noncombustible       
adjective  formal (also non-combustible) uk/ˌnɒn.kəmˈbʌs.tə.bəl/ /ˌnɑːn.kəmˈbʌs.tə.bəl/
 非可燃的,非易燃的
not able to burn easily
  The roofs have to be built from noncombustible materials.  屋顶须使用非可燃材料建造。 
 Put the liquids into a non-combustible container. 将液体放入不可燃的容器中。 
 - More examples
 - They did not install sprinklers because the building was made of noncombustible concrete.
 - The part next to the fire must be made of a non-combustible material.
 - Smoking is only allowed if you are standing on a non-combustible material.
 - The insurance company suggested that we should replace our old wooden roof with a new non-combustible one.