touchpapertouch‧pa‧per /ˈtʌtʃˌpeɪpə $ -ər/ noun [countable] British English 
a piece of special paper that burns slowly, used in order to start a firework burning: 
Light the blue touchpaper, then move to a safe distance.
a piece of special paper that burns slowly, used in order to start a firework burning: Light the blue touchpaper, then move to a safe distance.