At the request of the Centers for Disease Control and Prevention (CDC) and the Occupational Safety and Health Administration (OSHA) the Institute of Medicine convened the Committee on Respiratory Protection for Healthcare Workers in the Workplace Against Novel H1N1 Influenza A to provide recommendations regarding the necessary respiratory protection for health care workers against novel H1N1 influenza A.

The committee focused solely on the scientific and empirical evidence regarding the efficacy of various types of personal respiratory protective equipment (medical masks and respirators). Studies on influenza transmission show that airborne (inhalation) transmission is one of the potential routes of transmission. N95 respirators are documented to filter out 95 to 99 percent of relevant particles and have maximum effectiveness when properly fitted to the face of users. Research results on the filtration and fit of medical masks show wide variation in penetration of aerosol particles and inadequate fit suggesting that the use of medical masks is unlikely to be effective against airborne transmission.

The committee recommends that health care workers (including those in non-hospital settings) who are in close contact with individuals with nH1N1 influenza or influenza-like illnesses should use fit-tested N95 respirators or respirators that are demonstrably more effective as one measure in the continuum of safety and infection control efforts to reduce the risk of infection.

• The committee endorses the current CDC guidelines and recommends that these guidelines should be continued until or unless further evidence can be provided to the effect that other forms of protection or other guidelines are equally or more effective.

• Employers should ensure that the use and fit testing of N95 respirators be conducted in accordance with OSHA regulations, and healthcare workers should use the equipment as required by regulations and employer policies.

The committee also recommends increased research on influenza and personal respiratory protection.