Dosing schedule: Each concentration was tested in duplicate with or without metabolic activation (S9), in two independent experiments Test method: OECD TG 473 Experiment 1 (repeat – see comment below): without S9, 0*, 78.13, 156.25, 312.5*, 625*, 1 250* ,2 500* 5 000* µg/mL; treatment/harvest time = 4/20 hours; positive control: ethyl methanesulphonate 750µg/mL; with S9, 0*, 39.06, 78.13, 156.25, 312.5*, 625*, 1 250*, 2 500* 5 000* µg/mL, treatment/harvest time = 4/20 hours, positive control: cyclophosphamide 25µg/mL; Experiment 2: without S9, 0*, 39.06, 78.13, 156.25, 312.5*, 625* 1 250*, 2 500* 5 000* µg/mL; treatment/harvest time = 20/20 hours; positive control: ethyl methanesulphonate 500µg/mL; with S9 (increased to a final concentration of 2%), 0*, 39.06 , 78.13, 156.25, 312.5*, 625* 1 250*, 2 500* 5 000* µg/mL; treatment/harvest time: 4/20 hours, positive control: cyclophosphamide 25 µg/mL; asterisk* indicates cultures selected for metaphase analysis Comment: An initial experiment (data not included in report) revealed: doses of 2 500 and 5 000 g/mL were probably beyond the maximum practical dose; an aberrant cell at the highest dose contained multiple aberrations; and weak responses in the positive control. The experiment was repeated. In the repeated Experiment 1 and Experiment 2, an oily layer was observed at and above 156.25 µg/mL and 312.5µg/mL in the presence and absence of metabolic activation, respectively. No toxicity was observed at any concentration. The test substance did not cause any significant increases in the incidence of cells with chromosomal aberrations, polyploidy or endoreplication, at the concentrations analysed in the presence or absence of metabolic activation. Positive controls used in the test caused significant FULL PUBLIC REPORT 26 April 2000 NA/713 Page 70 of 100
increases in the incidence of aberrant cells and the activity of the S9 fraction was found to be satisfactory. Result: C20-C24 alkenes, branched and linear was not considered to be clastogenic under the conditions of this chromosomal aberration test. FULL PUBLIC REPORT 26 April 2000 NA/713 Page 71 of 100