Who is qualified to wear a respirator?

The correct choice highlights that individuals must be determined to be medically fit before wearing a respirator. This requirement is crucial because wearing a respirator can impose additional physiological demands on the body, which may not be suitable for everyone. Medical evaluations ensure that the individual’s health status allows them to safely use a respirator without risking their well-being or compromising their ability to perform their job effectively.

While training is essential for proper use and understanding of respirators, it does not address the fundamental health considerations that can affect an individual's capacity to wear one effectively. Experience, while beneficial, does not substitute for the necessary health assessments. Similarly, the environment in which an employee works (like outdoor settings) does not automatically qualify them; their specific health status is a critical factor. Therefore, a focus on medical fitness is what makes the correct answer valid and significant in ensuring safety in environments where respirators are required.