Annotation. The material provides data on toxicological and hygienic assessment  new cotton defoliant "UzDEF-K." It was found that the preparat is a low-hazard compound belongs to IV class of danger. Designed hygienic standards in the environment and food products (MPC in water bodies of water , in the air of the working area and the atmosphere air; MRLs in food, soil UEC ) . Science-based regulations of safe use of the drug in the agrifarms - sanitary protection zone, time-to-work.

Keywords: pesticide, hygienic standard, defoliant " UzDEF-K", the environment, water, air, soil, food products.