For many homeowners, the dishwasher is one of the most convenient appliances in the kitchen. It saves time, conserves water, and makes cleanup effortless. However, not everything is safe to wash in a dishwasher.
Stories of glass shattering during or after a wash cycle are uncommon but can happen, especially when certain types of glassware or cookware are exposed to repeated high heat and strong water pressure. While a dishwasher itself rarely “explodes,” broken dishes can scatter glass throughout the appliance, creating a dangerous mess.
Here’s what you should never put in your dishwasher—and how to keep both your dishes and your appliance safe.
Can a Dishwasher Really “Explode”?
In most cases, the dishwasher doesn’t actually explode.
Instead, one or more glass items may suddenly shatter during the hot wash or drying cycle due to:
- Thermal stress from rapid temperature changes
- Tiny chips or cracks that weaken the glass
- Manufacturing defects
- High-pressure water jets striking delicate items
Tempered glass, although designed for safety, can occasionally break unexpectedly if it has been damaged.
10 Things You Should Never Put in the Dishwasher
1. Crystal Glassware
Crystal is delicate and can become cloudy, chipped, or cracked after repeated dishwasher cycles.
Always wash crystal by hand using warm water and a mild detergent.
2. Thin Wine Glasses
Stemware can easily break when bumped by other dishes or exposed to strong water pressure.
Hand washing is the safest option.
3. Wooden Utensils and Cutting Boards
Dishwashers can cause wood to:
- Crack
- Warp
- Split
- Lose its finish
Wash wooden items with warm soapy water and dry immediately.
4. Cast Iron Cookware
Dishwasher detergent strips away the seasoning that protects cast iron from rust.
Instead:
- Wash with hot water.
- Dry thoroughly.
- Apply a light coat of cooking oil.
5. Sharp Kitchen Knives
Dishwashers can:
- Dull the blade
- Damage the handle
- Increase the risk of injury when unloading
Wash quality knives by hand.
6. Nonstick Pans (Unless Dishwasher Safe)
Although many newer pans are labeled dishwasher safe, frequent dishwasher use may shorten the life of the nonstick coating.
Hand washing helps preserve performance.
7. Aluminum Cookware
Harsh detergents can discolor aluminum, leaving it dull or spotted.
Some aluminum may even react with dishwasher chemicals.
8. Copper Pots and Pans
Copper loses its shine in the dishwasher and may develop discoloration.
Use a gentle hand wash and polish occasionally.
9. Insulated Travel Mugs
Many insulated cups have a vacuum seal that can be damaged by high dishwasher temperatures.
Unless labeled dishwasher safe, wash by hand.
10. Antique or Hand-Painted Dishes
Decorative finishes and painted designs may fade or peel after repeated dishwasher cycles.
These valuable pieces should always be cleaned by hand.
Tips to Prevent Glass Breakage
If you wash glassware in your dishwasher:
- Place glasses securely so they don’t touch.
- Avoid overloading racks.
- Use the appropriate rack for delicate items.
- Allow hot glassware to cool before exposing it to cold water.
- Replace chipped or cracked glasses.
Even tiny imperfections can weaken glass over time.
Dishwasher Safety Tips
To keep your dishwasher operating safely:
- Inspect racks for broken or rusted tines.
- Clean the filter regularly.
- Use only dishwasher detergent.
- Never overload the machine.
- Follow the manufacturer’s loading instructions.
- Check glassware for damage before each wash.
What Should You Do If Glass Breaks Inside?
If glass shatters during a wash cycle:
- Turn off the dishwasher.
- Allow everything to cool.
- Wear protective gloves.
- Carefully remove large pieces.
- Vacuum or wipe up tiny fragments.
- Inspect the filter for broken glass.
- Run a rinse cycle after cleaning.
Never reach blindly into the dishwasher after glass has broken.
Final Thoughts
A dishwasher is a valuable kitchen appliance, but it’s not designed for every type of cookware or glassware. Delicate crystal, wood, cast iron, sharp knives, and certain metals are best washed by hand to avoid damage and extend their lifespan.
By loading your dishwasher correctly and knowing which items to keep out, you can prevent accidents, protect your favorite kitchen tools, and enjoy worry-free cleaning for y
