Reproductive and developmental toxicity studies of a linear alkylbenzene mixture in rats

Abstract

Alkylate 215, a mixture of linear decyl- to tridecylbenzenes, is an intermediate in the manufacture of detergent sulfonates. A two-generation reproduction study and a developmental toxicity study were conducted using single daily doses given by gastric intubation in a corn oil vehicle. In the reproduction study, groups of 30 rats/sex/group were given doses of 0, 5, 50, or 500 mg/kg/day. F 0 animals received a 10-week premating treatment period and were then mated to produce a single litter; F 1 adults were selected from the F 1 litters. F 1 animals were dosed for 11 weeks before mating to produce a single litter. Adults and weaned pups received a gross postmortem examination. Histopathology studies were conducted on reproductive tissues, tissues with gross lesions, and the pituitary gland taken from each adult in the control and high dose groups. In the developmental toxicity study, groups of 24 mated female rats were given 0, 125, 500, or 2000 mg/kg/day on Days 6 through 15 of gestation. Dams were terminated on gestation Day 20 and fetuses were examined for external, soft tissue, and skeletal defects. Results of the reproduction study were as follows. At 50 mg/kg/day, pup weights were decreased at Day 7 in the F 1 litter. At 500 mg/kg/day, decreases were found in the F 0 females in premating and early lactation weight gains; in both generations in premating weight gains in males and in weight gains during gestation in females; and in litter size, pup viability at birth, Day 0–4 survival, and pup weights on Days 14 and 21. The NOAEL for reproductive effects was 5 mg/kg/day. The developmental toxicity study found effects on several parameters. The only effect noted at 125 mg/kg/day was a slight decrease in maternal weight gain. Maternal weight gains were depressed to a greater extent at 500 and 2000 mg/kg/day. Ossification viriations and delayed ossification were increased significantly at 2000 mg/kg/day and were above control levels at 500 mg/kg/day. The NOAEL for developmental toxicity was 125 mg/kg/day. Alkylate 215 did not have any unusual or selective reproductive or developmental toxicity.