Surgical mask

Surgeon wearing surgical mask at California Pacific Medical Center.

A surgical mask, also known as a procedure mask, is intended to be worn by health professionals during surgery and during nursing^[1] to catch the bacteria shed in liquid droplets and aerosols from the wearer's mouth and nose. Its first recorded use was by the French surgeon Paul Berger during an 1897 operation in Paris.

Surgical masks are also popularly worn by the general public in East Asian countries to reduce the chance of spreading airborne diseases; in Japan, it is common to wear a face mask whilst ill to avoid infecting others in public settings.^[2] Surgical masks were widely used in China, Hong Kong, Vietnam, and Toronto, Canada during outbreaks of the SARS virus, during the 2007 bird flu pandemic in Japan, and in the United States and Mexico City during the 2009 flu pandemic featuring swine flu and the H1N1 virus. They are also worn by people in dusty environments such as sanitation workers.

In higher risk environments, N95 or NIOSH masks may be used in place of surgical masks as they provide better protection due to their shape and securing straps.

Modern surgical masks are made from paper or other non-woven material and should be discarded after each use.^[3]

Usage

Without the manifold buffers afforded by a surgical mask, airborne diseases can be easily transferred via respiratory droplets

Simple surgical masks protect wearers from being splashed in the mouth with body fluids, and prevent transmission of body fluids from the wearer to others, e.g. the patient. They also remind wearers not to touch their mouth or nose, which could otherwise transfer viruses and bacteria after having touched a contaminated surface (fomite). They can also reduce the spread of infectious liquid droplets (carrying bacteria or viruses) that are created when the wearer coughs or sneezes. There is no clear evidence that disposable face masks worn by members of the surgical team would reduce the risk of wound infections after clean surgical procedures.^[4] Surgical masks are not designed to protect the wearer from inhaling airborne bacteria or virus particles. They may trap some particles but are less effective than respirators, which are designed for this purpose.

Evidence supports their effectiveness in reducing the risk of infection among other healthcare workers and in the community.^[5]

Safety guidelines for healthcare workers recommend the wearing of a face-fit tested respirator mask conforming to United States standard NIOSH N95 or European standard EN 149 FFP3 in the vicinity of pandemic-flu patients, to reduce the exposure of the wearer to potentially infectious aerosols and airborne liquid droplets.^[6][7]

A Kimberly-Clark procedure mask.^[8] Note the full facial shielding and the Droplet Isolation protocol signage.

During the 1918 flu pandemic, a street car conductor in Seattle, USA refuses a person who attempts to board without wearing a mask.

The U.S Centers for Disease Control and Prevention (CDC) provides additional information on manufacturers' products, as well as the importance of correct fitting of such masks (respirators). A printable factsheet has been designed for issue to those unaccustomed to respirator use.^[9]

In community settings, according to the CDC in its guidance regarding the 2009 swine flu outbreak, the use of facemasks must be coupled with other measures such as avoiding close contact and maintaining good hand hygiene to reduce the risk of getting influenza.^[3]

Cotton and gauze masks are also available but do not serve as surgical masks as they do not offer adequate filtration of microbes. Some people wear these over a normal surgical mask as they often feature patterns and designs that are more attractive and fashionable.

• Cryptomeria japonica discharges a large amount of pollen in spring. To prevent allergic rhinitis with the pollen of Cryptomeria japonica, the mask is used in Japan.
• In Japan and Taiwan, it is common to see these masks worn while ill, as a show of consideration for others and social responsibility.^[10]

Design

Typical 3-ply surgical masks. The top one has the right side up and the bottom one up side down. The edge with double stitches is designed to cover the nose, and a metal wire is concealed within so the mask could be fitted to the contour of the nasal bridge.

The design of the surgical masks depends on the mode; usually the masks are 3 ply/3 layers. This 3 ply material is made up from a melt-blown material placed between non-woven fabric. The melt-blown material acts as the filter that stops microbes from entering or exiting the mask. Most surgical masks feature pleats or folds. Commonly, 3 pleats are used allowing the user to expand the mask so it covers the area from the nose to the chin. Currently there are 3 different ways to secure the masks. The most popular is the ear loop; this is where a string like material is attached to the mask and placed behind the ears. The other methods are the tie-on and the head band. The tie-on straps consist of four non-woven straps that are tied behind the head. The head band is an elastic strap that is placed behind the head.

Surgical masks with decorative designs are popular in countries where they are worn in public.

Developments

Several new masks are about to market new mask features. One feature is a no-strap design that uses adhesive to secure the mask to the face, leaving no gaps.

Non health-related uses

The mythological figure Kuchisake Onna is commonly seen with a surgical mask to hide the scars on her mouth. Pop star Michael Jackson often wore a surgical mask when in public to conceal his identity.

See also

• Dust mask
• Respirator

References

Wikimedia Commons has media related to Surgical masks.