995 (accessed September 16, 2020).
of research programs at NIOSH, an NRC and Institute of Medicine (IOM) committee recommended that NIOSH, in collaboration with a variety of organizations, should assess the certification mechanisms needed to ensure the efficacy of all types of personal protective technologies (NRC and IOM, 2008). Additionally, in 2011 the IOM recommended that NIOSH’s NPPTL lead an effort to develop and implement a comprehensive, tiered risk-based framework for the classification and CA of personal protective technologies for specific applications (IOM, 2011a). From this work and in collaboration with private-sector organizations, NIOSH published a national CA framework for PPE in 2018 (NIOSH, 2017).
Metzler said that the CA infrastructure in the United States is sufficiently robust to support risk-based CA for PPE. To accomplish this he suggested using private-sector CA programs with centralized oversight, with the NIOSH-developed national framework for PPE CA applied to ensure the effectiveness of the CA program. He noted that the current infrastructure is market-driven and decentralized, having been shaped over the past century by major events including two world wars. As it evolved over time, the CA infrastructure has focused on appropriate standards and conformance for the acquisition of military equipment and on industries such as railroads, electrical power, fire service and prevention, and insurance. Global trade has also been a major factor in CA infrastructure, he added. Today, there are thousands of CA programs with different types of activities and varying levels of independence and robustness that depend upon the particular program’s objectives. Metzler said that the regulatory system for PPE is decentralized—for example, the range of PPE approved by NIOSH includes respirators used for occupational use, body armor for the Department of Justice (DOJ), fire service products for the National Fire Protection Association (NFPA), personal flotation devices for the U.S. Coast Guard, and helmets for the Snell Foundation but does not include cloth masks or face coverings. As NIOSH already provides oversight for respirator approvals, Metzler suggested that the current infrastructure could support an update to NIOSH’s existing program for RPDs and additional PPE. However, he added that the current infrastructure lacks a centralized authority to provide oversight of nontraditional and public uses of RPDs.
Metzler briefly traced the history of the approval process for RPDs (Spelce et al., 2019). Approval programs were established in the early 1900s, with the United States Bureau of Mines (USBM) making the first respirator certification program in 1919. In establishing a CA program, USBM indicated that certificates of approval should be based on the concept of permissibility, meaning that the product is safe for the intended use.
This concept of permissibility was extended beyond respirators and applied to all mining products, including equipment such as explosion-proof enclosures, explosives, and fire-resistant conveyor belts. USBM subsequently established the basic health and safety standards for all approved respirators: They must give adequate protection for intended use, be reasonably comfortable and convenient to wear, provide acceptable protection for a suitable period, and be constructed of durable materials. These approval requirements were linked to hazard classification and uses, with varying requirements for different respirator types. Metzler said that this approach is challenging in situations where the knowledge of a hazard is evolving or the technologies are advancing.
“Conformity assessment is necessary to safeguard personal protection, but it’s not sufficient to ensure intended protection,” Metzler emphasized. He offered four considerations related to ensuring adequate protections for users. First, a respiratory protection program is vital to ensure proper product selection, use, and maintenance of RPDs. Respiratory protection program standards were revised by different organizations a total of seven times between 1938 and 2019, he said. The Occupational Safety and Health Administration (OSHA) implemented Respiratory Protection Standard 1910.1344 in 1971, and NIOSH began administering respirator quality control provisions in 1972 via the federal regulation 30 CFR 11.5 A major lesson learned from the past century, Metzler said, is that a respiratory protection program is necessary and should not be “short-circuited” for public protection.
The second consideration, Metzler said, is that for RPDs “a certification does not necessarily equal an approval.” Private-sector accredited certification organizations make independent third-party declarations of conformance to specified standards. However, they do not ensure that the specified standards are appropriate to meet the intended uses and exposures to specific hazards. Furthermore, the standards used in the private sector might not adequately describe the hazards or the limitations of use for conforming products. Until these aspects are integrated into the process, Metzler said, private-sector certification will not be not equivalent to NIOSH approval. Metzler’s third point was that U.S. law requires NIOSH, when developing new mandatory regulations or standards for respirators, to not reduce the protection of existing standards. This is a challenging requirement that necessitates substantial consideration from NIOSH every
4 More information about Respiratory Protection Standard 1910.134 is available from https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.134 (accessed September 16, 2020).
