Document J3wb6wpLQ4Yad01nbawXyxY9O

AR226-2735 TRADE SRfttFT Study Title EVALUATION OF THE BIODEGRADABILITY OF C-8 USING THE MODIFIED STURM TEST (OECD 301 B) Author John T. Gannon Jr., Ph.D. Study Completed nn 3/11/97 Performing Laboratory E. I. du Pont de Nemours and Company Central Research & Development Environmental Biotechnology Glasgow Business Community 301, P.O. Box 6101 Newark, DE 19714-6101 AEM Laboratory Report No. 24-97 Page 1 of 8 Company Sanitized. Does not contain TSCA CB1 AEMR # 24-97 GENERAL INFORMATION Material Tested: C-8 Synonyms/Codes: None Submitter's Notebook No.: N/A Sponsor: Roger Zipfel FLPR Washington Works Experimental Start & Completion: 1/21/97 to 3/11/97 -2- .Company Sanitized. Does not contain TSCA CBI AEMR # 24-97 EVALUATION OF THE BIODEGRADABILITY OF C-8 USING THE MODIFIED STURM TEST (OECD 301 B) SUMMARY The test chemical - C-8 - was tested for biodegradability using the Modified Sturm Test. Within the 28-day test period, C-8 reached a peak of 13 % at Day 28. Since the "PASS" criteria for the Modified Sturm Test is 60 % biodegradability in a 10 day window within the 28 day test period, it may be concluded that C-8 did not demonstrate "Ready Biodegradability". Please note that failure to pass a "Ready Biodegradability Test" does not imply that the test material will persist in the environment for an extended period of time. Furthermore, evaluation of the individual components of the formulation would yield more specific information on the biodegradability potential of C-8. ^- Study Conducted By: ^^o^^C. {tcoX^^ 2 /y//7/ George A. Fisher (date) Senior Microbiology Technician Report Prepared and Approved for Issue By: ^/^- n i ^\ Q/ (/ohn T. Ga{n'noyrT^jrw., ^Phv.D._~ / / -Y//7 7 / (date) Senior Research Microbiologist -3- Sompany Sanitized. Does not contain TSCA CBI AEMR # 24-97 Introduction/Purpose The Modified Sturm Test was performed to determine the biodegradability of the test material, C-8. The Modified Sturm Test can be used for either water-soluble or water-insoluble and non-volatile chemicals. In this test, biodegradability is measured as COz evolution- When bacteria biodegrade an organic chemical in an aerobic system, the end product of the metabolism is carbon dioxide. Therefore, carbon dioxide evolution is indicative of a chemical being biodegraded. If COz evolution is greater than 60 %, then Ready Biodegradability has been demonstrated and no further testing is necessary. This "PASS" value must be reached in a 10-day window within the 28 day period of the test. The 10 day window begins when the degree of biodegradadon has reached 10 % ThCO^, and must end before day 28 of the Modified Sturm Test. Materials/Methods The Modified Sturm Test determination was conducted in accordance 1 with AEM SOP MI056-P: Modified Sturm Test. See Table for materials tested. Activated sludge collected from the City of Wilmington, DE POTW was used as the inoculum. Results/Discussion Day that In the Modified Sturm Test, C-8 reached a peak of 13 % at 28 (Table 2 and Figure 1). Therefore, it may be concluded "Ready Biodegradability" was not demonstrated. Please note that failure to pass a "Ready Biodegradability Test" does not imply that the- test material will persist in the environment for an extended period of time. Furthermore, evaluation of the individual components of the formulation would yield more specific information on the biodegradability potential of C-8. The reference chemical, so'dium benzoate, exceeded 60 % biodegradability within 14 days, therefore the biodegradability was considered valid (Table 2 and Figure 1). test The Theoretical CO; Produced was 0.24 mg CO; per mg of 30 % C-8. -4- Company Sanitized. Does not contain TSCA CB8 AEMR # 24-97 The toxicity test (which includes both the test chemical and the reference chemical in the same flask) yielded less than 25 % biodegradadon within 14 days, therefore C-8 was considered as inhibitory to microorganisms in the inoculum. Path Forward Discussion If it can be assumed that the 30 % C-8 solution was essentially pure with only trace levels of impurities, then there may be a possibility that the terminal carbon (COO') may have been biodegraded by the microorganisms. As a path forward, we will repeat the experiment to determine if we have reproducible results. The Modified Sturm Test is used to determine biodegradability of organic chemicals by measuring the amount of CO; evolved without using ^C labelled carbon. Therefore, the analysis is non-specific and it is not possible to conclusively determine which carbon was attacked by the microorganisms. If reproducible results are observed upon repeating the Modified Sturm Test, then it is recommended that a follow-up biodegradability test should be conducted with '"C labelled carbon on the terminal C (COO-) of C-8. This will allow for the conclusive determination as to whether Ae terminal carbon of C-8 is biodegraded. -5- Company Sanitized. Does not contain TSCA CBI AEMR # 24-97 TABLE 1 Description of Test and Control Substances Test Substance Description C-8 Sodium Benzoate 'Company Sanitized. Does not contain TSCA CBI 180 V3SA u|8uoo |ou saoo -pazfflues AuedtUGQ -Z.- z-e-^z # "aiMav Figure 1: Modified Sturm Test