CDC - Influenza (Flu) | Swine Flu: Interim Recommendations for Fac...here Swine Influenza A (H1N1) Virus Transmission Has Been Detected

Swine Flu

Interim Recommendations for Facemask and 

Respirator Use in Certain Community Settings Where 

Swine Influenza A (H1N1) Virus Transmission Has Been 

Detected

April 27, 2009 011:00AM ET

This document provides 

interim guidance and will be 

updated as needed.

Detailed background 

information and 

recommendations regarding 

the use of masks and 

respirators in nonoccupational community 

settings can be found on 

PandemicFlu.gov in the 

document Interim Public 

Health Guidance for the Use 

of Facemasks and Respirators 

in Non-Occupational 

Community Settings during an 

Influenza Pandemic .

Information on the effectiveness of facemasks1

 and respirators2 for the control of influenza in community 

settings is extremely limited. Thus, it is difficult to assess their potential effectiveness in controlling swine 

influenza A (H1N1) virus transmission in these settings. In the absence of clear scientific data, the interim 

recommendations below have been developed on the basis of public health judgment and the historical use of 

http://www.cdc.gov/swineflu/masks.htm (1 of 3) [4/27/2009 1:45:09 PM]
CDC - Influenza (Flu) | Swine Flu: Interim Recommendations for Fac...here Swine Influenza A (H1N1) Virus Transmission Has Been Detected

facemasks and respirators in other settings.

In areas with confirmed human cases of swine influenza A (H1N1) virus infection, the risk for infection can be 

reduced through a combination of actions. No single action will provide complete protection, but an approach 

combining the following steps can help decrease the likelihood of transmission. These actions include 

frequent handwashing, covering coughs, and having ill persons stay home, except to seek medical care, and 

minimize contact with others in the household. Additional measures that can limit transmission of a new 

influenza strain include voluntary home quarantine of members of households with confirmed or probable 

swine influenza cases, reduction of unnecessary social contacts, and avoidance whenever possible of crowded 

settings.

When it is absolutely necessary to enter a crowded setting or to have close contact3 with persons who might 

be ill, the time spent in that setting should be as short as possible. If used correctly, facemasks and 

respirators may help reduce the risk of getting influenza, but they should be used along with other preventive 

measures, such as avoiding close contact and maintaining good hand hygiene. A respirator that fits snugly on 

your face can filter out small particles that can be inhaled around the edges of a facemask, but compared with 

a facemask it is harder to breathe through a respirator for long periods of time. More information on 

facemasks and respirators can be found at www.cdc.gov/swineflu.

When crowded settings or close contact with others cannot be avoided, the use of facemasks1 or respirators2

in areas where transmission of swine influenza A (H1N1) virus has been confirmed should be considered as 

follows:

1. Whenever possible, rather than relying on the use of facemasks or respirators, close contact with 

people who might be ill and being in crowded settings should be avoided. 

2. Facemasks1

 should be considered for use by individuals who enter crowded settings, both to protect 

their nose and mouth from other people's coughs and to reduce the wearers' likelihood of coughing on 

others; the time spent in crowded settings should be as short as possible. 

3. Respirators2 should be considered for use by individuals for whom close contact with an infectious 

person is unavoidable. This can include selected individuals who must care for a sick person (e.g., 

family member with a respiratory infection) at home. 

These interim recommendations will be revised as new information about the use of facemasks and 

respirators in the current setting becomes available. 

For more information about human infection with swine influenza virus, visit the CDC Swine Flu website.

1 Unless otherwise specified, the term "facemasks" refers to disposable masks cleared by the U.S. Food and 

Drug Administration (FDA) for use as medical devices. This includes facemasks labeled as surgical, dental, 

medical procedure, isolation, or laser masks. Such facemasks have several designs. One type is affixed to the 

head with two ties, conforms to the face with the aid of a flexible adjustment for the nose bridge, and may be 

flat/pleated or duck-billed in shape. Another type of facemask is pre-molded, adheres to the head with a 

http://www.cdc.gov/swineflu/masks.htm (2 of 3) [4/27/2009 1:45:09 PM]
CDC - Influenza (Flu) | Swine Flu: Interim Recommendations for Fac...here Swine Influenza A (H1N1) Virus Transmission Has Been Detected

single elastic band, and has a flexible adjustment for the nose bridge. A third type is flat/pleated and affixes to 

the head with ear loops. Facemasks cleared by the FDA for use as medical devices have been determined to 

have specific levels of protection from penetration of blood and body fluids. 

2 Unless otherwise specified, "respirator" refers to an N95 or higher filtering facepiece respirator certified by 

the U.S. National Institute for Occupational Safety and Health (NIOSH). 

3 Three feet has often been used by infection control professionals to define close contact and is based on 

studies of respiratory infections; however, for practical purposes, this distance may range up to 6 feet. The 

World Health Organization uses "approximately 1 meter"; the U.S. Occupational Safety and Health 

Administration uses "within 6 feet." For consistency with these estimates, this document defines close contact 

as a distance of up to 6 feet.

● Links to non-federal organizations are provided solely as a service to our users. These links do not 

constitute an endorsement of these organizations or their programs by CDC or the federal 

government, and none should be inferred. CDC is not responsible for the content of the individual 

organization Web pages found at these links. 

File Formas Help:

● 

● 

● 

● 

● 

● 

● 

● 

How do you view different file formats(PDF, DOC, PPT, MPEG) on this site?

● Page last reviewed April 27, 2009 11:00 ET 

● Page last updated April 27, 2009 11:00 ET 

● Content source: Centers for Disease Control and Prevention 

Centers for Disease Control and Prevention 1600 Clifton Rd. Atlanta, GA 30333, USA 

800-CDC-INFO (800-232-4636) TTY: (888) 232-6348, 24 Hours/Every Day - cdcinfo@cdc.gov

http://www.cdc.gov/swineflu/masks.htm (3 of 3) [4/27/2009 1:45:09 PM]