Masks, facial cloth coverings, PPE (personal protective equipment), and respirator are all used interchangeably yet have distinct meanings. Let’s explore the different types of masks you might be considering for back-to-school.
A facial cloth covering
These are pieces of cloth that cover the nose and mouth of the wearer with loops over the ear. They help keep the wearer from spreading respiratory secretions when talking, sneezing, or coughing, and therefore provide some protection for the people around them. Depending on the material and number of layers, they may provide some protection for the wearer but that is not their prime function. Generally, we recommend coverings made of at least two layers. Facial cloth coverings should be changed if wet or soiled and washed each day.
Procedure (or surgical) mask
A procedure mask is a loose-fitting, disposable device cleared by the U.S. Food and Drug Administration that creates a physical barrier between the mouth and nose of the wearer and the environment. A surgical mask helps block large-particle droplets, splashes, sprays, or splatter that may contain bacteria or viruses from reaching the wearer’s mouth and nose. Surgical masks also help keep the wearer from spreading respiratory secretions when talking, sneezing, or coughing. Surgical masks are for single-day use and should be replaced if wet or soiled. Currently, the National Academy of Sciences recommends all teachers wear procedure masks in the school environment.
Window (clear) mask
This is a modification of a procedure mask so that the lips of the wearer can be seen. These masks are used in special circumstances when it is critical for the student to be able to see the wearer’s lips.
A respirator is a personal protective device that covers at least the nose and mouth and is designed to protect the wearer from not only large droplet particles but also small droplets and aerosols.
The National Institute for Occupational Safety and Health (NIOSH) evaluates, tests, and approves respirators. Respirators include the marking on the device itself and are intended for maximum wearer protection. They will also very effectively keep the wearer from spreading respiratory secretions when talking, sneezing, or coughing.
Respirators tend to be quite a bit thicker, less flexible, and harder to breathe through than surgical masks. Fit-tested respirators (i.e., respirators that are tested for tight fit) provide the greatest protection. Others come in a single size and may not be fit tested. These offer excellent protection but not to the same degree as those that are fitted to the face.
We describe respirators with a letter and a number. The first part of the rating can either be an N, R, P, or K. The letters N, R, and P are US standards and describe how tight the weave and how resistant the device is to oil. In medical and school environment we use “N” masks, which protect against solid and liquid airborne particles but not oil. The letter “K” refers to a Chinese standard rather than a US standard for respirators, and it does not necessarily exactly match US standards. The numeric half of the rating refers to the percentage of 0.3 micron particles the filter will remove from the air. An “95” mask means the mask will filter out at least 95% of the particles.
A valved N95 mask allows for direct exhalation of air by the wearer. They should NOT be allowed in the school setting as they are specifically designed to protect the wearer and provide NO protection against transmission to others.