The Air We Breathe by Terrence Jaimungal

Elimination of personal exposure through engineering controls (e.g., fume hoods, biological safety cabinets) and safe work practices is the best protection from airborne hazards. The use of respirators, like other items of personal protective equipment (PPE) is considered a "last line of defense" and should be relied upon only when engineering and other control methods are not effective or feasible.

A respirator is a device designed to protect the wearer from inhaling harmful dusts, fumes, vapors, microorganisms, or other airborne materials. There is a wide range of respirator types and sizes used for various purposes, but two main categories are: the air-purifying respirator, including the N-95 mask, which forces contaminated air through a filtering element, and the air-supplied respirator, in which an alternate supply of fresh air is delivered to the wearer.

Wearing a respirator in the workplace is not as simple as buying one and putting it on. In fact, there is a very specific protocol dictated by the Occupational Safety and Health Administration (OSHA) that must be followed in order to wear a respirator at work. The purpose of the protocol is to ensure the use of the respirator is necessary, appropriate for the anticipated hazards and that the additional burden on the respiratory system caused by respirator use is appropriate considering the user's health status.

To determine respirator necessity, EH&S must conduct a hazard evaluation/exposure assessment of the work activity. If the assessment indicates that that the level of airborne contaminants exceed permissible levels and cannot be reduced by a change in the activity or via engineering controls, EH&S will recommend respirator use. EH&S will then assist in selecting the respirator that is appropriate for the airborne hazard(s). This step is critical as not all respirators are designed to filter out all contaminants. Selection of the wrong respirator or filter is one of the most common errors made by people who voluntarily choose to wear a respirator. Selection must be made by a trained professional who understands the concentration of the airborne contaminant(s), the type of respirator filter that will effectively filter the contaminant(s) and the concentration of contaminant(s) that the respirator is capable of filtering. Next, before a respirator can be worn, the user must be evaluated by a medical professional and receive medical clearance to wear a respirator. Once medical clearance is granted, EH&S will need to perform a fit-test of the respirator to ensure the respirator fits properly and will not allow contaminants to leak in through gaps between the face and respirator seal. This process will require the user to be clean shaven so there is no hair between the respirator's seal and user's face. Lastly, EH&S will train the user on proper use and care of the respirator. Once the process is complete, the user will be enrolled in the University's Respiratory Protection Program, which will allow EH&S to track the user and annually validate the continued need for the respirator, repeating the above process.

If you are wearing a "mask" at work, the first thing to do is determine if the "mask" is a respirator or a simple dust mask or surgical mask (note: N95 respirators look very similar to common dust masks, but because they are technically air purifying respirators, the user is subject to the Respiratory Protection Program). If you determine that what you are wearing is a respirator, contact EH&S immediately and we will help determine the best approach to keep you protected from airborne contaminants. DO NOT put yourself at risk by taking it upon yourself to select and use a respirator. To learn more about respirators and their differences, please visit

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