Why are my plastics turning black?
There are two potential causes that exist for black/grey discoloration:
- Mildew - Mildew is fairly unlikely to occur in a dishwasher due to the chemistry and heat associated with the cleaning action. It is possible however mildew could develop between cycles. Avoid leaving wet dishes in the dishwasher for long periods of time with the door closed.
- Silver oxide - Another possible source of black/grey discoloration is the formation of silver oxide caused by washing items made from actual silver. The dishwasher chemistry attacks the silver and forms a silver oxide which then deposits on the plastic components. Modern silverware is more commonly made from stainless steel and does not cause this problem.
How to remove it?
If discoloration becomes excessive, use a household cleaner and a microfiber cloth, this will usually remove the discoloration.