The questions asked of this committee with regard to respiratory protection measures were narrow (see Box 1-1, Chapter 1), specifically

  • what measures can be taken that would permit the reuse of disposable N95 respirators in healthcare settings?

  • what is known about the need for, and development of, reusable face masks for healthcare providers and the general public?

In the short time available, the committee reviewed the published literature on respirator and mask effectiveness, infectious disease control, and occupational health and industrial hygiene and spoke with representatives of industry, the public health community, government agencies, regulators, and the international community. Despite the extensive literature on respiratory protection, data are severely limited in some critical areas, leading the committee to rely on its collective judgment about what would constitute responsible and safe reuse of N95 filtering facepiece respirators or medical masks.

Existing literature and guidance indicate that there is a hierarchy of respiratory protection, with some respirators offering higher levels of safety than others. The committee was asked to focus on N95 filtering facepiece respirators and medical masks because they are affordable, widely available, and likely to be used in the event of an influenza pandemic. The committee was also asked to assess whether there are any cost-effective alternatives to N95 filtering facepiece respirators and medical masks that could provide adequate levels of protection and could be used against the influenza virus during a pandemic.

In reaching its conclusions, the committee formed some assumptions. First, of the forms of respiratory protection the committee was asked to consider, N95 filtering facepiece respirators that are certified by the National Institute for Occupational Safety and Health (NIOSH) and properly fit-tested are likely to provide the best protection against influenza to the extent that it may be spread via an airborne route. Similarly, a closely fitting high-efficiency medical mask is likely to provide appropriate protection against droplets, whereas a surgical N95 will provide protection against both droplets and aerosols. While recognizing the methodological and data limitations regarding the efficacy of medical masks as a form of respiratory protection against avian influenza, and in the absence of data to the contrary, the committee concluded that masks are likely to provide far less protection against aerosols than an N95 filtering facepiece but may offer

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