Starts to analyse several potential hazards associated with key waterproofing material (7)
I believe the answer is:
asphalt
'waterproofing material' is the definition.
'starts to analyse several potential hazards associated with key' is the wordplay.
'starts to' indicates taking the first letters.
'associated with' says to put letters next to each other.
'key' becomes 'alt' (I've seen this in other clues**).
The first letters of 'analyse several potential hazards' is 'asph'.
'asph'+'alt'='ASPHALT'
(Other definitions for asphalt that I've seen before include "Bitumen" , "Road-surfacing material" , "petroleum residue" , "Pitch surface" , "Road surface material" .)