Face shields are personal protective equipment devices that are used by many workers (e.g., medical, dental, veterinary) for protection of the facial area and associated mucous membranes (eyes, nose, mouth) from splashes, sprays, and spatter of body fluids. Face shields are generally not used alone, but in conjunction with other protective equipment and are therefore classified as adjunctive personal protective equipment. Although there are millions of potential users of face shields, guidelines for their use vary between governmental agencies and professional societies and little research is available regarding their efficacy.
Healthcare workers’ faces have been reported to be the body part most commonly contaminated by splashes, sprays and spatter of body fluids. A face shield is classified as personal protective equipment (PPE) that provides barrier protection to the facial area and related mucous membranes (eyes, nose, lips). A face shield offers a number of potential advantages, as well as some disadvantages, compared with other forms of face/eye protection used in healthcare and related fields (Table 1). The millions of potential users of face shields include healthcare workers, dental providers, veterinary care personnel, laboratory workers, pre-hospital emergency medical providers, police, firefighters, and custodial staff dealing with spills and contaminated waste. It is not precisely known when eye protection first came to be used in the medical field, but records indicate that a 1903 patent was granted to Ellen Dempsey of Albany, New York, for a transparent “sanitary face shield for protection from inhaling disease-producing germs.” In 1974, James H. Bolker was granted a patent for a surgical hood with a clear, plastic faceplate that included a suction system to remove the exhaled breath from under the face plate and, in 1989, a cap with an incorporated face shield designed for non-surgical medical personnel was patented. The introduction of the Occupational Safety and Health Administration’s (OSHA) Bloodborne Pathogens Standard 1910.1–030, as well as recent outbreaks of serious airborne infectious diseases (e.g., Severe Acute Respiratory Syndrome [SARS], Avian Influenza, etc.) and severe infectious agents associated with the potential for body fluid exposures (e.g., Ebola virus), have resulted in increased attention to face/eye protection. The purpose of this article is to provide the reader with a review of the use of face shields for infection control purposes in order to assist in the selection and proper utilization of this type of PPE.
Face shield design and structure
The majority of eye and face protection currently used in the U.S. is designed, tested, and manufactured in accordance with the American National Standards Institute (ANSI)/International Safety Equipment Association (ISEA) Z.87.1–2010 standard. The major structural components of a face shield include the following:
Visor. Visors, also referred to as lenses or windows, are manufactured from any of several types of materials that include polycarbonate, propionate, acetate, polyvinyl chloride, and polyethylene terephthalate glycol (PETG) and come in disposable, reusable, and replaceable models (Figures 1–3). Acetate provides the best clarity and PETG tends to be the most economical, but polycarbonate is one of the most widely used. Polycarbonate and propionate offer better, although still somewhat imperfect, an optical quality that aids in reducing eye strain associated with face shield wear.[9, 11] Visors can be treated with advanced coatings to impart anti-glare, anti-static, and anti-fogging properties, ultraviolet light (UV) protection, and scratch resistance features to extend the life of the visor. Some models come with built-in goggles that are incorporated into the visor.[9, 10] Visors are available in different lengths that include half facepiece length extending to the mid-face, full facepiece length that extends to the bottom of the chin, and a face/neck length that also covers the anterior neck area (Figures 1 and and2).2). Most visors curve around the face and come in different widths; wider visors offer more peripheral protection. Some one-piece face shields have visors that conform to the wearer’s face upon donning (Figure 3). Recommendations from the Centers for Disease Control and Prevention (CDC) are for visors that are of sufficient width to reach at least the point of the ear, as this will lessen the chances of the likelihood that a splash could go around the edge of the face shield and reach the eyes. In addition, visors should have crown and chin protection for improved infection control purposes.[7, 13] Some models of disposable medical/surgical face masks are available with an integral, thin plastic visor fitted to the top of the mask with an anti-fogging device between them to reduce the effects of exhaled moisture (Figure 4).[12