13 items you should never put in the dishwasher, according to experts

Using the dishwasher can be a convenient way to clean dishes and utensils. However, not all items are dishwasher-safe. Putting the wrong things in the dishwasher can lead to damaged and ruined dishware. According to cleaning experts, there are several items you should avoid putting in the dishwasher.

Wooden Utensils and Cutting Boards

The high heat and harsh detergents used in dishwashers can cause wood to crack, warp, and lose its finish. It’s best to hand wash wooden spoons, spatulas, cutting boards, and other utensils. Use warm, soapy water and dry thoroughly to protect the wood. Prolonged exposure to water can cause wood to deteriorate.

Hand-Painted Dishware

The artwork on hand-painted plates, bowls, mugs, and other dishware is usually not dishwasher-safe. The combination of hot water, strong detergents, and turbulence during the wash cycle can cause paints and colors to fade and run. Protect handmade art by washing these items by hand.

Cast Iron Cookware

While cast iron is an extremely durable material, it can rust if exposed to a lot of moisture. Handwashing cast iron pans helps protect the seasoning. If you do put cast iron in the dishwasher, avoid using detergent and immediately dry the pan thoroughly after the cycle finishes to prevent rusting.

Fine Crystal and Stemware

The intense heat and high water pressure in a dishwasher can lead to chipping and breaking of delicate crystal and stemware. The turbulence can cause thin glass to hit other items, leading to cracks and scratches. Handwashing your fine glassware reduces the risk of damage.

Antique China Dishes

Vintage and antique china usually has delicate patterns and gold trim accents. The colors and finishes aren’t designed to withstand a dishwasher’s harsh effects. Detergents can fade decorative patterns. Gold edging can discolor or peel away. It’s safer to gently hand wash these decorative and collectible dishes.

Non-Stick Pans and Bakeware

The non-stick coating on pans and bakeware can deteriorate when subjected to a dishwasher’s high heat drying cycle. It’s better to wash these by hand to preserve the non-stick surface. Avoid abrasive scrubbers and instead use soft cloths, sponges, or brushes.

Kitchen Knives

Dishwasher detergent is highly alkaline and can react with metal knife blades. The harsh environment inside a dishwasher can cause pitting and corrosion on knife surfaces. Handwashing helps maintain sharp cutting edges and preserve the handles. Never put good kitchen knives in the dishwasher.

Non-Dishwasher Safe Plastic Items

Look for the manufacturer’s markings on plastic dishware and utensils. Many are not rated as dishwasher-safe. The heat can warp and melt plastic. Brittle plastics can crack or break. Handwashing is gentler on plastic. Avoid extremely hot water and let plastics air dry.

Insulated Drinkware

Water bottles, travel mugs, and insulated drinkware have inner linings and seals that can fail in high dishwasher heat. Moisture can get trapped inside and breed mold and bacteria. Stainless steel drinkware holds up best, but handwashing is still recommended for insulated containers.

Decorated Mugs and Glasses

The graphics, decals, and painted designs on mugs, glasses, and dishware are vulnerable in the dishwasher. The combination of hot temperatures, high pressure spray, and harsh detergents can cause the decorative elements to fade, peel, or scratch off.


Aluminum reacts to the caustic detergents used in dishwashers. Prolonged exposure can cause corrosion and pitting of the surface. Anodized aluminum finishes offer more protection, but handwashing is still gentler for maintaining aluminum cookware.

Sterling Silver and Silver Plate

Sterling silver and silver-plated items can become discolored and tarnished from dishwasher detergents. The high heat dries out natural protective oils. Silver develops a patina or film. Use a silver polish and soft cloth to hand wash these items. Avoid abrasive scrubbers.

Electronics and Appliances

Never put electronics in the dishwasher. The water can damage sensitive circuits and wiring. Appliances like food processors, mixers, and electric knives have electrical components that can malfunction when washed in the dishwasher. Only use a damp cloth to clean the exteriors by hand.

The Bottom Line

Regardless of convenience, some dishware, utensils, and cookware should always be handwashed. Check manufacturer instructions for proper care. When in doubt if an item is dishwasher-safe, err on the side of caution and wash by hand to extend its lifespan. Being selective about what goes in the dishwasher prevents damage.

Frequently Asked Questions

Why shouldn’t you put wood in the dishwasher?

The combination of hot water, harsh detergents, and the tumbling action can cause wood to crack, warp, and deteriorate over time. Handwashing is gentler on wood.

What types of dishes should not go in the dishwasher?

Hand-painted dishes, antique china, crystal stemware, cast iron, non-stick pans, and decorative mugs/glasses with decals should be handwashed instead of putting them in the dishwasher.

Can you put plastic containers in the dishwasher?

Some plastic containers are dishwasher-safe, but many are not. The heat can warp plastic and cause it to melt. Check manufacturer’s instructions and opt for handwashing if unsure.

What happens if you put a knife in the dishwasher?

The harsh detergent and hot water can corrode knife blades. Prolonged dishwasher use will ruin the sharp cutting edge. Handwashing is best for all fine cutlery and kitchen knives.

Can insulated water bottles go in the dishwasher?

No, the hot temperatures and moisture in a dishwasher can damage the inner seals of insulated drinkware. Also, water gets trapped inside, creating an environment for mold. Handwashing is recommended.


Being mindful and selective about what gets loaded into the dishwasher will save you money in the long run by preventing needless damage to dishware, glassware, and valuables. Follow the manufacturer’s care instructions, and when in doubt, opt for gentle handwashing for items you care about and want to protect.