Because washing machines are exposed to large amounts of water, it is not uncommon for them to develop mould and mildew around the rubber gaskets that line the doors. This issue seems to particularly affect front-loading washers. If the door or lid to the washer is not left open after use, the water cannot evaporate and creates a breeding ground for mould. You can remove the mould from the gasket and restore the appearance and smell of the machine.
Put on rubber gloves and safety glasses before commencing the cleaning process.
Lay an old towel or dust sheet on the floor under the front of the washer to prevent floor damage as you clean.
Fill a plastic cup with bleach and dip a tooth brush into the bleach.
Remove the toothbrush and scrub the washing machine gasket with it to remove the black mould from it. Hold the gasket open with the fingers of your other hand so that you can clean the centre grooves of the gasket where the most mould is likely to grow.
Rinse the toothbrush in the cup of bleach and continue cleaning until you have removed the mould from the entire gasket.
Wipe the gasket with a paper towel to remove excess bleach residue and any remaining mould.
To prevent new mould from forming on the washing machine gasket, wipe it dry after every use. In addition, leave the washer door or lid open for one to two hours after use to allow the moisture to evaporate. If your washing machine has a "Clean" cycle, you should run it immediately after removing the mould using the instructions for your washing machine.