Tin can so explosive, permit needed (8)

I believe the answer is:

sanction

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'permit needed' is the definition.
I can't tell whether this defines the answer.

'tin can so explosive' is the wordplay.
'explosive' is an anagram indicator.
'tin'+'can'+'so'='tincanso'
'tincanso' is an anagram of 'SANCTION'.

Can you help me to learn more?

(Other definitions for sanction that I've seen before include "Go-ahead" , "Officially approve" , "Give authority or permission to" , "Give approval to, authorise" , "Permit - punishment for breach of treaty" .)

I've seen this clue in The Sun.

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