15 Items You Must Avoid Placing in Your Dishwasher

Let's talk about keeping your kitchen companions in top-notch shape. Sharp knives? It's better to hand wash them to avoid blade dulling. Delicate china and nonstick cookware? They're not dishwasher fans, treat them gently. 

Things to avoid placing in your Dishwasher

Appliance Giant guide suggests things not to put in dishwasher ensuring your kitchen sidekicks stay pristine, ready for a lifetime of cooking adventures without losing their charm. 

Sharp Knives

Sharp knives should be washed by hand instead of using the dishwasher because the dishwasher can dull their blades. Even if the manufacturer's instructions suggest it's safe to put knives in the dishwasher, there's a risk of cutting yourself while loading and unloading sharp knives. To stay on the safe side, it's best to hand wash them.

Nonstick Pans and Pots

Unless the manufacturer clearly says it's safe for the dishwasher, avoid putting nonstick cookware in there. Dishwashing can wear down the nonstick coating over time, leading to flakes during cooking and ruining the nonstick surface.

Hollow-Handled Knives

The dishwasher’s high temperatures can melt the adhesive bonding between the two parts of a hollow-handled knife, causing the handle to come apart. To maintain their integrity, it's best to hand wash these knives.

China with Metallic Decoration

Surprisingly, many porcelain and china dishes can go in the dishwasher without a problem. However, if your dinnerware has metallic designs or trim, it's better to hand wash to avoid damaging the decorations. Also, be cautious about chipping by loading the dishwasher carefully to prevent accidental knocks between dishes.

Cast Iron

Never put cast iron in the dishwasher. It takes a while to develop a nonstick surface on cast iron, and dishwasher detergents can strip it away, making the pan prone to rust. Stick to using plain water and nonabrasive sponges for cleaning. If you take good care of your cast iron cookware, it can last for generations.

Pressure Cooker Lids

Avoid putting pressure cooker lids, whether for stovetop or electric ones like the Instant Pot, in the dishwasher. Dishwasher detergent or bits of food could get stuck in the regulator or safety valves. It's better to hand wash the tops, gaskets, and pots in warm, soapy water. Ensure thorough rinsing and drying. Don't store the lid in place, as the gasket might seal permanently, risking the loss of the pot.

Milk Glass

If you run semi-opaque milk glass dishes through the dishwasher frequently, the milky white color may end up turning yellow. To be on the safe side, it's better to hand wash these items.

Hand-painted Ceramics and Stoneware

Preserve the beauty of hand-painted ceramics and stoneware by hand-washing them. Avoid risking the artwork fading away over time if you want to enjoy its aesthetic appeal for longer.

Antiques and Other Delicate Items

Avoid putting delicate items like hand-blown glass, antiques, and fine figurines in the dishwasher. If it's priceless or a family heirloom, give it the care it deserves by hand washing.

Aluminium Cookware

Dishwasher hot water can stain aluminium and harsh detergents dull its finish. Avoid putting even disposable aluminium pie pans in the dishwasher, as they can mark other items. Check the manufacturer's instructions for stainless steel cookware; rinse if not running the dishwasher soon.

Acrylic Dishwasher

Hot water and strong dishwasher products can harm acrylic plates, leading to hairline cracks and fading imprints. Preserve their appearance by hand washing these items to keep them looking new.

Printed Measuring Cups

For measuring cups with markings on the side, it's best to hand wash. Dishwasher detergent can gradually erase the measurements, making them useless for accurate measuring over time.

Plastic Items

Unless explicitly labelled as "dishwasher safe," avoid putting plastic items in the dishwasher. If they are marked as such, place them on the top rack only to prevent the heating element from melting or warping them.

Insulated Pitchers, and Travel Mugs

To safeguard the vacuum seal, refrain from using the dishwasher for insulated pitchers, drinkware, and travel mugs. Hand washing is the optimal method to preserve their effectiveness and longevity.

Dishes with Substantial Food Remnants

Large pieces of food can clog the dishwasher drain or stick to clean dishes. While you don't need to rinse dishes, it's a good idea to scrape off excess food before loading them.


As your trusted appliance giant guide, we hope these insights help you navigate what not to put in a dishwasher in your kitchen. From sharp knives to antique treasures, a mindful approach to dishwashing ensures your essentials endure, promising a kitchen filled with enduring charm.