How often should N95 mask be re-evaluated and fit tested?

N95 masks should be re-evaluated and fit tested regularly, typically at least annually, or whenever there is a change in the user's physical condition, such as significant weight loss or gain, dental work, or facial surgery. Additionally, fit testing should be conducted whenever a new model or brand of N95 is used. It's essential to ensure that the mask continues to provide an adequate seal and effective protection. Regular checks help maintain safety standards in environments where respiratory protection is crucial.