Determination of the Biodegradability of the Test Sample Dc 1520 (eu) Silicone Antifoam According to the Oecd-guideline No. 301d with Cover Letter dated 04/20/94.

摘要

This study was conducted to assess the biodegradability of dimethyl siloxane emulsion and inhibiting action of the test substance on biodegradability of a reference material, according to OECD-guideline No. 301#D. The biodegradation of the test sample was tested by the inoculation of a solution made up of equal parts of total effluent from a sludge plant and a reflux from an activated sludge plant, with the addition of a standard soil suspension. Proper control and blanks were maintained. Biodegradability was assessed as chemical oxygen demand in the system measured after 5, 15, and 28 days. The inhibiting action of the test substance was assessed by measuring the degradation of sodium-N-dodecyl sulfate, a reference substance, in the presence of the test substance. The biodegradability of the test substance was determined to be 6.9%, 9.8%, and 11.2% after 5, 15, and 28 days, respectively. A negative value of -1.86 for the inhibition test was recorded; therefore, an inhibitory effect on the biodegradation of the reference substance can be assumed. From the results of this study, it was determined that the test sample is not readily biodegradable, and that the test sample has an inhibitory effect on biological degradation.