ASTM_E_1720_-_01_2008.pdf

Designation:E 1720 01(Reapproved 2008)Standard Test Method forDetermining Ready,Ultimate,Biodegradability of OrganicChemicals in a Sealed Vessel CO2Production Test1This standard is issued under the fixed designation E 1720;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers procedures for determining theready,ultimate,aerobic biodegradability of organic chemicalsby monitoring CO2production in sealed vessels containing thetest compound and a dilute sewage inoculum.Because of thestringency of the test conditions,it can be assumed that achemical that is 60%or better biodegraded in this test methodwill biodegrade in most aerobic environmental compartments.1.2 This test method is derived from the sealed vesselprocedures of Birch(1),2Struijs(2),Boatman(3),and Peterson(4),which were developed as simpler,more economicalalternatives to the CO2production techniques reported byGledhill(5)and Sturm(6),the Sturm report being the basis ofthe Modified Sturm Test of the Organization for EconomicCooperation and Development(OECD)(7).1.3 The procedures are applicable to pure materials,includ-ing sparingly solubles,which can be dissolved or dispersedhomogeneously in aqueous stock solutions of at least 25 ppmof carbon,or which can be introduced reproducibly to testbottles as pure test material in 1 to 2-mg portions.The testchemical should be nontoxic to sewage microorganisms at 10ppm of carbon.The test may be applied to volatile materialswith Henrys Law Constants of up to approximately 102atm/m3/mole.The testing of mixtures,extracts,or fully formu-lated products can lead to serious problems in data interpreta-tion.1.4 The procedures involve incubation of the test chemicalwith a dilute inoculum of microbes from domestic wastewatersecondary sewage treatment effluent in small,sealed vesselsfor up to 28 days.Biodegradability is determined by monitor-ing CO2production as dissolved inorganic carbon(DIC)in theliquid phase,and as gaseous CO2in the head space.Alterna-tively,analysis can be performed on just the liquid phase afterthe addition of alkali,or on just the headspace followingacidification.The determinations are made using commercialcarbon analyzers based on the IR detection of CO2.Thedetermination of CO2production provides unequivocal proofof biodegradation,barring the unlikely event of abiotic pro-duction of CO2from the test material.1.5 For water-soluble materials that do not adsorb to glassor biological solids,biodegradation may be confirmed furtherby monitoring the disappearance of dissolved organic carbon(DOC)in the liquid phase.1.6 The simplicity of the sealed vessel method permitsample replicate sampling for rate determination or statisticalevaluation,or both.1.7 For a chemical that fails the test as written,the strin-gency of the test may be reduced by substituting an acclimatedinoculum in order to provide a measure of inherent biodegrad-ability.1.8 Materials that are toxic to the microbial inoculum at 10ppm of carbon may not be amenable to testing by this testmethod,or they may require special method modification suchas reducing the test concentration if instrumental sensitivitypermits.For some cationics,complexing the test material witha nondegradable anionic may reduce toxicity.1.9 The values stated in SI units are to be regarded as thestandard.1.10 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 and health practices and determine the applica-bility of regulatory limitations prior to use.For specificprecautionary statements,see Section 6.2.Summary of Test Method2.1 Biodegradation testing of organic chemicals is per-formed by monitoring CO2production in small sealed vesselsinoculated with microbes from secondary sewage treatmenteffluent obtained from a local domestic sewage treatment plant.The types of test chemicals for which the test is recommended,and those for which special considerations may be required,aresummarized in 1.3.1This test method is under the jurisdiction of ASTM Committee E47 onBiological Effects and Environmental Fate and is the direct responsibility ofSubcommittee E47.04 on Environmental Fate and Transport of Biologicals andChemicals.Current edition approved Feb.1,2008.Published April 2008.Originallyapproved in 1995.Last previous edition approved in 2001 as E 1720-015.2The boldface numbers in parentheses refer to the list of references at the end ofthis standard.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.2.2 Alternatively,smaller vessels(40-mL VOA vials or20-mL serum vials)containing 25 or 13 mL of medium,respectively may be