5 Kitchenware Items You Should Never Clean in the Dishwasher

Dishwashers are wonderful appliances. Along with saving you from the task of washing your dishes by hand, these machines are designed to give your dirty plates and utensils a deep and thorough clean—without using as much water as you would in the sink.

Unfortunately, not all kitchenware is a good candidate for the dishwasher. While many items are composed of dishwasher-safe materials, others become damaged when exposed to heat and water pressure. "Both dishwashers and dishes have evolved a lot over the years," says Cynthia Fanning, the vice president of product management, dishwashers for GE Appliances. "There are more items that are dishwasher-safe than there used to be," she says. But not everything is a good fit. From fine china to wooden spoons and more, here are the off-limits items you should keep out of the dishwasher—and why.

Fine China

Despite advancements in dishwasher-safe materials, Fanning says that one type of product that should never go into a dishwasher is fine china. "Detergent chemistry can cause the paint on the dinnerware to chip or wear off," she explains. "Additionally, the sizes of fine china tend to be different from standard plates, which can create extra movement and rattling that can cause damage."

Some Plastic

While many plastic items, including BPA-free and polypropylene ones, are safe to use in the dishwasher, others can quickly warp or melt when exposed to hot water and the heat from the drying cycle. For this reason, you should only put plastic wares, such as food containers, that are marked dishwasher-safe in your dishwasher and always on the top rack—which is farther from the heating elements located in the bottom of most models.

Wooden Items

No matter how dirty your beloved wooden spoons, bowls, and cutting boards may be, don't put them in this appliance. Hot water can cause wood to warp, splinter, crack, and lose its finish—and even a small crack or splinter in a wooden utensil, bowl, or board can trap disease-causing germs and bacteria that you don't want anywhere near your food. Stick to hand-washing your wood or wooden-handled items to ensure they're safe to use for longer.

Non-Enameled Cast Iron

As a rule of thumb, pots, pans, and skillets composed of non-enameled cast iron are best kept out of the dishwasher. Not only can the detergents and water pressure cause your cast iron items to rust, your machine can also strip away the valuable seasoning oils that have accumulated on your cookware over time. Unless your cast ironware is enameled, it should be cleaned with water and a damp cloth only—no soap.

Fragile Glassware

As risky as it may seem, a lot of us still try to wash fragile glassware in the dishwasher. Even when placed on the top rack, delicate glasses can chip, crack, and split. Even worse, fragile glassware, such as long-stemmed wine glasses, can get knocked loose during the wash cycle; they can hit each other and shatter, leaving you with a dangerous mess to clean up. Even so, some glassware makers (like Zalto) say that when done correctly, using the dishwasher is fine—so be sure to read care instructions for your particular glasses.