Key Questions
The following key questions are answered in this module:
What does the "N95" rating on a dust mask mean?
Rating letters indicate whether masks are oil proof (P), oil resistant (R), or not oil resistant (N), and rating numbers indicate the percentage of particles at least 0.3 microns in diameter that the mask will remove. An "N95" dust mask is not oil resistant and it will filter out 95% of particles at least 0.3 microns in diameter.
Why would someone choose an N95 dust mask over an N100 dust mask? Isn't it better to filter out more particles?
N100 dust masks do remove more particles but they also tend to be hotter and harder to breathe through, so someone might choose an N95 dust mask for comfort reasons.
What are the requirements regarding the type of dust mask purchased by an employer?
OSHA requires that dust masks used for voluntary protection be certified by NIOSH, the National Institute for Occupational Safety and Health, for use to protect against the contaminants present.
Are OSHA's requirements for dust masks and other more complex respirators very different?
OSHA's requirements for the voluntary use of more complex respirators, such as tight-fitting elastomeric respirators, are more involved because they are physiologically more burdensome than dust masks. However, the requirements are still less involved than those for a full Respiratory Protection Program.
Why are OSHA's requirements so stringent?
OSHA's requirements are stringent in order to protect against hazards including undetected medical conditions which could jeopardize an employee's health, dirty respirators which could lead to skin problems, and dirty respirators which could expose the worker to build up and contaminants.