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A repeated-dose 28-day oral toxicity study was performed in the course of the Safety Examination of Existing Chemicals in Japan. DPPD was applied to rats at 0, 100, 300 and 1000 mg/kg bw/d via gavage for 28 consecutive days. The 0 and 1000 mg/kg group, respectively, were observed for 14 days following the last application to evaluate recovery of effects. The only relevant findings were significantly reduced food consumpation during week 4 in the males of the 300 mg/k group and during weeks 3 and 4 in the males of the 1000 mg/kg group. However, this was not accompanied by any effects on body weight or body weight gain. In addition, total bilirubin was significantly increased in the males of all treatment groups at the end of the treatment period. This increase had reversed at the end of the recovery period. No histopathological correlates were found in the liver, and bilirubin or urobilirubinogen levels in urine did not increase. Therefore, the NOAEL in this study is 1000 mg/kg bw/d.

In a long-term feeding study, Hasegawa et al. (1989) treated rats with DPPD via the diet (0.5 or 2% of DPPD) for 104 weeks. A LOAEL of 0.5% was observed in this study (corresponding to 194 mg/kg for males and to to 259 mg/kg for females).

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Additional information

Justification for classification or non-classification

Taking into account the available information, classification for repeated-dose toxicity is not required.