Toxicology of Industrial Compounds

288 TESTING AND EVALUATION FOR REPRODUCTIVE TOXICITY
Table 20.5 OECD 422: DEHP, tabular summary
Notes:
[] Treatment at 2000 mg kg −1 was withdrawn after mating (4 weeks of treatment)
due to loss of condition and mortality of females.
pp=post partum.
Bold type indicates treatment effects on spermatogenesis at 2000 mg kg −1 . There is
a marked reduction in the number of pregnancies. At lower dosages an increased
duration of pregnancy, reduced litter size and litter weight, indicates an effect on
the female and or offspring. The higher mean pup weights are consequent to the
longer duration of pregnancy.
offspring. No effects on spermatogenesis were reported but, if a dosage
inducing effects on the male had been selected, all the females would have
died.
With EGME (Table 20.7), dosages were based on acute toxicity and
limited repeat dose toxicity studies only. This provided a more realistic
representation of the testing of a new substance. The first consequence was
the occurrence of systemic toxicity at 500 and 1000 mg kg −1 . Treatment at
the high dosages had to be withdrawn prior to mating, investigating
recovery became a new objective. At 100 mg kg −1 profound effects on
spermatogenesis were evident. Some pregnancies were obtained, but no live
young were born. For the high dosage groups, effects on males remained
evident several weeks after withdrawal of treatment. The duration of
pregnancy was increased. A consequence of this is the higher mean pup
weight. Values for numbers of implantations, live young and litter weight
were lower than control values. So, not only did the test show the
anticipated effects on reproduction, it also demonstrated that recovery of