Surprising items you can and can't put in the dishwasher

Obviously plates, mugs and cutlery can go in the dishwasher, but how about make-up brushes, refrigerator drawers and toothbrush holders?

There's a number of unexpected items you can clean in your dishwasher. But before you start throwing in anything and everything, there are certain items where hand washing is always best.

To help you work out what can and can't go in the dishwasher – and avoid having to replace items that aren't dishwasher-safe – we've put together a handy list of dos and don'ts.

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5 surprising things you can put in your dishwasher

1. Make-up brushes, plastic hairbrushes and combs

Make sure to use an eco or low-temperature delicate wash for your brushes and combs as a hot wash could damage them.

To protect the bristles, put them in the top rack with your glasses and mugs where the water pressure and temperature are lower.

If you're putting in your hairbrushes, make sure you remove any trapped hair first as it will tangle up and clog the filter, which is an extra job you don't want to be dealing with.

2. Plastic baby toys, bottles, dummies, cutlery and dishes

Many baby items can be cleaned in the dishwasher. Some models even come with high-heat programs specifically for this, often called 'Hygiene' or 'Baby Protect'. 

In some dishwashers, these programs combine an intensive wash with a rinse that includes a burst of higher temperature up to 70°C. In others, a higher temperature short-burst rinse finishes off a normal wash program.

These programs are often promoted as leaving dishes germ-free or sterilised. However, we wouldn't recommend that you rely on your dishwasher for sterilising items for very young babies. Use an alternative method instead. 

Clean more efficiently with our tips on how to load your dishwasher 

3. Refrigerator shelves and drawers

Thoroughly cleaning and drying your fridge shelves and drawers is a real chore. They're big and unwieldy, but if you can squeeze them into your dishwasher, you could save yourself the effort. 

You'll want to use a slightly cooler eco-wash, or even just a quick 30-minute one, to make sure the heat doesn't damage them.

For further advice on getting your fridge spotless, read our tips on how to deep clean your refrigerator. 

4. Toothbrush holders and soap trays

Water tends to collate at the bottom of a toothbrush holder or soap tray, and when combined with toothpaste or soap, it can leave these things looking pretty grim. Plus, bacteria can grow and fester in the hard-to-reach crevices. 

But cleaning them can be a fiddly and unwelcome job, so pop them in the dishwasher to remove all traces of grime. 

Again, go for the top rack to prevent any warping from high temperatures. 

5. Vacuum cleaner attachments

Dust-filled attachments can mean your vacuum cleaner doesn’t work as well as it used to. Cleaning these non-electricals can reinvigorate your vacuum, but it's often pretty tricky and messy to do by hand. You might also be able to remove the top rack of your dishwasher to get larger parts, such as the dust collection bin, to fit in.

We'd recommend you use a lower temperature or quick wash, again to prevent high heat warping the plastic. And less detergent than you'd use for a regular load will be fine, as a super-thorough clean shouldn't be necessary.

Check out our dishwasher tablet reviews to find the best detergent for your dishwasher

7 things you shouldn’t put in a dishwasher

1. Kitchen knives

While steel and ceramic knives are safe in the dishwasher and won't tarnish, the heat can make the blade more prone to dulling.

It's better to wash them by hand to avoid having to sharpen them more often – and it will ensure they last longer and stay in great condition. 

The same goes for blender blades, which can dull over time, meaning your drinks will be less smooth.

If your kitchen kit is due for an upgrade, discover the best knife sets, best hand blenders and best frying pans according to our tests.

2. Wooden spoons and chopping boards

Anything wooden – spoons, boards, chopsticks or serving bowls – can't go in the dishwasher. Regardless of what type of wood it is, the high heat of a dishwasher will cause it to splinter and split, and any cracks are ideal breeding grounds for bacteria.

Instead, wash wooden items by hand and avoid submerging them in water for a long time. A quick scrub and rinse should be fine, but for stains or lingering odours, you could try sprinkling some salt onto the board and scrubbing with half a lemon. 

3. Non-stick anything and some baking trays

Non-stick pans should be washed and dried by hand, as the dishwasher can wear down the non-stick surface over time. Your next omelette could be stuck to the pan if you don't stick to this advice.

Many people put their baking trays in the dishwasher so they don't have to scrub them clean. But check what yours are made of: stainless steel and anodised aluminium are fine but cast iron or regular aluminium will need hand-washing. 

To avoid getting a load of grease in your dishwasher – which could clog the pipes – wait for the tray to cool and for the fat to solidify. Then you can scrape it off with kitchen paper and put it in the bin, which is much better for your plumbing.

4. Crystal or milk glass

If you take all the right precautions, you can wash crystal in a dishwasher, but we wouldn't recommend it. Over time, abrasive detergents can mark and scar the crystal. Full-lead crystal is less dense than glass and scratches easily.

If you're adamant, choose a very mild detergent or look for one approved for crystal or cut-glass use. Place the crystal in the top rack of the dishwasher and make sure that the glasses do not touch one another. Then use a delicate cycle, which washes at a lower temperature to protect items.

As for milk glass, it can be chipped by knocking against other plates in the wash. The dishwasher may also cause discoloration, turning it slightly yellow over time.

Read dishwasher programs explained to help you to make the most of your appliance

5. Copper, aluminium or cast-iron cookware

The harshness of the dishwasher can cause any copper surfaces to dull, so to make sure your prized cookware keeps on shining, wash it by hand. 

And detergent can cause aluminium to tarnish and turn black. Only anodised aluminium is dishwasher-safe, as it has a protective layer of oxide. 

All cast iron will have a layer of protective, non-stick layer of baked-on oil known as seasoning. The dishwasher will wash this away, and the iron beneath will rust. Many cast iron pots and pans have a layer of enamel to make it easier for you to take care of them. But this can also wear down and dull in the dishwasher. Hob burners and grates are often made of cast iron, so avoid throwing these in. 

If you're not sure, it's better to be safe than sorry, so keep your Le Creuset out of the dishwasher.

6. Insulated coffee mugs or water bottles

The sustained high temperature of a dishwasher could damage the vacuum seal on insulated pitchers or reusable water bottles. 

This will make the insulation worse, preventing them from keeping your drinks hot or cool. It could also make them prone to leaking.

While some coffee cups and travel mugs can be popped into a dishwasher on the top shelf, others need to be washed by hand, so always check the packaging or the manufacturer's website.

7. Pressure cooker lids

While the actual pot of your pressure cooker can go in the dishwasher, never put the lid in. 

The high heat and water jets could damage the seal mechanism, making the actual pressure part of your pressure cooker obsolete. 

It could even make using your pressure cooker dangerous if the safety mechanisms are faulty.

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