de ‧ con ‧ tam ‧ i ‧ nate /ˌdiːkənˈtæməneɪt, ˌdiːkənˈtæmɪneɪt/ BrE AmE verb [transitive]
to remove a dangerous substance from somewhere ⇨ contamination , contaminate :
It may cost over $5 million to decontaminate the whole site.
—decontamination /ˌdiːkəntæməˈneɪʃ ə n, ˌdiːkəntæmɪˈneɪʃ ə n/ noun [uncountable]