noun
styrofoam; expanded polystyrene
Commonly used for packaging, insulation, and craft materials. Often called 発泡スチロール in everyday Japanese, though technically a trademark.
壊れ物を送るので、発泡スチロールで包んだ。
I wrapped the fragile item in styrofoam before sending it.
発泡スチロールの箱に魚を詰め
We pack the fish in styrofoam boxes and ship them.