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Key value for chemical safety assessment

Effects on fertility

Additional information

No guideline-compliant generation studies are available for 2,4-TDA.

2,4-TDA was investigated for effects on male fertility in a series of several feeding studies in Sprague- Dawley rats (Thysen et al. 1984; Thysen 1985 a, b; Varma et al. 1988). The studies revealed that the repeated oral intake of 2,4-TDA dose-dependently affects male fertility and spermatogenesis in rats. Dietary dose-levels of approximately 15 mg/kg bw/d over a 10 week period significantly reduced mating and fertility indices and produced obvious toxic effects on spermatogenesis (66% reduction) associated with a significant reduction in the weights of seminal vesicles and epididymides, morphological damage of Sertoli cells as well as with a diminished level of serum testosterone and an elevation of serum LH. Sperm count and testosterone levels remained low even after a recovery period of 11 weeks. Studies in male mice with oral doses of up to 80 mg/kg did not reveal effects on sperm or impairment of fertility.

Effects on developmental toxicity

Additional information

No guideline-compliant developmental toxicity studies are available for 2,4-TDA or the mixture 2,4/2,6-TDA. However, 2,4-TDA was investigated in a screening assay on 60 chemicals tested at one dose level only. Signs of clear-cut maternal toxicity was noted as 17 out of the 50 dams died and a significantly reduced mean body weight change was observed. In the surviving dams significant reduction of number of live litters (5 out of 20) as well as the number of live born per litter was observed. In the remaining offspring birth weight, weight gain, and viability through the first three postpartum days were not significantly different from that of the control group.

Justification for classification or non-classification