Salt container has broken (6)
I believe the answer is:
potash
'salt' is the definition.
(type of salt)
'container has broken' is the wordplay.
'container' becomes 'pot' (pot is a kind of container).
'broken' indicates an anagram.
'has' with letters rearranged gives 'ash'.
'pot'+'ash'='POTASH'
(Other definitions for potash that I've seen before include "Alkaline compound" , "Powerful alkali used in gardening" , "feed in bed?" , "Potassium carbonate or hydroxide" , "Compound used in agriculture and industry - shop at (anag)" .)