1.1 本规程涵盖了适用于根据规程进行的光降解塑料荧光紫外线（UV）暴露的具体程序 G151页 和 G154页 . 本规程还包括试样的制备和试验结果的评估。 1.2 实践 D4329 涵盖用于户外长期使用的塑料的荧光紫外线暴露。 1.3 以国际单位制表示的数值应视为标准值。括号中给出的值仅供参考。 1.4 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。 注1: 没有已知的ISO等效于本标准。 1.5 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====== 4.1 由光降解塑料制成的材料在达到预期目的后，暴露于光、热和水时，其化学、物理和机械性能会出现相对快速的劣化。 该实践旨在诱导与材料作为垃圾丢弃时可能经历的条件相关的特性变化，包括阳光、水分和热量的影响。本实践中使用的暴露不是为了模拟局部天气现象引起的恶化，例如大气污染、生物攻击和盐水暴露。 4.2 注意事项- 当操作条件在本规程的可接受范围内变化时，可以预期结果的变化。因此，除非附有根据第节编制的报告，否则不得提及本惯例的使用 9 这描述了使用的特定操作条件。参考实践 G151页 有关适用于使用根据本规程获得的结果的注意事项的详细信息。 注2: 指南中提供了关于可变性来源以及解决实验室加速暴露试验设计、执行和数据分析中可变性的策略的更多信息 G141页 . 4.3 与试样同时暴露具有已知性能的类似材料（对照）为比较提供了标准。使用控件对测试材料的稳定性进行排序，大大提高了不同实验室之间的一致性。 3. , 4. 建议对每种评估的材料至少进行三次重复，以便对结果进行统计评估。 4.4 测试结果将取决于按照惯例操作设备时的谨慎程度 G154页 . 如果在没有辐照度控制的设备中进行曝光，则重要因素包括线路电压的调节、设备运行房间的温度、温度控制以及灯具的条件和寿命。

1.1 This practice covers the specific procedures applicable for fluorescent Ultraviolet (UV) exposure of photodegradable plastics conducted in accordance with Practices G151 and G154 . This practice also covers the preparation of test specimens and the evaluation of test results. 1.2 Practice D4329 covers fluorescent UV exposures of plastics intended for long term use in outdoor applications. 1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only. 1.4 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. Note 1: There is no known ISO equivalent to this standard. 1.5 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 ====== 4.1 Materials made from photodegradable plastics are intended to show relatively rapid deterioration of chemical, physical, and mechanical properties when exposed to light, heat, and water after fulfilling their intended purpose. This practice is intended to induce property changes associated with conditions that might be experienced when the material is discarded as litter, including the effects of sunlight, moisture, and heat. The exposure used in this practice is not intended to simulate the deterioration caused by localized weather phenomena such as atmospheric pollution, biological attack, and salt water exposure. 4.2 Cautions— Variation in results can be expected when operating conditions are varied within the accepted limits of this practice. Therefore, no reference to the use of this practice shall be made unless accompanied by a report prepared in accordance with Section 9 that describes the specific operating conditions used. Refer to Practice G151 for detailed information on the caveats applicable to use of results obtained in accordance with this practice. Note 2: Additional information on sources of variability and on strategies for addressing variability in the design, execution and data analysis of laboratory accelerated exposure tests is found in Guide G141 . 4.3 Exposure of a similar material of known performance (a control) at the same time as the test specimens provides a standard for comparative purposes. Use of a control to rank the stability of test materials greatly improves agreement between different laboratories. 3 , 4 It is recommended that at least three replicates of each material evaluated be exposed to allow for statistical evaluation of results. 4.4 Test results will depend upon the care that is taken to operate the equipment in accordance with Practice G154 . Significant factors include regulation of line voltage, temperature of the room in which the device operates, temperature control, and condition and age of the lamps, if exposure is conducted in a device without irradiance control.