Toxicological Hazards of Herbicides Bromoxynil and Ioxynil

The title herbicides are selective post-emergent contact herbicides currently widely used in the EU and USA to control broad-leaved weeds especially in crops. They are typical inhibitors of photosynthesis acting simultaneously as uncouplers of oxidative phosphorylation. The review briefly discusses their physical and chemical pro¬perties, mode of action, degradation and toxicity. Bromoxynil and Ioxynil are of low-to-moderate toxicity for all the tested species, with no in vivo genotoxicity. Their main metabolites in microbial degradation are the corresponding acids and amides, which are supposedly less toxic.