Dust on a bathroom exhaust fan grille reduces airflow and allows moisture to linger. Cleaning the cover and the accessible housing improves ventilation without putting water near the motor.
Turn off power
Switch the fan off and turn off its circuit at the panel if the cover must be removed. Confirm the fan cannot start, then gently pull the grille down and release its spring clips.
Clean the cover
Vacuum loose dust outdoors or over a bin, then wash the grille in warm soapy water if its material allows. Dry it completely. Use a soft brush and vacuum around the housing, keeping liquid away from electrical parts.
Inspect airflow
Check that the damper and visible duct opening are not blocked. Do not reach deep into the duct or bend the fan blades. If the motor is noisy, the grille is damaged, or moisture remains after use, arrange service.
Clean the grille every few months and run the fan during showers and afterward as recommended by the manufacturer.