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GB/T 21788-2025: Chemicals - Test method of bacterial reverse mutation
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Std ID	Version	USD	Buy	Deliver [PDF] in	Title (Description)
GB/T 21788-2025	English	239	Add to Cart	3 days [Need to translate]	Chemicals - Test method of bacterial reverse mutation
GB/T 21788-2008	English	229	Add to Cart	3 days [Need to translate]	Chemicals -- Test method of combined chronic toxicity/carcinogenicity study

GB/T 21788-2025: Chemicals - Test method of bacterial reverse mutation

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ICS 13.300 CCSA80 National Standards of the People's Republic of China Replaces GB/T 21788-2008 Combined Test Methods for Chronic Toxicity and Carcinogenicity of Chemicals Published on 2025-08-29 Implemented on December 1, 2025 State Administration for Market Regulation The State Administration for Standardization issued a statement.

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part 1.Structure and Drafting Rules of Standardization Documents". Drafting. This document supersedes GB/T 21788-2008 "Combined Test Methods for Chronic Toxicity and Carcinogenicity of Chemicals", and is consistent with GB/T 21788- Compared to.2008, aside from structural adjustments and editorial changes, the main technical changes are as follows. ---The "Animal Selection" section has been revised, including animal selection, animal preparation, animal quantity, and sex (see 5.3.1,.2008 version). 3.3.1); ---The husbandry conditions have been modified (see 5.3.2, version 3.3.2 from.2008); ---The "Animal Quantity and Sex" section has been modified (see 5.3.4, version 3.3.4 from.2008). ---The "Dose Level" section has been revised, adding "Key Considerations for Dosage Selection," "Solvent Selection," and "Test Substance Concentration" (see...). 5.4 (3.4 in the.2008 edition); ---The "Route of Exposure" section has been revised (see 5.6, 3.6 in the.2008 version); ---The "Exposure Cycle" section has been modified (see 5.7, 3.7 in the.2008 version); ---The "Observation" section has been revised, and two new chapters, "Chronic Toxicity Testing" and "Carcinogenicity Testing," have been added (see sections 5.8 and 5.9,.2008 edition). 3.8); ---The content regarding clinical observation, weight, and food intake has been revised, and water intake has been added (see 5.8.1 and 5.8.2, 3.8.1 in the.2008 edition). 3.8.2 and 3.8.3); ---The content of hematological and clinical biochemistry examinations has been revised, with detailed regulations on testing time, number of animals, and testing indicators (see...). Versions 5.8.3 and 5.8.4, and versions 3.9 and 3.11 (2008 editions) ---The content of "Gross Autopsy" and "Histopathological Examination" has been revised; the organs for histopathological examination have been updated, specifying that paired organs must be examined in pairs. Both sides should be saved for inspection (see 5.8.6 and 5.8.7, 3.12.1 and 3.12.2 in the.2008 edition); ---The "Data and Reporting" section has been revised, providing detailed specifications for test substances, solvents, laboratory animals, experimental conditions, results, and discussions (see section [number]). Chapter 6 (Chapter 4 of the.2008 edition). Please note that some content in this document may involve patents. The issuing organization of this document assumes no responsibility for identifying patents. This document was proposed and is under the jurisdiction of the National Technical Committee on Standardization of Hazardous Chemicals Management (SAC/TC251). This document was drafted by. the Institute of Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention; and the Shandong Provincial Institute of Occupational Health and Occupational Disease Prevention and Control. Research Institute, China Standards (Ningde) Technology Co., Ltd. The main drafters of this document are. Jia Qiang, Chen Xiao, Bo Cunxiang, Li Bin, Xiao Jingwei, Zhang Yi, Li Ming, Li Chao, and Lin Ying. The release history of this document and the document it replaces is as follows. ---First published in.2008 as GB/T 21788-2008; ---This is the first revision.

introduction

The combined chronic toxicity and carcinogenicity test involves repeated exposure of laboratory animals to the test substance over a period of time during their normal lifespan to detect the potential for carcinogenicity in the body. Information on potential health hazards, including toxicity of the test substance, carcinogenicity, target organs, accumulation, and doses at which no adverse effects were observed. Levels (NOAEL), etc. For non-genotoxic carcinogens, these can be used to establish safety standards for human exposure. This testing guide is used for testing a wide range of chemicals, including pesticides and industrial chemicals, primarily applicable to rodents. Non-rodents... Animals should be appropriately modified, or refer to OECD DTG 409 and OECD guidance document No. 116.Test substances are typically administered orally or dermally. For drug administration via inhalation, the choice of route of administration depends on the physicochemical properties of the test substance and the main routes of human exposure. This document focuses on the most... Commonly used routes of oral exposure. For inhalation exposure, refer to OEC DTG 412, OEC DTG 413, and guidelines for acute inhalation-related exposure. OECD guidance document; for exposure via skin, refer to OECD TTG 410. The experimental design includes two parallel parts. a chronic toxicity study and a carcinogenicity study. The objectives of these studies include. a) Identification based on increased tumor incidence, elevated proportion of malignant tumors, and shortened time to tumor onset, compared with the control group. Carcinogenicity of the test substance; b) Determine the time of tumor appearance; c) Identify the chronic toxicity of the test substance; d) Identify target organs for chronic toxicity and carcinogenicity; e) Determine the dose-response relationship; f) Determine the NOAEL or starting point to establish a baseline dose (BMD); g) Extrapolating carcinogenic effects to low-dose exposure populations; h) Predict chronic toxicity at human exposure levels; i) To provide data for testing hypotheses about the mechanism of action of the test substance. A combined chronic toxicity and carcinogenicity study was conducted, rather than separate chronic toxicity and carcinogenicity studies. The combined study is superior to two separate studies. This method is more efficient in terms of both time and cost, while ensuring the quality of experimental data. Dosage selection should be considered when conducting the experiment. The principle is to conduct separate experiments in special circumstances. Combined Test Methods for Chronic Toxicity and Carcinogenicity of Chemicals 1.Scope This document specifies the basic principles, test methods, data, and reporting for combined testing of chronic toxicity and carcinogenicity of chemicals. This document applies to the testing of the chronic toxicity and carcinogenicity of chemicals.

