Under what condition is an employee prohibited from wearing a tight-fitting respirator?

The correct condition under which an employee is prohibited from wearing a tight-fitting respirator is when facial hair interferes with the seal. Tight-fitting respirators rely on a good face seal to provide adequate protection from airborne contaminants. If there is facial hair, such as a beard or mustache, it can prevent the respirator from forming a proper seal against the skin. This can lead to air leakage around the edges of the mask, compromising the effectiveness of the respirator and potentially exposing the wearer to harmful substances.

The importance of a good seal cannot be overstated, as even a small gap can significantly reduce the respiratory protection offered by the device. Therefore, individuals with facial hair that affects the fit of a tight-fitting respirator must either remove the facial hair or use a different type of respiratory protection that does not require a tight seal, such as a loose-fitting hood or helmet.

Understanding the proper conditions for wearing respirators is crucial for maintaining health and safety in environments where respiratory hazards exist. This ensures that workers are adequately protected while performing their tasks.