OccuSafe Industrial Hygiene Consulting

N-95 air purifying facemasks are now widely used to prevent the spread of COVID-19 during the pandemic. They provide better protection than surgical and homemade masks since they have been tested by the National Institute of Occupational Safety & Health to be 95% efficient in providing protection against particulates, aerosols, and mists. With some exceptions, N-95 facemasks do not have inhalation and exhalation valves (small rubber flappers that open or close during respiration). Air is solely filtered through the facepiece when breathing in and out. Where there is a concern about the user infecting persons in his/her immediate area while the user is still protected, an N-95 facemask is the best choice.

Some N-95 facemasks are equipped with one-way exhalation valves that make it easier to exhale since air passes through the valve instead of the facemask upon exhalation. They do not protect persons in the area from contamination from the user and should not be used in settings where that is a concern.

There are many types of air purifying respirators manufactured with exhalation and/or inhalation valves. Air purifying respirators are made in a number of configurations and can be equipped with canisters and filters that protect the user from a wide variety of contaminants. They are also manufactured in different sizes and can be tested to get the best fit for respirator wearer. When breathing in, the inhalation valves open while the exhalation valve remains closed. The reverse is true with exhalation. Valves themselves do not filter air, but in combination with respirator filters keep the user from breathing contaminated air in his/her surroundings and makes it easy to exhale with very little resistance. Air purifying respirators, can do an excellent job of protecting the user from airborne contaminants, but they do not protect nearby persons from exposure from the respirator user. This is especially significant during the COVID-19 crisis.

During this COVID-19 pandemic, it is very important to choose the right respirator for the job. If the aim is to best protect the user, then an air-purifying respirator with inhalation and exhalation valves may be best. But if it is more important to protect both the respirator user and people in the area, then an N-95 facemask without an exhalation valve may be best.

Be well, be smart, be 6 feet apart

OccuSafe Industrial Hygiene & Safety, Inc. provides skills and expertise to recognize, evaluate and control hazards and injuries in the areas of industrial hygiene, occupational safety and health. OccuSafe services companies of all sizes in a range of industries.

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