5 More information about federal regulation 30 CFR 11 is available from https://www.govinfo.gov/content/pkg/FR-1995-06-08/html/95-13286.htm (accessed September 16, 2020).
time new regulations are developed. Additionally, NIOSH must meet the obligations outlined in the Regulatory Flexibility Act,6 which include assessing the need for the regulation, identifying alternatives, and determining whether the regulation is designed to achieve the agency’s objectives in the most cost-effective manner. NIOSH also facilitates the use of performance standards. Metzler suggested that these standards could also be applied to CA programs for protecting the private sector.
Finally, a fourth consideration for protecting users is centralized CA program oversight to help ensure effectiveness, Metzler said. This would address issues such as evolving hazards, technological advancements, and updating requirements or revising standards. It would also make determinations regarding “grandfather periods,” or periods of transition from previous standards to a new standards. A centralized program could resolve issues regarding nonconforming or counterfeit products and ensure that CA process evaluations are effective, he added.
Metzler explained that CA of RPDs is a component of a broader integrated system of requirements to ensure protections in the United States; this broader system includes national laws and regulations, the industrial hygiene infrastructure, the standardization infrastructure, the broader CA infrastructure, and federal and private research. Metzler suggested that a national strategy is needed for nontraditional RPD users, including the general public, a population for which there is no centralized, recognized authority currently providing oversight. In contrast, he said, centralized oversight of RPD conformance with standards for various occupations is provided by OSHA, the Mine Safety and Health Administration (MSHA), and the Department of Energy (DOE). For nontraditional RPD users, there are multiple agencies that have some form of jurisdiction, including NIOSH, the Food and Drug Administration (FDA), the Consumer Product Safety Commission, and now the Department of Homeland Security. The absence of centralized, secure, and clearly identified leadership can lead to inconsistencies, he said, adding that this is now evident in issues related to the national implementation of face coverings as a form of source control during the coronavirus disease 2019 (COVID-19) pandemic.7
Metzler emphasized that a public protection system with recognized
6 More information about the Regulatory Flexibility Act is available from https://www.govinfo.gov/content/pkg/STATUTE-94/pdf/STATUTE-94-Pg1164.pdf (accessed September 16, 2020).
administrative authorities—mirroring the system in place for occupational safety and health—could integrate safety and health and CA risk-based requirements to ensure that PPE wearers are properly protected. This could be accomplished by integrating the safety and health requirements for these users with CA risk-based requirements, he suggested. Specifically, a nationally recognized authority could:
- Establish and maintain protection requirements based on hazards and risks;
- Investigate nonconformance and fraudulent CA declarations and remove nonconforming products;
- Inform and provide the public with critical guidance when new or evolving hazards arise; and
- Update processes and requirements to address new or evolving hazards, advances in technologies, and revised or new national consensus standards.
Metzler concluded that the absence of these oversight functions weakens protection and reduces confidence in PPE conformance declarations; he said that Congress is best suited to act to fill this gap by identifying a centralized authority.
Contrasting Certifications and Approvals
Planning committee member Robert Harrison of the University of California, San Francisco, asked for clarification about the differences among CA, certification, and approval. Metzler said that CA involves a large number of varied activities and that the supplier of the product can perform these. When it is the supplier conducting CA activities and declaring that the standards are met, the user must decide (1) whether this first-party declaration of conformity is an effective declaration and (2) whether the appropriate standards have indeed been met. Certification, which is one of many types of CA activities, requires a declaration from an independent third party that a product conforms to the standard. Metzler added that an evaluation conducted by an independent group allows for greater user confidence. There are a number of private-sector organizations that issue third-party certifications for a variety of products, such as the Safety Equipment Institute and UL (Underwriters Laboratories Inc.).
