Ecotoxicity research and environmental hazard assessment of pesticides

Investigating the ecotoxicological properties of new pesticide formulations and assessing their hazard to non-target environmental organisms is crucial when deciding whether to introduce them into agricultural practice. The procedure for assessing the potential environmental hazards of pesticides, as well as the requirements for their state registration in Ukraine, are regulated by relevant legislation, regulations and guidelines. Aim. To summarize the basic requirements for ecotoxicological studies and the hazard assessment of pesticides for non-target environmental test organisms, and to determine the hazard classes of new pesticide formulations for terrestrial and aquatic organisms. Materials and Methods. This study involves a scientific analysis of EU and Ukrainian regulatory documents on ecotoxicological studies, focusing on the scope of toxicological testing based on the purpose of plant protection products. It assesses the acute toxicity and potential risk of pesticides to non-target environmental organisms. The methodology is based on OECD-recommended procedures for determining the acute ecotoxicity of pesticides and other chemicals in both aquatic and terrestrial environments. Results. The main OECD-recommended requirements for conducting ecotoxicological studies are outlined. Criteria for assessing acute and chronic toxicity in non-target organisms are presented, along with key approaches for evaluating the potential risk of pesticides using toxicological endpoints and indices that combine exposure and effect. The acute toxicity of nine new pesticide formulations was assessed for soil microorganisms, earthworms, bees, birds, daphnia, algae, and fish. The preparations Torsida, EC; President, SC; Gotika, SC; and Boxer, SC were found to be highly toxic to fish, daphnia, and bees, primarily due to the presence of pyrethroids and neonicotinoids. Among the studied products, the desiccant Scorpion Maxi, SL—based on diquat dibromide—was the most toxic to algae, owing to its selective phytotoxic effects. Conclusions. 1.The primary requirements for ecotoxicological studies and the assessment of pesticide hazards to non-target test organisms are summarized. The scope of ecotoxicological evaluation for plant protection products depends on their intended use, environmental exposure, and application conditions. To ensure consistency and reliability of test results, standardized OECD methods must be applied, along with adherence to GLP rules, regulations, and guidelines. 2. Among the tested products, the most toxic (hazard class Acute 1) are the insecticides Torsida, EC; President, SC; Gotika, SC; and Boxer, SC. The most sensitive species to these formulations are fish, crustaceans, and bees, which correlates with the presence of pyrethroids and neonicotinoids. 3. For algae, the most toxic product (hazard class Acute 1) is Scorpion Maxi, SL, based on diquat dibromide, consistent with its mode of action. 4. For birds, soil microorganisms, and earthworms, all tested formulations fall under hazard class 3 or are unclassified, except for Boxer, SC and President, SC, which are categorized as hazard classes 1 and 2 respectively based on their acute toxicity to earthworms.