GB/T 2421-2020 "Environmental Testing—General and Guidance": This standard came into effect on December 1, 2020, primarily applicable to electrical and electronic products, and can also be extended to other fields. It provides a framework and essential stages for tailoring environmental testing processes, referencing relevant international standard systems, and clarifies the core logic of climatic, mechanical, and combined environmental tests. By establishing unified and repeatable test methods and standard atmospheric conditions, it helps evaluate the operational capability of products in transportation, storage, and usage environments, providing fundamental guidance for the formulation of product specifications and the implementation of tests.