When is a fit test for respiratory protection typically required?

A fit test for respiratory protection is typically required before initial use and periodically thereafter to ensure that the respirator forms a proper seal around the user's face. This is vital because an effective protective barrier is necessary for the respirator to perform its intended function of filtering or providing clean air.

The initial fit test confirms that the specific respirator model chosen is suitable for the wearer’s facial structure. Periodic retesting is necessary to account for any changes in a person's physical condition, such as weight fluctuations, facial hair growth, or the wearing of glasses, all of which could affect the respirator’s fit.

This approach aligns with safety regulations and best practices, ensuring that the protective equipment remains effective over time. The other options do not encompass the comprehensive nature of the fit testing requirements, as fit testing should not be limited to the initial use or tied solely to annual safety trainings.