JERROLD J. SCHARNINGHAUSEN, Ph.D.
Directorate of Assessments and Prevention
Workplace Safety Division
U.S. Army Combat Readiness Center
Fort Rucker, Alabama
With recent world events, more people are wearing masks and respirators than ever before. While both are designed to provide protection against airborne particulates, there are distinct differences between the two.
The defining characteristic of a mask is that there is not an air-tight seal against the face as there is in the case of respirators. Masks can range anywhere from the disposable models you can purchase by the hundreds for protection from dust to low-end particulate filters and soft, comfortable cloth-based masks. Masks are also referred to as face coverings.
A mask is a loose-fitting device that creates a physical barrier between the mouth and nose of the wearer and potential contaminants. Surgical masks are regulated under Code of Federal Regulation 21 CFR 878.4040. Masks should not to be shared and may come with or without a face shield. Masks are made in different thicknesses and with different ability to protect you from contact with liquids. These properties may also affect how easily you can breathe through the face mask and how well it protects you. If properly worn, a surgical mask is meant to help block large-particle droplets, splashes, sprays or splatter that may contain viruses or bacteria, keeping it from reaching your mouth and nose. Masks may also help reduce exposure of your saliva and respiratory secretions to others. Masks, however, do not provide complete protection from contaminants because of the loose fit between the surface of the mask and your face. It has not been determined if the majority of cloth face masks currently in use provide the same protection as surgical masks since they have not been tested by the same certifying authority.
Disposable masks are not intended to be used more than once. If your mask is damaged or soiled, or if breathing through the mask becomes difficult, you should replace it with a new one. To safely dispose of your mask, place it in a plastic bag and put the bag into the trash. Wash your hands after handling any used mask.
A respirator is a device that uses a filter with a tight seal to the face to remove particles from the air. The most commonly used respirator is a particulate-filtering face-piece respirator. Particulate-filtering face-piece respirators have two different classifications differentiated by a letter and a number. Each respirator can be labeled as N, R or P and 95, 99 or 100. The combination of the letter and the number indicate the specific use for which it was designed.
The letter in front of the description tells what sort of environment the mask can be used. N-series masks are “Not resistant to oil.” They may be used where there are no oil particulates in the atmosphere. R-series masks are “Resistant to oil.” These masks are designed to be used either in an atmosphere where there is no oil particulate, or up to one shift or eight hours of continuous or intermittent use where there is oil particulate present. P-series masks are considered “Oil-Proof.” They may be used in any atmosphere, including those with oil particulates. The manufacturers’ recommended service life of the filter varies, requiring them to be contacted to determine the approved length of use.
The number in the respirator description is basically just a percentage of effectiveness (95, 99 and 100), which can be coupled with each letter designation for a total of nine classifications. A 95-rated mask can filter out 95 percent of particulate matter in the air. This is generally fine for protection from dust and debris. A 99-rated respirator can filter out 99 percent of particulate matter. While this seems adequate and often it is, sometimes that 1 percent that slips through is still dangerous enough that it can be harmful, particularly during long-term exposures. A 100-rated respirator filters 99.97 percent of particulate matter. While a trace amount may still slip through, it is not enough to be harmful without sustained exposure for long periods of time.
An N-95 respirator is required to meet the U.S. National Institute for Occupational Safety and Health (NIOSH) N-95 classification for air filtration. NIOSH is the organization that sets the standards for each classification and performs testing to certify different kinds of respirators and masks as they are produced. The Centers for Disease Control and Prevention (CDC) and the Occupational Safety and Health Administration (OSHA) also regulate N95 respirators.
The N-95 is the most commonly used particulate-filtering face-piece respirator. It uses a type of mechanical filter providing protection against particulates, but not against gases or vapors. The majority of N-95s are manufactured as personal protective equipment for use in construction and other industrial jobs that expose workers to dust and small particulates. An N-95 respirator can make it more difficult for the user to breathe, resulting in shortness of breath and — in extreme cases — unconsciousness. N-95 respirators are not designed for use by children or people with facial hair. The N-95 is designed for adults and does not allow a proper seal on the smaller face structure of children. Individuals with facial hair will be unable to achieve a proper seal with the skin of the face, rendering the respirator useless.
The CDC has gone on record as not recommending that the general public wear N-95 respirators to protect themselves from respiratory diseases, including coronavirus (COVID-19). Standard N-95 industrial respirators have not been tested for effectiveness in protecting against airborne viruses. Only surgical N-95 respirators have been tested for preventing exposure to airborne pathogens.
Based upon the discussion above, it would appear that an N-95 respirator would be a better choice for protection. However, being a respirator, the provisions of Army Regulation 11-34, The Army Respiratory Protection Program, dated 25 July 2013, must be applied. For Army purposes, the use of a respirator requires a written respirator protection program; a medical evaluation and clearance; a respiratory protection program officer appointed on orders; fit testing; and training on the use, storage and maintenance of the respirator. This standard also applies to voluntary use of a respirator, making the use of an N-95 respirator a violation of Army regulation without a full-blown respirator protection program.
Between the cost of using disposable masks and the regulatory requirements of using an N-95 mask, a reusable cloth mask is usually the best choice. The CDC recommends that the public use simple cloth face coverings in a public setting to slow the spread of the virus, since this will help prevent transmitting it to others. The masks are available from a number of sources, and directions for building your own are available on the internet. It is worthwhile to repeat that the CDC recommends wearing face coverings to help you not transmit disease to others, not for the protective factor offered to the user. Whichever option you choose, it will only be effective if it is actually worn correctly.