2-Ethylhexanoic acid (EHA) was evaluated for subchronic toxicity to B6C3F1 mice (10/sex/group) administered dietary concentrations of 0, 0.1, 0.5, or 1.5% EHA for 90 days. No effect was noted on survival. Reduced body weight and food consumption was seen in the 1.5% groups. Increased liver weight was noted in the mid- and high-dose group, along with altered blood chemistry. The 90-day NOAEL was 0.1% EHA. Identical tests with rats led to similar effects, but only at the high-dose level. The 90-day NOAEL for rats was 0.5% EHA. In a developmental study, Fischer 344 rats (25 plug-positive females/group) were orally exposed by gavage to 0, 100, 250, or 500 mg/kg/day EHA in corn oil on gestation days 6 through 15. Maternal toxicity was noted in high-dose dams (ocular discharge, periocular encrustation, increased absolute and relative liver weights). In the high-dose group, fetal body weights/litter were decreased and fetal skeletal variations were increased. Exposure of New Zealand white rabbits (15 mated females/group) to oral doses of 0, 25, 125, or 250 mg/kg/day of EHA by gavage in corn oil on gestation days 6 through 18 led to maternal toxicity (1 mortality; 1 doe aborted) at 125 mg/kg/day and above. No embryotoxicity, fetotoxicity or teratogenicity was observed at any dose.