Chemical at shop exploded (6)
I believe the answer is:
potash
'chemical' is the definition.
(I've seen this before)
'at shop exploded' is the wordplay.
'exploded' indicates anagramming the letters.
'at'+'shop'='atshop'
'atshop' is an anagram of 'POTASH'.
(Other definitions for potash that I've seen before include "chemical compound" , "Agricultural chemical" , "Potassium compound used as fertiliser" , "Compound used in agriculture and industry - shop at (anag)" , "Caustic stuff" .)