10 May 2025 6 Things You Should Never Put on the Bottom Rack of Your Dishwasher

See the full article in The Spruce

By Sarah Lyon

Key Takeaways:

• Plastic containers, lids, and cutting boards can all warp or melt in the bottom rack since that’s where the cycle is the most intense.
• Hand wash or place silicone kitchen items in the top rack since dishwasher detergent can leave a chalky residue behind.
• Avoid placing any sharp knives on the bottom rack to prevent any injuries and them from getting dull.

While having a dishwasher in your kitchen is certainly ultra convenient on a day-to-day basis, not all commonly used cooking items are meant to be cleaned this way—or at least do not belong on the dishwasher’s bottom rack. To ensure the longevity of your go-to cooking tools, we’ve spoken with three cleaning experts and asked them to share a handful of kitchen items that will suffer if placed on the bottom dish rack.

Here, our experts provide input on the best way to clean these items so they’ll last for years to come, whether that means placing them on the dishwasher’s top rack or hand washing them.

Plastic Containers and Lids

Tupperware is meant to last you for years on end, and you’d like to use your plastic pieces time and time again, be sure not to place them on the bottom rack of the dishwasher.

“Even if they’re labeled dishwasher-safe, plastic can warp or melt on the bottom rack where the heat is most intense,” Robin Murphy, the founder of Maid Brigade, says.

Always be sure to clean these items on the top rack, where they’ll be safe.