From 1949 through to 1969 they were served in fiberboard boxes which were thrown out when the passenger had finished with them. In 1970 the TRA changed to aluminum boxes, but later medical studies proved that the aluminum was toxic, and thus unsuitable for use with food.
五十九年起改用鋁盒便當，後來鋁製品經醫學研究證明有毒，不適合做食用器皿。