On November 1, 2026, the recommended national standard GB/T 19811-2026, "Plastics-Determination of the degree of disintegration of plastic materials under defined pilot-scale composting conditions," officially came into effect. It replaces the previous version, GB/T 19811-2005, and is technically equivalent to ISO 16929:2021. The standard is administered by the National Technical Committee on Bio-based Materials and Degradable Products (TC380).
As a key component of the comprehensive evaluation system for compostable plastics, this standard specifies methods for testing the degree of disintegration of plastic materials under pilot-scale aerobic composting conditions. By simulating scenarios closely resembling actual industrial composting, it is used to assess the fragmentation of degradable plastics during the composting process and the quality of the resulting compost. It should be noted that this standard is intended solely for measuring disintegration performance; it cannot serve as the sole basis for determining a material's biodegradability. A full assessment of compostability requires additional testing, such as the determination of the biodegradation rate.
Compared to the 2005 version, this revision optimizes several core test conditions: the minimum volume for composting vessels has been reduced from 140 L to 35 L-with a corresponding decrease in the minimum required input of organic waste-thereby lowering the threshold for laboratory testing. The temperature control ranges throughout the composting cycle have been refined to improve the repeatability and comparability of data across different testing facilities. Furthermore, the standard removes obsolete terminology, adds practical guidance for test procedures, and streamlines the sample preparation requirements for ecotoxicity (biotoxicity) testing. These updates ensure a more rigorous and standardized testing process, aligning it with international evaluation protocols.