Metzler explained that approval is a process that begins with the identification of a hazard, followed by a determination of the appropriate standards to address that hazard and then an evaluation of the product to ensure
that the product conforms to standards. The approval contains clearly identified hazards the product protects against, the product’s intended use, and a variety of standards that the product would have to meet to ensure the wearer of that equipment is safe. In contrast, certifications do not necessary identify the hazard a product protects against. While a certification declares that a product conforms to a specified standard, it does not necessary link back to the hazard—a step that is required for approvals. Furthermore, approvals are a regulatory issue. For example, OSHA rules and regulations require a NIOSH-approved respirator for occupational uses, and NIOSH controls the certificate of approval. If NIOSH finds that a product is not conforming and the manufacturer’s system cannot produce conforming products, then NIOSH can take away the certificate of approval and void the approval that it previously granted. Metzler said that NIOSH currently issues approvals for occupational-use respirators, but respirators used in mine emergency applications require joint approval from NIOSH and MSHA. For all other occupationally used respirators, NIOSH conducts CA activities and issues approvals independently. NIOSH does not currently use accredited third-party certifiers or laboratories in conducting its approval program, Metzler said.
Challenges to Nontraditional User Respirator Approval
McDiarmid asked about the barriers that might be encountered in extending the “traditional”8 NIOSH approval process for occupational use products to products for nontraditional users. For example, there may be insufficient information about risk assessment for nontraditional users, including risks from the very hazards the products are designed to protect against. One barrier, Metzler answered, is the constant tension in the United States between personal freedom and community protection. He predicted that there would be resistance to any additional federal coordination or oversight over broad CA for respirators that might be used by the public. Thus, he suggested adding oversight to provide coordination rather than directly performing approval activities for products used by the public. He added that work should be carried out by the private-sector CA system, as NRC recommended in 1995 (NRC, 1995). Metzler emphasized the need for a central federal organization with recognized authority to analyze data and ensure that both decentralized certification programs and self-declaration-type programs are achieving their objectives. When objectives are not met, he said, NIOSH could perform assessments and identify proper corrective action to warn the public of concerns.
8 A participant commented that the National Institute of Standards and Technology no longer uses the word “traditional” in its communication or publications.
McDiarmid asked Metzler to comment on the difference between nontraditional occupational users and public users. Metzler said that the lessons learned from the first half of the 20th century illustrate the negative ramifications of operating without a respiratory protection program that includes the elements of hazard identification, respirator selection, training, and respirator certification or approval. During that period, researchers found that mineworkers were overexposed to some hazards despite using USBM-approved respirators. Metzler said that even though the respirators conformed to standards set by USBM, they did not deliver the intended protection because they were used improperly. He added that it is unfortunate that some people believe that using conforming respirators makes a respiratory protection program for the public unnecessary, because history indicates otherwise.
Planning committee member Howard Cohen of the Yale School of Medicine said that he gained an understanding from the opening session of the workshop that first a hazard should be identified, then the identified hazard should result in a standard, and finally, CA should be developed for that standard. However, he said, the traditional understanding is that standards relate to products, rather than to the hazard. Furthermore, he proposed that Metzler put forward two standards: a standard of care for using the device and a standard for the device itself. Cohen suggested that the standard of care for using the device should be clarified for nontraditional workers and the public. A nontraditional user might assume that because a respirator is an N95 NIOSH-approved respirator, a person is sufficiently protected when using it. However, protection may depend on how the device is used. Cohen asked Metzler whether a central authority should be responsible for communicating to nontraditional users that a device will not necessarily offer protection unless it is used correctly.
Metzler suggested that a centralized authority could help eliminate inconsistencies in implementation in the United States; he also clarified his use of the word “authority.” He explained that multiple authorities can provide needed recommendations and continuity within a program (e.g., DOJ’s involvement with body armor approval and NFPA’s oversight of fire service equipment). Metzler said he was involved in developing 42 CFR 84 (the current standard for RPDs) and that during that process the 1972 requirement in 30 CFR 11 that called for a respiratory protection program was removed. The requirement was removed because OSHA, MSHA, DOE, and other agencies were already using established national consensus-based respiratory protection program requirements or regulations. Metzler expressed some regret about that decision in hindsight, explaining that having a central respiratory protection program connected with approval could help reinforce the idea that protection is not conferred simply by conformance but rather that the protection program coupled with the RPD CA confers protection.
