1989 the state environmental protection administration presided over the formulation of the experimental criteria for safety evaluation of chemical pesticides. The standard divides pesticide registration data into "necessary data", "basic data" and "additional data". The basic physical and chemical properties, environmental behavior characteristics and toxic and side effects of pesticides on environmental organisms belong to "necessary information".
The Experimental Criteria for Safety Evaluation of Chemical Pesticides also adopts the grade method when evaluating the environmental behavior and environmental toxicity test results of pesticides.
For example, in the evaluation of environmental behavior test results, pesticide residues in soil are divided into three grades, pesticide mobility in soil is divided into five grades, and pesticide volatility from water is divided into three grades.
When evaluating the environmental toxicity test results of pesticides, the acute oral toxicity of pesticides to birds, the contact toxicity to bees, the contact toxicity to earthworms and the contact toxicity to fish and Daphnia were divided into three grades.
Regarding the toxicity classification of soil microorganisms, the guidelines stipulate that when the dosage of pesticides in soil is 1mg/kg, pesticides that inhibit the respiration of soil microorganisms by more than 50% within the range of 15d are highly toxic pesticides; When the dosage of pesticides in soil is 10mg/kg, the pesticides whose respiratory inhibition rate is less than 50% within15 days are low toxic.
The outstanding advantage of the classification model lies in its simplicity, which enables people to make a clear judgment on pesticides on the basis of limited data. In the evaluation of ecological security, the main deficiency of this model is that it fails to include the difference between pesticide consumption and field environmental behavior, so its evaluation results may sometimes be different from the actual situation in the field.