2 Normative references

The contents of the following documents, through normative references within the text, constitute essential provisions of this document. Dated citations are not included. For references to documents, only the version corresponding to that date applies to this document; for undated references, the latest version (including all amendments) applies. This document. GB 14925 Laboratory Animal Environment and Facilities 3.Terms and Definitions The following terms and definitions apply to this document. 3.1 Chronic toxicity The health damage effects caused by repeated exposure of animals to the test substance for most of their normal life cycle. 3.2 target organ The organ in which the test substance causes a significant toxic effect on the body. 3.3 Under specified test conditions, using existing technical means and detection indicators, the test substance for which no harmful effects related to poisoning were observed was the least likely to be found. High doses or concentrations. 4.Basic Principles of the Experiment The laboratory animals are exposed to the test substance in a certain way for a long period of time throughout most of their life cycle. The symptoms of poisoning are observed, and biochemical indicators are analyzed. Examinations such as biomarkers, hematological indicators, and histopathological examinations were conducted to evaluate the chronic toxicity of the test substance; simultaneously, the number and type of tumors in the animals were observed. The location and time of occurrence are used to evaluate the potential carcinogenicity of the test substance. 5.Test Methods 5.1 Oral exposure test substance The relevant information includes. a) Solids or liquids, etc.; b) Chemical identification characteristics; c) Purity (impurities and content); d) Solubility; e) Stability (including stability of the preparation after mixing with feed and drinking water); f) The relationship between hydrolysis and pH; g) The ability to form complexes; h) Melting point/boiling point. 5.2 Inhalation exposure test substance The relevant information includes. a) Gases, volatile substances, or aerosols/particulate matter; b) Chemical identification characteristics; c) Purity and impurities; d) Liquid test substance. saturated vapor pressure, boiling point; e) Aerosol/particulate matter test samples. particle size, shape, and dispersion; f) Flash point of the test substance; g) Explosiveness of the test substance. 5.3 Laboratory animals and their housing 5.3.1 Animal Selection Use young, healthy adult animals. Species selection should be appropriate, with rodents (rats) being the first choice, but mice can also be used. When existing numbers... When non-rodent animals are shown to be more relevant in predicting human health effects, they should be used. Combined chronic toxicity and carcinogenicity testing. Animals of the same strain and origin as those used in the initial short-term trials should be given priority. Animal survival rates should be considered when selecting animals for long-term trials. 5.3.2 Rearing Environment Laboratory animals should be housed individually or in groups of the same sex. Animal husbandry and management should comply with the requirements of GB 14925.Feed... It should meet the required nutritional needs and control pollutants such as pesticide residues, persistent organic pollutants, phytoestrogens, heavy metals, and mycotoxins. Content. Feed nutrient composition and contaminant levels should be analyzed regularly, at least at the start of the study and whenever changes occur in the feed batches used. The analysis is performed, and the analytical information is presented in the final report, which also provides information on animal drinking water analysis. When the test substance is mixed into the animal's diet, the animal feed... The choice of feed should ensure that it is properly mixed with the test substance and meets the nutritional requirements of the animal. 5.3.3 Animal Preparation Experimental animals that have not been previously tested and have been acclimatized to experimental conditions for at least 7 days should be used. Rats should begin staining as soon as possible after weaning and acclimatization. Toxicity should ideally be introduced before 8 weeks of age. Laboratory animals should be labeled with their strain, origin, sex, weight, and age. At the start of the experiment, the animals' weight difference should be considered. The abnormal response should not exceed ±20% of the average body weight of all animals of the same sex. Laboratory animals should be randomly divided into a control group and a treatment group, with each group within the same sex... The average weight of the animals should not vary significantly, and each animal should be uniquely and permanently marked. 5.3.4 Animal Number and Sex Animals of both male and female should be used. The number of experimental animals should meet biological and statistical requirements. For the carcinogenicity test, rats should be used. For example, each dose group and control group should contain at least 50 experimental animals per sex. Depending on the experimental objectives, different dosage groups can be set up. Number of experimental animals. For example, the number of animals in the low-dose group exceeds 50 to evaluate the carcinogenic potential of the low-dose group. Chronic toxicity testing section, for each dose... Each dose group and control group should contain at least 10 rats of each sex. When mice are used in the testing, the number of dose groups in the chronic toxicity test can be adjusted accordingly. The number of animals was increased to meet the requirements for hematological examination. ...