GB/T 15670.3-2017Toxicological test methods for pesticides registration - Part 3: Acute oral toxicity test - Up-and-down-procedure (English PDF)

1 Scope

GB/T 15670.3-2017 is the Chinese national standard on toxicological test methods for pesticides registration - part 3: acute oral toxicity test - up-and-down-procedure, in the field of agriculture. The /T suffix marks it as a recommended standard: it is not compulsory by itself, but it becomes binding as soon as a contract, a tender or a customer specification calls it up - which in practice is how most foreign buyers meet it. It was issued on 12 July 2017 by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China; Standardization Administration of China, and has been in force since 1 February 2018. Classification: ICS 65.100, CCS B17. This page is published from the official record of the standard held by the Chinese standards administration: the identification, the dates, the classification and the issuing body are taken from there. The clause text, the tables and the numeric limits are in the document itself, which is delivered complete in English translation.

This part of GB/T 15670 specifies the basic principles, methods and requirements for the up-and-down-procedure of acute oral toxicity testing. This part applies to acute oral toxicity tests conducted for pesticide registration.

2 Normative references

The following documents are essential for the application of this document. For any dated referenced document, only the dated version applies to this document. For any undated referenced document, the latest version (including all amendments) applies to this document.

GB 14925 Laboratory animal - Environment and housing facilities Regulations on Pesticide Registration Information (Order No. 10 of the Ministry of Agriculture of the People's Republic of China [2007])

3 Terms and definitions

The following terms and definitions apply to this document.

3.1 acute oral toxicity The health-damaging effects that occur in animals in the short term after the test substance is orally administered to experimental animals once or multiple times within 24 hours.

3.2 dose The amount of the test substance administered, which is expressed as the mass of the test substance received per unit body weight of the experimental animal (mg/kg body weight).

3.3 median lethal dose LD

50 The statistical dose of a toxicant that causes half of the total number of animals to die after the test substance is given to the experimental animals once or multiple times within 24 hours. It is expressed as the mass of the test substance received by the experimental animals per unit body weight (mg/kg body weight).

3.4 dose-response relationship The relationship between the dose and the incidence of a specific effect.

4 Purpose of the test

Acute oral toxicity test is the first step to evaluate the toxicity of the test substance. Through short-term administration of toxicant by oral, the toxicity characteristics and dose-response relationship of the test substance are preliminarily understood, which provides a basis for acute toxicity classification, label management and other toxicology test dose selection.

5 Experimental overview

The up-and-down procedure (UDP) is a step-by-step administration procedure. Animals of the same sex are tested, and one animal is administered at a time. The first animal is administered a dose that is preferably lower than the estimated LD

50.The increase or decrease in the subsequent dose of administration depends on the administration result (survival or death) of the previous animal. When the preliminary estimate of the LD50 of the test substance and the slope of the dose-response curve are not available, the computer simulation result suggests that the starting dose can be 175 mg/kg body weight, and the dose interval is calculated using the antilogarithm of 0.5 (corresponding to a default dose progression factor of 3.2). The point estimate value and 95% confidence interval of LD50 are calculated by the maximum likelihood method. NOTE. The dose progression factor is determined by the antilogarithm of the reciprocal of the slope of the dose-response curve (

3.2 is the progression factor for a slope of 2). The number of animals used in the formal test is about 6~

9.The number of animals used in the limit test is no more than

5.This method is only applicable to test substances that cause death within 1~2 days after administration, and is not applicable to test substances that are expected to cause death to happen more than 5 days (including 5 days) after administration.

8 Test report

The test report shall at least include the following contents.

a) Test name, test unit name and contact information, and report number;

b) Test entrusting unit and contact information, sample acceptance date and sample sealing status;

c) The start and end dates of the test, the person in charge of the test project, the technical person in charge of the test unit, and the date of issuance;

d) Test summary;

e) Name of the test substance, Chemical Abstracts Service Number (CAS Number) of the active ingredient (if known), code (if any), purity (or content), dosage form, production date (batch number), physical and chemical properties, solvents used for preparation and method;

f) The species, strain, grade, number, weight, sex, source (supplier name, laboratory animal quality certificate number, laboratory animal production license number), quarantine and adaptation of the experimental animals, the feeding environment of the experimental animals, including temperature, relative humidity, feed, single cage or group feeding, and the license number of the experimental animal facility;

g) Dose and group. including the principle or basis for selecting the dose, the method of animal grouping, sex and number of animals;

h) Test conditions and methods. including main instruments and equipment, routes of administration, administration scheme, test period, observation indicators and method for calculating LD50, etc.;

i) Test results. summarize item by item in the form of text description and table, including clinical manifestations of poisoning, onset, duration and recovery time of poisoning manifestations, time of death after administration, weight changes, correlation with dose, and gross anatomical and histopathological changes, etc., and indicate the statistical processing method of the results;

j) Test conclusion. give clear conclusions, such as LD50, 95% confidence interval and toxicity classification, and discuss relevant issues when necessary;

k) Description of the original record preservation status. termination regulations or terminate the test at a higher dose, so that the LD50 of the test substance is reported to exceed the upper limit and the hazard classification is made;

b) The dose that causes animal death is higher than the dose that causes animal survival, and the LD50 is somewhere in between. This test will not give an accurate LD50 value (if the sigma value is provided, the maximum likelihood ratio LD50 estimate can also be calculated);

c) If the death and survival of the administered animals only occur at the same dose, all the animals die at a dose higher than this dose, and all the animals survive at a dose lower than this dose, then the LD50 is equivalent to this dose. B.1.4 Except for the above cases, the acute oral toxicity test application software package (AOT425StatPgm) can be used to perform the maximum likelihood function calculation. SAS (i.e. PROC NLIN), BMDP (i.e. program AR) or other computer program packages can also be used to complete the maximum likelihood function calculation. In the BASIC program, sigma needs to be programmed as a parameter, and the output result is the estimated value of the logarithm (LD50) and its standard error. B.2 Confidence Interval (CI) calculation B.2.1 Only after the LD50 estimate of the formal test is obtained by using the AOT425StatPgm software package can the confidence interval be calculated and meaningful information be provided for the reliability and effectiveness of the formal test. A wide range of the LD50 confidence interval indicates that there is a lot of uncertainty in the reliability and effectiveness of the estimated LD50; when the confidence interval is narrow, the uncertainty of the LD50 is negligible, and the reliability and effectiveness are relatively high. When the formal test is repeated, the LD50 estimate obtained is closer to the original estimate, and both are closer to the true LD50 value. B.2.2 Two methods for estimating the interval estimate of the true LD50.