塑料.中温实验室试验条件下固体塑料材料比需氧生物降解速率和消失时间（DT50）的测定

[中文适用范围]： 本文件规定了在中温条件下测定固体非水溶性塑料材料特定需氧生物降解率的方法。注：特定需氧生物降解率（严格地说，是特定矿化率，指评估有机碳转化为二氧化碳但忽略生物质形成）表示为单位时间、单位面积中碳矿化成二氧化碳的量。本文件中描述的方法不提供有关测试样品最终需氧生物降解性的信息。例如，ISO 23517 和 ISO 22403 规定了塑料材料在中温条件下的生物降解性标准。仅当使用合适的标准规范（例如 ISO 23517 和 ISO 22403）证明塑料材料本质上可生物降解时，才应使用本文件中描述的方法来确定 DT50。此外，对于最终生物降解尚未得到证明的塑料材料，所确定的生物降解率不应被视为整个材料的特定特性。本文件仅将 CO2 的释放视为测试样品矿化的直接测量。本文件中描述的方法也可应用于用作参考的固体材料。本文件不适用于可生物降解塑料材料的“海洋、土壤和淡水可生物降解”声明。为此，请参阅相关产品标准（如有）。注：尽管结果可以表明，所测试的塑料材料和聚合物将在规定的测试条件下以特定的有氧生物降解速率或 DT50 进行生物降解，但任何实验室暴露的结果都不直接适用于实际使用或泄漏地点的环境区域，包括土壤、海洋环境和淡水区域。 [外文原描述]： This document specifies a method to determine the specific aerobic biodegradation rate of solid, non-water soluble plastic materials under mesophilic conditions. NOTE The specific aerobic biodegradation rate (which, strictly speaking, is a specific mineralization rate, implying the assessment of the conversion of organic carbon into CO 2 but neglecting biomass formation) is expressed as amount of carbon mineralized into CO 2 , per unit time, per unit area. The method described in this document does not provide information on the ultimate aerobic biodegradability of the tested samples. Biodegradability criteria for plastic materials under mesophilic conditions are provided for example by ISO 23517, and ISO 22403. The method described in this document shall be used to determine the DT50 only when the plastic material is proven to be intrinsically biodegradable using suitable standard specifications such as ISO 23517 and ISO 22403. Furthermore, the biodegradation rate determined on plastic materials whose ultimate biodegradation has not been proven, shall not be considered as a specific characteristic of the whole material. This document only considers the evolution of CO 2 as direct measurement of mineralization of the tested sample. The method described in this document may be applied also to solid materials used as a reference. This document is not applicable for “marine, soil and freshwater biodegradable” claims of biodegradable plastic materials. For such purposes, see relevant product standards if available. NOTE Although results can indicate that the tested plastic materials and polymers will biodegrade under the specified test conditions at a certain specific aerobic biodegradation rate or DT50, the results of any laboratory exposure are not directly applicable to environmental compartments including soil, marine environments and limnic areas at the actual site of use or leakage.