The right mask can help prevent swine flu

People covered with facemasks are a common sight in news reports from Mexico about the swine flu outbreak. Do people in the U.S. now need to consider wearing masks, and can they really help?

The Mexican government has been handing out face masks to its citizens. In areas where the flu has already reached epidemic proportions, it may be advisable to wear masks in all public places.

In the U.S., where most infections are now clustered in communities, it makes sense to wear a high-grade mask in situations where you're likely to be exposed to the virus. For example, if you're sick with the flu, wearing a mask can help prevent spreading it to others. And if you're caring for someone who is sick, wearing a mask yourself can also help reduce exposure to the droplets from a cough or sneeze that spread infection. If there is an outbreak in your community, masks can be helpful tools to reduce your exposure to the virus in confined or crowded places, like buses, trains, and airplanes.

Not all masks are created equal. To prevent the inhalation of most virus-bearing droplets from a cough or sneeze masks and respirators should be labeled N-95* or higher, which means they have been cleared by the FDA. They may also bear a label from the National Institute for Occupational Safety.

How a mask fits is a big influence on its effectiveness. The mask should fit tightly over your nose and mouth, with no gaps. To get the full protective effect, you'll need to wear it as long as you're in a high risk situation and replace it after each use.

Masks can help, but are no replacement for basic preventative hygiene, which can go a long way in protecting you from the flu. Wash your hands vigorously for 20 seconds under warm running water before eating or preparing meals, after the using the bathroom, after blowing your nose, and after other potential exposures to the flu virus. Alcohol based hand sanitizer, like Purell, with an alcohol content of at least 60 percent, can be effective, when soap and hot water aren't an option.

—Urvashi Rangan, Technical Policy Director, Consumers Union

Read more on whether or not masks can protect you (scroll down to #13).