Unstable nitrates - central ingredient of explosive to produce slates (5,4)
I believe the answer is:
tears into
'produce slates' is the definition.
The answer and definition can be both to do with contact as well as being verbs in their -s form.
Perhaps there's a link between them I don't understand?
'unstable nitrates central ingredient of explosive' is the wordplay.
I cannot really understand how this works, but
an anagram of 'nitrates' is 'tearsint' which is within the answer.
'of' could be 'o' and 'o' is found within the answer.
No letters remain.
This explanation may well be incorrect...
'to' is the link.
Can you help me to learn more?
(Another definition for tears into that I've seen is " attacks".)