Is Styrofoam cup dishwasher safe?
Not dishwasher safe
No, Styrofoam cups are not dishwasher safe.
Quick facts
| Dishwasher safe? | No — Not dishwasher safe |
|---|---|
| Category | Containers |
| Source | Researched — confirmation in progress |
| Last checked | 2026-06-17 |
Why
Styrofoam (expanded polystyrene) is not heat-resistant and can melt or warp in the high temperatures of a dishwasher. The hot water and drying cycle can cause the cup to deform or break down, potentially releasing chemicals.
How do you wash Styrofoam cup?
Hand wash with mild soap and cool water, then air dry. Avoid hot water or abrasive scrubbers.
More containers
Last updated 2026-06-17. General guidance — always check your product’s care label. How we verify.