This part of GB/T 31270 specifies the basic requirements for materials, conditions, operation, quality control, data processing, test reports, etc. for acute toxicity test of chemical pesticides on fish.
This part applies to fish acute toxicity test for the registration of chemical pesticides. It may be used as reference for other types of pesticides.
This part does not apply to volatile and insoluble chemical pesticides.
2 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1
median lethal concentration
concentration of the test substance, at which 50% of the test organisms die in the acute toxicity test, expressed by LC50
Note: the unit is mg a.i./L.
2.2
test substance
substance to be tested
2.3
chemical pesticide
pesticide made of chemical substances through artificial synthesis, for some, the active substances in natural products are used as the mother body, and then subjected to imitation, structural transformation and innovation, they are bionic synthetic pesticides
Synonym: synthetic organic pesticide.
[Definition 2.3.1, NY/T 1667.1-2008]
2.4
technical material
final product consisting of the active ingredients and impurities obtained during the manufacturing process, which shall not contain visible foreign substances or any additives, and if necessary, a small amount of stabilizer may be added
[Definition 2.5.1, NY/T 1667.2-2008]
2.5
formulation
product stable in use and made of technical material (or technical concentrate) of pesticides and auxiliaries
[Definition 2.4, NY/T 1667.2-2008]
2.6
active ingredient; a.i.
specific chemical ingredient that is biologically active in a pesticide product
[Definition 3.1, NY/T 1667.2-2008]
2.7
static test
test liquid is not replaced during the test
2.8
semi-static test
test liquid is replaced at regular intervals (e.g. 24h) during the test to keep the concentration of the test liquid not lower than 80% of the initial concentration
2.9
flow-through test
test liquid is continuously updated during the test
2.10
reference substances
chemical substance or mixture used in a test to confirm or deny certain characteristics of a test substance or to judge the effectiveness of a test system
3 Test overview
There are three methods for determining fish acute toxicity: static test, semi-static test and flow-through test. Appropriate method shall be selected depending on the nature of the test substance. Different concentrations of the test substance liquids are prepared separately. The toxicity symptoms and death count of test fish are observed and recorded every day during 96h test period to calculate LC50 and 95% confidence limits at 24h, 48h, 72h and 96h.
