10 items that should never go in your dishwasher

How do you know something is dishwasher safe?

There’s no standard definition for ‘dishwasher safe’, but generally it means items that can withstand hot temperatures, spraying water and detergents.

Most products will list on their packaging and on the items themselves if they’re dishwasher safe. But they don’t always use words. There might just be an image of a dishwasher, and as long as the logo isn’t crossed out, then it is dishwasher safe.

There are no standard icons, but look on the bottom of the item an image like:

Your rights when dishwasher safe items are damaged in the dishwasher

If you have bought a product that claims to be dishwasher safe, and it’s damaged in the dishwasher, you can take it back to the retailer and claim under the Consumer Guarantee’s Act (CGA).

But first you need to make sure you have followed all the correct washing instructions.

• Did you wash the item on a regular cycle, not a super-hot wash (for pots and pans only)?

• Did you use the correct amount of detergent?

• Did you place the item in the correct place in the dishwasher?

Your rights under the CGA

• Major damage: If you followed the washing instructions for both your dishwasher and the item and the item is damaged so it can’t be used anymore, such as a container warping out of shape, then you could claim it’s a major fault and ask for a repair, refund or replacement from the retailer.

• Minor damage: If it’s only minor damage, then it’s up to the retailer to determine how it will remedy the issue, but you are still covered by the CGA.

See our article on the Consumer Guarantees Act for more information about your rights.

Dishware you should never put in your dishwasher

1. Silver: Sterling or plated silver should never go in the dishwasher as it tarnishes easily, usually due to the detergents, and polishing may not remove the stain.

2. Fine china: Depending on the age and condition of your china and gold-trimmed crockery, putting it in the dishwasher can wear away the pattern or chip and break the dishes.

3. Crystal and fine glassware: Sensitive to temperature and detergents, these types of delicate glassware are prone to cracking and etching, which is irreversible.
   Note: Crystal can turn cloudy from the build-up of calcium deposits from hard water. Try cleaning cloudy crystal with a lime remover as it may not be etched.

4. Wooden cooking utensils and chopping boards: These can warp and crack from repeated washes in the dishwasher.

5. Utensils with wood or bone handles: Temperatures and detergent can weaken the glue holding on the handle, causing it to fall off.

6. Cast-iron cookware: The harsh action of the dishwasher can strip the cookware’s seasoning (the non-stick surface that builds up over time with cooking) and eventually cause the iron to rust.

7. Copper pots and pans: The dishwasher detergents can discolour the cookware, which will take a lot of hard hand cleaning to restore.

8. Brass: The hot temperature in a dishwasher can cause a chemical reaction that eats away at the protective layer on brass, which you can only restore by polishing with a brass polish.

9. Items with labels on them: The dishwasher might seem like a good way to remove sticky jar labels, but the label just ends up stuck in the dishwasher filter and can cause headaches down the track.

10. Thermos/insulated flask: this includes the insulated food containers such as those made by Frank Green, the heat of the dishwasher can cause damage to the insulation and seals. Some may be dishwasher safe, but it’s best to not put them in the dishwasher.

Double-check if these items are dishwasher safe before you stack them up!

• Aluminium: While some aluminium items are dishwasher safe, dishwasher detergents can cause damage to some aluminium products, so check your item’s cleaning instructions first.

• Non-stick cookware: Some manufacturers say their non-stick cookware is dishwasher safe. However, the dishwasher is likely to wear down the non-stick coating. Always check the packaging first for washing instructions and the bottom of the cookware for a dishwasher safe icon.

• Lunchboxes: Quite a few materials are used in making different lunchboxes. Some aren’t safe for dishwashers, so check the bottom of the lunchbox for a dishwasher safe icon.

• Water bottles: Some plastics in drink bottles aren’t dishwasher safe as they can’t stand the high temperatures, so it’s best to check the bottom of the bottle for a dishwasher safe icon before throwing the bottle in the dishwasher.

• Air fryer parts: Depending on your model, some air fryer parts, such as the basket, may be dishwasher safe, but check the manual first!

• Plastic plates: Some plastic plates can go in the dishwasher, but only on the top shelf, where it is cooler.

Items that can go in the dishwasher

• There are plenty of items that are perfectly fine to go in the dishwasher, but it always pays to check for a dishwasher safe icon first.

• Plates (crockery) – anything metal rimmed should be hand washed

• Drinking and wine glasses

• Cups – beware of handmade pottery

• Hard plastic – thin (less than 5mm) should probably be hand washed

• Ceramic

• Silicone

• Stainless steel

• Stoneware

• Plastic cutting boards

• Cookware – for cast-iron, copper, aluminium and non-stick cookware see below.

• Ceramic baking dishes

• Enamel-ware

• Coffee plunger

• Exhaust fan filters and covers

• Oven racks

• Baby bottles

• Bath toys

• Breast pump parts – check the instructions

Use the top rack for delicate items

Some kitchenware and utensils come with instructions saying to wash in the top rack only. This is because the top rack of a dishwasher is typically cooler during a hot wash than the bottom rack due to where the heating element is situated.

Use the cutlery tray if you have one

Cutlery trays are a safer and more organised alternative to the cutlery basket (it’s easier to avoid sharp knife blades when unloading if your cutlery is laid down). They also free up more space in the bottom basket for your plates. Often located just above the top rack, they are easily accessed and often removable. But they are generally out of sight (check if your dishwasher has one that you didn’t know about!). If you can’t decide whether you like the tray or basket best, see what our staff had to say in our article Dishwasher cutlery: tray or basket?

How to stack your dishwasher

Now you know what should and shouldn’t go in your dishwasher, you can cut down on household arguments and know where to put the dishes in the dishwasher from our article How best to stack your dishwasher.