The following abstract presents results of a study conducted by a contract laboratory for the National Toxicology Program. The findings were not evaluated in accordance with the levels of evidence for reproductive or developmental criteria established by NTP in March 2009. The findings and conclusions for this study should not be construed to represent the views of NTP or the U.S. Government.
2-Chloronitrobenzene (2CNB) is used in the synthesis of 2,4- dinitrochlorobenzene, 2-nitrophenol, and 2-nitroanaline which are used in the photographic, dye and lumber industries. 2CNB decreased sperm motility in B6C3F1 mice during inhalation exposure. Based on this preliminary suggestion of effect, 2CNB was tested for its effects on fertility and reproduction in Swiss CD-l mice according to the Continuous Breeding Protocol. Because inhalation Continuous Breeding studies are currently prohibitively expensive, 2CNB was administered via gavage.
In Task 1, dose levels of 20, 40, 80, 160, and 320 mg/kg/d were used. All animals in the high dose group died or were moribund and sacrificed. Animals in the 160 mg/kg/d group acclimated to the effects of 2CNB, and no animals died. The following dose levels were chosen for Task 2: 0, 40, 80 and 160 mg/kg b.wt.. Male and female mice (F0) were continuously exposed for a 7-day pre cohabitation and a 98-day cohabitation period. In the final litter of the holding period following the continuous breeding phase, pup weight gain during suckling was lower in the treated groups. At weaning, pups in the 160 mg/kg group weighed 12% less than controls. All other fertility and reproductive parameters were not affected.
F0 animals in the 160 mg/kg group had increased body and spleen weights and were methemoglobinemic. F1 animals (160 mg/kg) had significantly lower body weights at weaning but were significantly heavier than controls at mating and terminal necropsy. Spleen and liver weights were also increased in the treated F1 animals at necropsy, and blood analysis showed significant methemoglobinemia. Seminal vesicle-to-body weight ratio was significantly decreased in the F1 males. None of the fertility and reproductive parameters examined were affected by 2CNB treatment in F1 animals.
Overall, 2-chloronitrobenzene is not a reproductive toxicant, even in the presence of systemic toxicity, in Swiss CD-l mice.NTIS # PB92-187608/AS