ASTM_D_7473_-_D_7473M_-_21.pdf

Designation:D7473/D7473M21Standard Test Method forWeight Attrition of Non-floating Plastic Materials by OpenSystem Aquarium Incubations1This standard is issued under the fixed designation D7473/D7473M;the number immediately following the designation indicates theyear of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of lastreapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This test method is used to determine the weight loss asa function of time of non-floating plastic materials(includingformulation additives),when incubated under changing,open,marine aquarium conditions,which is representative of aquaticaerobic environments near the coasts and near the bottom of abody of water in the absence of sunlight,particularly UV andvisible portions of the spectrum.The goal of this test is toobtain data that can be used to assess the potential for physicaldegradation of the test material.Such potential for physicaldegradation will be affected by real life environmental condi-tions.1.2 In particular this test method does not take into consid-eration the possible effects of solar irradiation.1.3 The aquarium-incubated plastic materials are examinedfor visual degradation and dry weight loss over time.This testdoes not provide information on ultimate biodegradation(thatis,it is not a replacement for Test Method D6691),but it is anASTM method for weight attrition.The standard addressesonly weight loss as a function of time of the plastics materialsin a marine environment and shall not be used for demonstrat-ing ultimate biodegradation.1.4 This test method does not provide information regardingthe potential formation of microplastics due to the physicaldegradation of the samples.1.5 Plastic pieces of known size and thickness are used atlevels so as not to exceed the availability of micronutrientsessential for and therefore limit the microbial processes.1.6 The aquarium incubation test method allows for repre-sentative indigenous microorganisms present in seawater andmarine sediment to be enriched for and carry out the biodeg-radation.It is recommended that the test be carried out in thegeographical vicinity(latitudinal area)where the test materialsare likely to be used.These Aquarium studies are conducted inindoor environments,hence any sunlight-induced effects ondegradation,or biodegradation,or both,are not taken intoaccount.1.7 This test by itself shall not be used as the basis forclaims,such as“Biodegradable in Marine Environments”sinceit is only a weight loss test method.This test method is solelya means for measuring a characteristic(physical degradation)under standard conditions.It does not assess the generalenvironmental impact of plastic products.1.8 UnitsThe values stated in either SI units or inch-pound units are to be regarded separately as standard.Thevalues stated in each system are not necessarily exact equiva-lents;therefore,each system shall be used independently of theother.Combining values from the two systems has the potentialto result in non-conformance with the standard.1.9 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.NOTE1There is no known ISO equivalent to this standard.1.10 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsD6691 Test Method for Determining Aerobic Biodegrada-tion of Plastic Materials in the Marine Environment by aDefined Microbial Consortium or Natural Sea WaterInoculum1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.96 on EnvironmentallyDegradable Plastics and Biobased Products.Current edition approved March 1,2021.Published March 2021.Originallyapproved in 2012.Last previous edition approved in 2012 as D7473 12.DOI:10.1520/D7473_D7473M21.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principle