combustible vs noncombustible

combustible

adj

  • Capable of burning. 

noun

  • A material that is capable of burning. 

noncombustible

adj

  • That will not readily ignite and burn. 

noun

  • Any substance that is not combustible. 

How often have the words combustible and noncombustible occurred in a corpus of books? (source: Google Ngram Viewer )