Groups of 10 male and 10 female of F344 rats (Charles River Japan, Inc.), six weeks old, received drinking water containing 0, 1110, 3330, 10000, 30000 or 90000 ppm 1,4-dioxane (>99.0%, Wako Pure Chemical Co., Tokyo) for 2 weeks. And groups of 10 male and 10 female of BDF1 mice (Charles River Japan, Inc.), six weeks old, received drinking water containing 0, 1110, 3330, 10000, 30000 or 90000 ppm 1,4-dioxane for 2 weeks.
