Respiratory protection and the flu
Answered by Laurel A. Alvarez, senior technical service specialist, 3M Occupational Health and Environmental Safety Division, St. Paul, MN.
It is probable that H1N1 influenza is spread from person to person in several ways. A particulate respirator is only one of several preventive measures that can be used to help reduce exposure to the virus that causes H1N1 influenza. The Centers for Disease Control and Prevention recommends that infection control practices in the workplace include proper handwashing, respiratory hygiene and cough etiquette. CDC also suggests employers encourage sick workers to stay home and away from the workplace to help avoid the spread of infectious diseases.
Particulate respirators are designed to help reduce exposures of the wearer to airborne particles. Airborne germs, such as bacteria or viruses, are particles and can be filtered by particulate filters with the same efficiency as nonbiological particles having the same physical characteristics (size, shape, etc.). A particulate respirator's ability to help reduce wearer exposure to airborne germs depends on the filtration capabilities of the materials it is made of and on how well it fits the wearer. If a respirator is selected, it is important that it be NIOSH-approved for particles. It also is important for the wearer to be fit-tested and trained to follow all directions on how to use and put on a respirator. Putting the respirator on correctly means more of the air the person breathes goes through the respirator filter. Occupational use of respirators must be in the context of a respiratory protection program in accordance with OSHA's respiratory protection standard (29 CFR 1910.134).
Although respirators can help reduce exposure to the virus that causes H1N1 influenza, they are not a guarantee the user will not contract H1N1 influenza, as many additional factors exist:
- Respirators may help reduce exposure to the number of airborne germs, but they do not eliminate all of them, nor do they prevent entry of germs through the skin, eyes or other parts of the body. Other protective equipment may be needed. Frequent handwashing and other infection-control measures recommended by CDC are very important.
- Particulate respirators help reduce, not eliminate, exposure to airborne particles. Even if a filter is 100 percent efficient, the expected amount of exposure reduction would be limited by the respirator's assigned protection factor. APF is the expected ability of the respirator to reduce exposure when used according to an effective respiratory protection program. Because respirators will not prevent the inhalation of all particles, they cannot eliminate the risk of exposure, infection and illness.
- For greatest effectiveness, respirators need to be worn during all potential exposures.