Diethylbenzene

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Description of key information

Assessment of reproductive organs from 13 week inhalation study on Mixed DEB; A OECD 422 conducted using 1,4-DEB (a constituent of mixed DEB)

Additional information

Repeated inhalation exposure up to 1400 mg/m3 of DEB mixed isomers for 13 weeks did not result in any histopathological effects in reproductive organs of male or female Sprague-Dawley rats. There are no additional data available on the mixed isomers, however there is a study available on one of the isomers (1,4 -DEB) conducted by the Japanese ministry of Health.

In a combined repeat dose/reproductive/developmental toxicity screening test, Sprague-Dawley rats (12/sex/dose) were administered the supporting chemical, 1,4-diethylbenzene, via gavage at 0, 30, 150 or 750 mg/kg-bw/day. Males were dosed for 44 days, including 14 days before mating and females from 14 days before mating until Day 3 of lactation. Male and female copulation and fertility indices, pregnancy rates, and implantation sites were comparable among groups. The number of live and dead pups, the number of litters with live offspring, the mean litter size and the male-to-female ratio were comparable among the groups on lactation day 0. There were no differences in mean pup weights across groups. No differences were noted in external observations; and no remarkable findings were observed at necropsy in pups found dead prior to lactation day 4. Duration of gestation was slightly, but statistically significantly (p not stated), increased at 750 mg/kg-bw/day and there was a statistically significant (p not stated) decrease in pup survival on day 4 at 750 mg/kg-bw/day. The investigators did not consider these findings treatment-related therefore the NOAEL for systemic and reproductive toxicity is 750 mg/kg bw/day.

Effects on developmental toxicity

Description of key information

Oral Gavage Developmental toxicity study in rats using mixed isomers of DEB

Additional information

In a well-conducted prenatal developmental study in rats (20, 100, 200 mg/kg bw/d) oral gavage dosing of DEB mixed isomers did not produce any indication of developmental toxicity although there was a slight reduction noted in fetal body weight at doses (200 mg/kg bw) that also caused a decrease in maternal body weight (6%). Due to a decrease in food consumption and maternal bodyweight at 100 and 200 mg.kg bw.day the NOEL for maternal effects was listed as 20 mg/kg bw/day and the developmental NOEL was 100 mg/kg bw (due to a decrease in fetal weight attributed to decrease in maternal food consumption and bw).

Justification for classification or non-classification

In the available studies there were no effects observed on reproductive performance or on Developmental toxicity (at doses not maternally toxic). Therefore there is no justification for classifcation as a reproductive or developmental toxicant.