The purpose of this study was to develop indicators, which are low cost and user-friendly, for warning temperature rising in cold chain. The color of Food Blue No.2 in glycerol aqueous solution changed from blue to light yellow. To apply this behavior, the aqueous solution was packed into transparent plastic bag with various concentration of glycerol. An indicator containing 0.01% Food Blue No.2 in 60% glycerol warned by changing color after 135 hours at 4℃. An indicator containing 0.01% Food Blue No.2 and 0.01% Food Red No.2 in 60% glycerol warned by changing color after 156 hours at 4℃. As a result, it showed that an ability to develop a new type indicator using Food blue No.2
