If you have doubts about washing a particular item in the dishwasher, check with the manufacturer to see if it is dishwasher-safe.
Materials/items safe to be washed in the dishwasher:
Aluminum is dishwasher-safe; however, high water temperatures and detergents can affect the finish of anodized aluminum.
Always check the manufacturer's recommendations before washing. Antique, hand-painted, or over-the-glaze patterns may fade. Gold-leaf patterns can also discolor or fade.
Check the manufacturer's recommendations before washing. Some types of leaded crystal can etch with repeated washings.
Glass is dishwasher-safe; however, milk glass yellows with repeated dishwasher washing.
Plastics are dishwasher-safe; however, always check the manufacturer's recommendations before washing. Plastics vary in their capacity to withstand high temperatures and detergents. Load plastics in top rack only.
Run a rinse cycle if not washing immediately. Prolonged contact with food containing salt, vinegar, milk products or fruit juice can damage finish.
Sterling Silver or Silver Plate
Run a rinse cycle if not washing immediately. Prolonged contact with food containing salt, acid or sulfide (eggs, mayonnaise and seafood) can damage finish. Also, sterling silver or silver-plated silverware should not be placed in direct contact with stainless steel flatware. The contact point can cause an electrolytic action to take place, causing permanent pitting of the sterling.
Materials/items not safe to be washed in the dishwasher:
Do not wash throwaway aluminum pans in the dishwasher. These might shift during washing and transfer black marks to dishes and other items.
Bottles and Cans
Wash bottles and cans by hand. Labels attached with glue can loosen and clog the spray arms or pump and reduce washing performance.
Seasoning will be removed, and iron will rust.
Gold-colored flatware will discolor.
Handles of some knives are attached to the blade with adhesives that can loosen if washed in the dishwasher.
Pewter, Brass, Bronze
High water temperatures and detergent can discolor or pit the finish.
These items cannot withstand high water temperatures and detergents.
Tin can rust.
Wash by hand. Always check manufacturer's instructions before washing. Untreated wood can warp, crack, or lose its finish.