8. Certain Plastics
Take-out food or restaurant leftovers often come home in handy plastic containers that beg to be reused. Unless the containers are labeled as dishwasher safe, do not toss them in your dishwasher. The heat and abrasive detergents can break down certain kinds of plastic, leaving them unsafe for storing food. Be sure to check the label, and when in doubt, wash by hand.
7. China and Decorative Dishes
Delicate china teacups and saucers don’t belong in your dishwasher. The harsh conditions and rough and tumble atmosphere are no place for such delicate items. The same goes for any dishes with decorative metal rims. The metal edges can be worn down or eaten away by the caustic chemicals in dishwasher detergents. After an old-fashioned tea party, enjoy a session of old-fashioned dishwashing. Chatting and bonding over a sink of soapy water can be fun, not just drudgery.
6. Cast Iron
Cast iron pots and pans should never go in the dishwasher. The charm of a cast iron pan is keeping it seasoned. To wash cast iron, never use soap or steel wool. Fill your pan with hot water and wash it immediately to prevent rust. Use a stiff brush to give the pan a good cleaning. A paste of salt and water can be used to scour bits of stuck-on food. Towel dry your pan and then rub with a light coating of oil and buff well. If you have already run your pan through the dishwasher or you notice food is sticking to it, you may need to season it again.