In 1979, lightweight polystyrene boxes took over from stainless steel, mostly because once the passengers had finished their lunches, they'd usually end up taking the box with them, and when using the stainless steel boxes, this was at a considerable cost to the TRA. Secondly, passengers had complained that the lunchboxes weren't sufficiently clean, with bits of rice stuck on them, about which word quickly spread.
民國六十八年，輕便的保麗龍盒取代了不鏽鋼飯盒，主要是旅客吃完便當後往往順手把不鋼盒帶走，造成鐵路局不小的損失；其次，有旅客反映，飯盒沒有清洗乾淨，米粒殘渣還留在上面，一度也造成話題。