biodegradable vs decomposable

biodegradable

adj

  • Capable of being decomposed by biological activity, especially by microorganisms. 

noun

  • Any material that can be decomposed by biological activity. 

decomposable

adj

  • Able to be decomposed 

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