Abstract
The developmental toxicity potential of butylparaben (CAS No. 94โ26โ8) was evaluated in rats. SpragueโDawley rats were administered butylparaben in 0.5% carboxymethylcellulose by oral gavage at dose levels of 0, 10, 100, or 1,000โmg/kg/day on gestation days (GD) 6โ19 (sperm positive day=GD 0). Caesarean sections were performed on GD 20 and fetuses were evaluated for viability, growth, and external, visceral, and skeletal abnormalities. Each group consisted of 25 females, with at least 21 per group being pregnant. The highest dose level caused decreases in maternal weight gain during some of the measurement intervals and was statistically significant during the GD 18โ20 interval. Maternal food consumption was significantly decreased in the highest dose group over the dosing period (GD 6โ20). There were no differences from control in any of the developmental parameters measured, including embryo/fetal viability, fetal weight, malformations, or variations. Based on the results of this study, the maternal NOAEL for butylparaben was 100โmg/kg/day. Butylparaben does not have the potential to cause developmental toxicity in the SpragueโDawley rat at oral dosages up to 1000โmg/kg/day. Birth Defects Res B 71:296โ302, 2004. ยฉ 2004 WileyโLiss, Inc.