Meaning and use
4.1 The relatively rapid deterioration of chemical, physical and mechanical properties of materials made from photodegradable plastics when exposed to light, heat and water after achieving their intended purpose. This practice is designed to cause changes in properties related to the conditions the material may encounter when discarded as garbage, including the effects of sunlight, moisture, and heat. The exposures used in this practice are not intended to simulate deterioration caused by local weather phenomena such as atmospheric pollution, biological attacks, and salt water exposure.

4.2 Precautions – When operating conditions vary within the acceptable limits of this practice, results can be expected to change. Therefore, reference to the use of this practice must not be made unless accompanied by a report prepared in accordance with section 9 describing the specific operating conditions used. For more information about the precautions that apply to using results obtained under this practice, see Practice G151.

Note 2: For additional information on sources of variability and strategies to address variability in the design, execution, and data analysis of laboratory accelerated exposure trials, see Guideline G141.

ASTM D5208-2022 Standard Practice for Fluorescent Ultraviolet Rays

4.3 Simultaneous exposure to similar materials with known properties (controls) with the sample provides criteria for comparison purposes. The use of controls to rank the stability of test materials greatly improves consistency across different laboratories. It is recommended that at least three repetitions of the material for each evaluation be performed in order to statistically evaluate the results.

4.4 Test results will depend on the degree of care taken to operate the equipment in accordance with practice G154. Important factors include regulation of the line voltage, the temperature of the room in which the equipment is operating, temperature control, and the condition and age of the lamp (if exposed in equipment without irradiance control).

Radius
1.1 This procedure covers specific procedures applicable to fluorescent ultraviolet (UV) irradiation of photodegradable plastics in accordance with procedures G151 and G154. The practice also includes the preparation of test samples and the evaluation of test results.

1.2 Practice D4329 covers fluorescent UV exposure to plastics used for outdoor applications.

ASTM D5208-2022 Standard Practice for Fluorescent Ultraviolet Rays

1.3 Values expressed in SI units shall be treated as standard values. The values given in parentheses are for reference only.

1.4 This standard is not intended to address all safety concerns, if any, associated with its use. It is the responsibility of users of this standard to establish appropriate safety, health and environmental practices and to determine the applicability of regulatory restrictions prior to use.

Note 1: There is no known ISO equivalent to this standard.

1.5 This international standard is based on internationally recognized standardization principles established in the Decision on Principles for the Development of International Standards, Guidelines and Recommendations issued by the WTO Committee on Technical Barriers to Trade.