Black mould can grow in washing machines. It mostly grows on the door seal and in the soap dispenser and the box the soap drawer fits into. On the soap dispenser it can divert jets of water to the front and cause water to leak from the soap drawer. Remove the soap dispenser drawer and check the top of the dispenser compartment where the water comes in and use a suitable long handled brush or an old toothbrush to remove it. Never use a wire brush as this will damage the plastic. Black mould is known to release spores and there are known health hazards with black mould such as allergies and some illnesses although as it's so damp in a washing machine it's possible the spores don't get released so easily unless scrubbing them. You may be able to scrub lightly affected areas of the door seal with a brush or old toothbrush etc. and “Ciff” or a similar kitchen surface cleaner, or if the mould is bad a use bathroom mould remover spray. A environmentally safe method is to use white wine vinegar. To be on the safe side you should wear gloves goggles when dealing with black mould. We do not recommend the use of strong bleach as this can damage the washing machine and is not good at preventing the mould from reoccurring. Please read the instructions to make sure it is safe to use on rubber if intending to use it on the door seal. After cleaning the soap drawer and soap drawer box we strongly recommend performing a maintenance or service wash to remove all the loosened mould and clear the washing machine of chemicals. See What is a maintenance or service wash ? section of this document. If badly affected - the only way to get rid of it - is to replace the door seal or soap drawer box and this is an expensive option.