For job sites in which employees may be working with toxic airborne chemicals, a great amount of dust or other particles that could get into the lungs, workers should be required to wear an air purifying respirator. An air purifying respirator is a more advanced and better suited equipment piece than a regular dust mask. While most dust masks are effective at keeping out most dust and particles out of the nose and mouth, they cannot provide clean air to the person wearing the mask. On the other hand, quality respirators have HEPA air filters and an air purifier to not only help keep dust out but ensure the worker is breathing clean air.

A HEPA (High-Efficiency Particulate Arresting) air purifier meets United States Department of Energy (DOE) standards of efficiency. Moreover, these HEPA qualified respirators remove all particles larger than 0.3 micrometers from all air that passes through it (the actual standards require 99.7 percent of those particles to be removed from the air). This creates a clean, dust and particle free working environment for everyone on the site.

In order for a respirator such as this to be effective, it should have several functions that allow the user to manually adjust it. An inhalation valve, for example, allows for a pressure seal check to ensure the mask is on correctly and that only purified air is coming through. The facepiece should not be able to collapse. To ensure this, a pliable combination of plastic and rubber can be used on some masks for both stability and user comfort. Any sealing surface that reduces facial pressure points from the seal area can also add to the user's comfort.

A HEPA air filter-enforced face mask helps cut down on particle exposure on-site.