1.1 本试验方法确定了暴露在模拟沙质潮汐带环境的实验室条件下的塑料材料的生物降解水平。 1.2 潮汐带，即受潮汐和波浪运动影响的海岸部分，是海洋和陆地之间的边界，通常是一个沙区，由于波浪的拍打而不断保持潮湿。岩石海岸线也存在。 1.3 塑料海洋废弃物经常被冲到这个栖息地，为了恢复原始景观，必须将其清除。 1.4 了解塑料在模拟该栖息地的条件下的生物降解行为很有意义，因为这些信息有助于预测垃圾生物降解所需的时间。 1.5 生物降解通过测量CO来确定 2. 当塑料材料暴露在反应器中用盐水保持湿润的沉积物中时，会发生变化，以模拟潮汐带。 1.6 本标准不考虑海洋淡水栖息地（例如，在微咸水和河口中发现的栖息地）。 1.7 报告应明确说明净CO的百分比 2. 测试完成时测试和参考样品的生成。此外，在实验室报告中，结果不得超出试验的实际持续时间。 注1: 没有已知的ISO等效于本标准。 1.8 单位- 以国际单位制表示的数值应视为标准值。本标准不包括其他计量单位。 1.9 本标准并非旨在解决与其使用相关的所有安全问题（如有）。 本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.10 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 5.1 塑料有时被河流携带，或被船只意外排放入海；这种塑料可以到达海洋环境的不同部分。潮汐和波浪也经常将塑料海洋废弃物输送到沙质潮汐带。 5.2 该测试方法模拟了潮汐区的环境条件。到达沙质潮汐带的塑料碎片可以在那里沉降，部分或全部被沙土掩埋，并被波浪或潮汐润湿。评估塑料材料在这些条件下的生物降解行为，以预测这种废物在环境中的去除时间，是一件很有意义的事情。 5.3 本试验方法用于确定实验室中暴露在海水湿润的砂质沉积物中的塑料的生物降解程度。沉积物和海水均来自潮汐带的沙滩。如果沉积物中的自然微生物种群能够生物降解塑料，则会进化出CO 2. 由于有氧微生物呼吸。 任何给定时间的生物降解水平是在塑料中存在的有机碳全部转化为二氧化碳的情况下，释放的净二氧化碳的累积量与产生的理论量之间的比率。 5.4 本试验方法不测量转化为生物质的有机碳量，而仅测量导致矿化的生物降解（即CO的形成） 2. ).

1.1 This test method determines the biodegradation level of plastic materials exposed to laboratory conditions that simulate the environment found in the sandy tidal zone. 1.2 The tidal zone, that is, the part of the coast affected by the tides and movement of the waves, is the borderline between sea and land, frequently a sandy area that is kept constantly damp by the lapping of the waves. Stony and rocky shorelines also exist. 1.3 Plastic marine debris is frequently washed up in this habitat where it must be removed in order to restore the original landscape. 1.4 It is of interest to know the biodegradation behavior of plastics when exposed to conditions simulating this habitat, because this information can help in predicting the time needed for the biodegradation of the litter. 1.5 Biodegradation is determined by measuring the CO 2 evolved by the plastic material when exposed to a sediment kept wet with salt-water in a reactor, to simulate the tidal zone. 1.6 Marine fresh-water habitats (for example, those found in brackish waters and estuaries) are not considered by this standard. 1.7 Reports shall clearly state the percentage of net CO 2 generation for both the test and reference samples at the completion of the test. Furthermore, in the laboratory reports, the results shall not be extrapolated beyond the actual duration of the test. Note 1: There is no known ISO equivalent to this standard. 1.8 Units— The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.9 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.10 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 5.1 Plastic is sometimes carried by rivers or accidentally discharged by ships into the sea; this plastic can then reach different parts of the marine environment. Tides and waves also frequently deliver plastic marine debris into the sandy tidal zones. 5.2 This test method simulates the environmental conditions found in the tidal zone. Plastic debris that reaches the sandy tidal zone can settle there and become partially or totally buried by sand and kept wet by waves or tides. It is of interest to assess the biodegradation behavior of plastic materials under these conditions to predict the removal time of this waste in the environment. 5.3 This test method is applied to determine the extent of biodegradation of a plastic exposed in the laboratory to a sandy sediment kept wet with seawater. Both sediment and seawater are collected from a sandy beach in the tidal zone. If the natural microbial population present in the sediment is able to biodegrade the plastic, there will be an evolution of CO 2 as a consequence of the aerobic microbial respiration. The level of biodegradation at any given time is the ratio between the cumulative amount of the evolved net carbon dioxide and the theoretical amount produced in the case of total conversion of the organic carbon present in the plastic into carbon dioxide. 5.4 This test method does not measure the amount of organic carbon that is converted into biomass, but only the biodegradation that leads to mineralization (that is, the formation of CO 2 ).