Initial Submission: Letter from Degussa Corp. to USEPA regarding Genotoxicity Tests of 1,3-Propanediol, with Attachments and Dated 02/22/1996

摘要

In each experimental group two parallel cultures were tested. 100 metaphases per culture were scored for structural chromosomal aberrations 18 h or 28 h (experiment II) after start of treatment. The following test concentrations were used: Experiment I , without SS mix- 18 h: 250, 1000, 2500 pg/mi; Experiment I, with 89 mix, 18 h: 500, 2500, 5000 pg/ml; Experiment II, without SS mix, 18 h: 375, 1250, 2500 pg/ml; Experiment II, without 89 mix- 28 h: 1250 pg/ml; Experiment II. with S9 mix, 18 h: 2500, 3750, 5000 pg/mi; and Experiment II, with S9 mix, 28 h: 5000 pg/ml. The concentrations of the test substance were determined from a pre-test for cytotoxicity. In the presence and absence of S 9 mix no toxic effects were observed up to the maximum recommended concentration of 5000 pgiml. However, in the cytogenetic experiments an evaluation was only possible up to concentrations of 1250 pgfmi (28 h) and 2500 pgiml (18 h) in the absence of metabolic activation due to low cell and metaphase numbers combined with poor metaphase quality at higher concentrations. Within the evaluated concentration ranges the mitatic indices were not substantially reduced.