What items are not safe to wash in my dishwasher?

Do not wash iron (will rust), pewter (will tarnish), tin (will rust), or wood (can warp, crack or lose finish). Do not wash non-dishwasher safe plastics, antique or metal-trimmed china, or items such as electronic air cleaner filters, furnace filters, or paint brushes. Sterling silver should not be washed with stainless steel utensils in the same load.