The damage: Peeling, flaking, or scratched coating that sticks to food and may be toxic if ingested.
What to do instead: Wash non-stick pans by hand with warm, soapy water and a soft sponge. Avoid abrasive scrubbers. Dry immediately.
Pro tip: Use silicone, wood, or plastic utensils to avoid scratching the coating.
6. Insulated Mugs and Thermos Bottles (Lose Insulation)
Why it’s bad: Many insulated mugs and thermoses have a vacuum seal between two walls of metal or plastic. The high heat can break the seal, ruining the insulation.
The damage: The mug or thermos will no longer keep drinks hot or cold. Condensation may form on the outside. The seal may be permanently compromised.
What to do instead: Wash by hand with warm, soapy water and a bottle brush. Rinse thoroughly. Dry with a towel.
Pro tip: Check the manufacturer’s instructions. Some high-end brands (like Yeti) claim their products are dishwasher-safe, but hand-washing extends their life.
7. Copper, Bronze, or Brass Items (Discolor)
Why it’s bad: The harsh detergents react with these metals, causing discoloration, tarnishing, or pitting.
The damage: Dark spots, greenish film, or uneven patina that is difficult or impossible to remove.
What to do instead: Wash by hand with warm, soapy water and a soft cloth. Rinse and dry immediately. Use a specialized metal polish to maintain shine.
Pro tip: For heavy tarnish, use a paste of lemon juice and salt, then rinse and dry.
8. Delicate Glassware (Etches and Breaks)
Why it’s bad: The high heat and harsh detergents can etch delicate glass (especially hand-blown or antique). The water pressure and jostling can cause chipping and breakage.
The damage: Cloudy film, rough texture, chips, cracks, or complete breakage.
What to do instead: Wash delicate glassware by hand with warm water and a mild detergent. Use a soft cloth or sponge. Rinse with cool water. Dry with a soft, lint-free towel.
Pro tip: Place a towel in the bottom of the sink to cushion glassware. Never stack glasses while washing.
Bonus: The Dishwasher Itself (What Not to Do)
Don’t overload the dishwasher. Overloading prevents water and detergent from circulating properly, leading to poor cleaning and potential damage to items.
Don’t use too much detergent. Excess detergent leaves residue on dishes and can etch glassware.
Don’t leave food particles on dishes. Large food particles can clog the filter and spray arms. Scrape, don’t pre-rinse (modern dishwashers are designed to handle residue).
Don’t block the spray arms. Large items (cutting boards, baking sheets) can block water flow. Place them on the sides or bottom rack.
Don’t put dishwasher-safe plastics on the bottom rack. Plastics are better on the top rack, where the heat is lower.