Fire-resistant material (8)
I believe the answer is:
asbestos
'fire-resistant material' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for asbestos that I've seen before include "I might end up lagging" , "Heat-resistant fibrous mineral" , "condemned building material" , "'Fireproof substance, dangerous to health (8)'" , "Boss set a non-burning material up" .)