ASTM WK71923

    Revision of D7473 - 12 Standard Test Method for Weight Attrition of Plastic Materials in the Marine Environment by Open System Aquarium Incubations

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    Developed by Subcommittee: D20.96 | Committee D20 | Contact Staff Manager



    WK71923


    Keywords


    Rationale

    D7473 is a standard test method that needs to be revised or reapproved by December 31, 2020 or it will be withdrawn. D7473 is a standard test method to measure the weight loss of plastic materials when exposed to seawater and marine sediments in an aquarium. According to ASTM, a test method is a definitive procedure that produces a test result. On the other hand, a standard specification is an explicit set of requirements to be satisfied by a material, product, system, or service. The current version of D7473 describes a test method and procedure to characterize materials and obtain results. Therefore, in this revised version should also be classified as a test method as it was in the past. However, in several areas in the current version it sets criteria for performing D7473. The current version gives biodegradability requirements to be demonstrated by using other test methods and specifications (e.g. mentioning that only materials that show a minimum 30% mineralization can be tested using D7473). These type of statements will be removed as to make this an independent test method. A standard test method should stand alone and intend to provide a test result. Weight loss, which is being measured in this test method can span from 0 to 100% and any result is informative. A test method is neutral about the results and does not provide any further information beyond them (besides the quality of the results e.g. precision etc.). On the other hand, the evaluation of test results is the specific task of a specification. The undue reference to a specification as a precondition for testing must be deleted for the following reasons: (1) the reference to other test methods and specifications can become obsolete making the test method unserviceable; (2) the reference to other test methods and specifications makes it impossible to test unidentified samples whose biodegradability characteristics are unknown. Thus, unknown samples randomly taken from the market cannot be tested; (3) test methods are neither directly nor indirectly meant to set requirements. The current revised document update the original D7473 and makes the test method usable again and totally consistent with the ASTM definitions.

    Citing ASTM Standards
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    Work Item Status

    Date Initiated:
    02-13-2020

    Technical Contact:
    Francesco Degli Innocenti

    Status:
    Draft Under Development