Explosive material in this publication (8)
I believe the answer is:
magazine
This clue is a double definition.
'explosive material in this' is the first definition.
(as in a magazine in a gun)
'publication' is the second definition.
(I know that magazine is a type of publication)
(Other definitions for magazine that I've seen before include "Reading matter" , "paper?" , "Section of a firearm" , "Storehouse for ammunition" , "Periodical publication" .)