International organisation college brought in regarding waste (3,5)
I believe the answer is:
red cross
'international organisation' is the definition.
(I've seen this before)
'college brought in regarding waste' is the wordplay.
'college' becomes 'c'.
'brought in' indicates putting letters inside.
'regarding' becomes 're' (re can mean regarding, concerning).
'waste' becomes 'dross' (dross is a kind of waste).
're'+'dross'='redross'
'c' inserted within 'redross' is 'RED-CROSS'.
(Other definitions for red cross that I've seen before include "organisation offering aid" , "International humanitarian organisation" , "International relief organisation" , "that brings relief!" , "International team" .)