Role of Agencies and Organizations in Imposing Additional Requirements for RPDs
A participant asked Metzler to comment on NIOSH’s statement that the NIOSH RPD approval does not apply to nuclear and radiologic hazards. Metzler replied that he would let the representatives of NIOSH address specific questions about approvals and instead commented on the general process for respirator approvals in the United States. Typically, he said, NIOSH has basic requirements for respirator approval, and federal agencies may impose additional requirements for respirator use within their jurisdictions. For example, DOE may have additional requirements on equipment used at chemical waste storage sites that extend beyond NIOSH requirements. Metzler said he is not under the impression that NIOSH has eliminated respirator use against radiologic hazards from its program. The current 42 CFR 84 requirement for particulate respirators applies to all particulates; NIOSH uses a worst-case aerosol test under extreme conditions to approve the particulate filtering component of the respirator. Metzler said that he would not eliminate that step and noted that federal agencies can add further requirements. He also pointed out that organizations need not be federal agencies to add requirements—for example, NFPA outlines requirements for self-contained breathing apparatus for specific uses in the fire service. Metzler added that, typically, NIOSH would approve a self-contained breathing apparatus and then NFPA also would have the product certified by a certification organization to ensure that the specific NFPA requirements are met.
Role of Federal Agencies in Public Respiratory Protection
Planning committee member John Balmes of the University of California, San Francisco, noted NIOSH’s central role in CA, certification, and approval of respirators for occupational users and remarked that multiple agencies are currently involved in respiratory protection for the public, including FDA, the Environmental Protection Agency, and the Centers for Disease Control and Prevention. Balmes asked Metzler to comment on the involvement of multiple agencies that may not be coordinating with one another. Metzler responded, “It’s always difficult to have large organizations on exactly the same page” due to differences of opinion regarding a hazard or about the effective use of a product. Until a sufficient amount of research and data are available to clearly identify the appropriate direction, legitimate differences among organizations can make it difficult to coordinate, he added. For example, in the case of facial coverings or respirators being worn in response to COVID-19 outbreaks, the public was first told that these devices and coverings should not be worn and later told that they should be worn. He cited discussions
about how much respiratory protection face coverings offer. In the case of the COVID-19 pandemic, information about the hazard is evolving, and recommendations are changing to appropriately respond to new information. In addition, the lack of a central authority to provide single answers also plays a role. Metzler said it is extremely important that any approved or certified product—and even any product self-declared to meet a standard—provides cautions, limitations, and restrictions of use, which are as important as the product’s intended use.
Role of NIOSH in Approving Respirators for Use in Health Care Settings
A participant asked about FDA’s role in the approval processes described by Metzler. Maryann D’Alessandro, the director of the NPPTL at NIOSH, explained that NIOSH approves all respirators that are used in occupational settings. In addition to NIOSH’s approval requirements, FDA requires that N95 respirators used in health care settings meet standards for fluid resistance, biocompatibility, and flammability. Prior to 2018, FDA cleared NIOSH-approved respirators for these additional protections. However, in 2018 a memorandum of understanding between NIOSH and FDA established a coordinated effort between NIOSH and FDA and resulted in NIOSH assuming the role of approving N95 respirators for use in health care per FDA requirements.9
A participant asked about KN95 respirators. D’Alessandro said that NIOSH has evaluated numerous KN95 respirators, but approximately half of the respirators evaluated have not met the requirements of the purported standard. FDA has an emergency use authorization for KN95 respirators that identifies those KN95 respirators that do perform to filtration requirements that are similar to the NIOSH requirements.
9 More information about this memorandum of understanding is available from https://www.fda.gov/about-fda/domestic-mous/mou-225-18-006 (accessed September 10, 2020).