Registration Dossier

Environmental fate & pathways

Biodegradation in water: screening tests

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

Ready Biodegradability_Manometric Respirometry Test_OECD 301F: 24 % degradation within 55 days exposure period (the substance is not readily biodegradable).

Key value for chemical safety assessment

Additional information

The test substance 1,2,3-Propanetriol, glycidyl ethers was investigated for its ready biodegradability in a manometric respirometry test over 55 days according to the OECD Guideline 301 F, EU Method C.4‑D and US EPA Draft OPPTS 835.3110 (Paragraph (q)) (Eisner, 2013). In accordance with the testing guidelines the test was prolonged to 55 days since the biodegradation curve of the test item showed that biodegradation had started but the plateau had not been reached by Day 28. The per cent biodegradation of the test item was calculated based on the chemical oxygen demand of 1.54 mg O2/mg test item. The biochemical oxygen demand (BOD) of 1,2,3-Propanetriol, glycidyl ethers in the test media increased from test start until test termination after 55 days. At Exposure Day 28 and at test end after 55 days, the mean biodegradation of 1,2,3-Propanetriol, glycidyl ethers amounted to 13 % and 24 % of the COD, respectively. Consequently, the test substance was considered as not readily biodegradable under the test conditions. The pass level for ready biodegradability, i.e. biodegradation of at least 60 % of the COD in a 10‑day window within the 28‑day period of the test, was not reached. In the toxicity control containing both1,2,3-Propanetriol, glycidyl ethers and the reference item sodium benzoate, the run of the curve of the oxygen consumption over the 55‑day exposure period was similar but significantly higher than the one of the two procedure controls, containing only the reference item. Within 14 days of exposure, biodegradation amounted to 47 % and reaching 60 % at the end of the test at Day 55. Thus, according to the test guidelines, the test item had no inhibitory effect on activated sludge microorganisms at the tested concentration of 101 mg/L because biodegradation in the toxicity control was > 25 % within 14 days. In the procedure controls, the reference item was degraded by an average of 81 % by Exposure Day 14, thus confirming suitability of the activated sludge. At Day 28, the reference item was degraded by an average of 87 % and by 91 % at the end of test (Day 55).