Antifertility effects and dominant lethal assays for mutagenic effects of DEHP

Results of past animal studies have indicated the antifertility effects of phthalate esters and additional studies have suggested the potential mutagenic effects at very high doses. A toxicity study in mice has also been conducted in which chronic LD50 values were calculated for a group of phthalate esters. For DEHP, for example, the acute LD50 was 38.35 ml/kg, but after 10 weeks the value fell to 1.37 ml/kg, suggesting that the ester was producing a cumulative toxicity agent even at lower doses in regard to antifertility and mutagenic effects in mice. Preliminary results indicated that antifertility effects occurred with as little as three subcutaneous doses of 1 ml/kg each. Calculations of mutagenic index revealed a dose-dependent effect but no stoichiometric relationship was established.