Use fan improperly, creating hazard (6)
I believe the answer is:
unsafe
'creating hazard' is the definition.
'use fan improperly' is the wordplay.
'improperly' is an anagram indicator (I've seen this in other clues).
'use'+'fan'='usefan'
'usefan' with letters rearranged gives 'UNSAFE'.
(Other definitions for unsafe that I've seen before include "Hazardous" , "Dangerous - legally without basis" , "Not reliable, dangerous - perhaps a legal conviction" , "Precarious" , "giving no protection" .)