Mould and mildew proliferate easily in the warm, moist environment of the shower. However, products safe to use on mouldy wall tile are not always safe to use on shower doors. Many shower doors are made from glass that is supported in an anodised aluminium frame. Aluminium is not difficult to clean, but abrasive cleaners, acidic cleaners and bleach may harm its protective (anodised) finish. Fortunately, mould does not adhere well to aluminum's smooth surface and is easily removed.
Open a window and the bathroom door to allow ventilation. Many cleaners, even mild bathroom cleaners, give off fumes.
Put on rubber gloves and spray a non-abrasive bathroom cleaner on the mouldy areas. Use only a cleaner deemed safe for aluminium shower doors (check the label before using).
Wet a sponge with hot water. Scrub the mould and cleaner off of the aluminium. Pay extra attention to seams and corners where mould likes to hide. If it doesn't come off on the first try, spray it again with cleaner.
Rinse the sponge under the running water and wipe down the entire shower door. Turn off the water and use a soft towel to wipe the shower door dry.
Prevent mould and mildew growth by wiping the aluminium with a towel after each shower (and leaving the bathroom door open for good airflow). If mould is stubbornly clinging, gently scrub it with a soft-bristled toothbrush and plenty of cleaner and water. Do not apply more force than necessary.
According to the Bath Enclosure Manufactures Association, you should not use steel wool or other abrasive cleaning tools, nor should you use vinegar, bleach, or abrasive cleaners on shower enclosures.