Collocations for toxic - adj.

be, prove, stay
Black walnuts can prove toxic to other plants.

become
remain

extremely, fairly, very, etc.
highly, particularly
potentially
potentially toxic chemicals

to
This chemical is toxic to many forms of life.

Toxic is used with these nouns:
chemical, compound, effect, emission, fumes, gas, ingredient, material, metal, mould, pesticide, pollutant, pollution, side effect, substance, waste