Subchronic oral toxicity of tributoxyethyl phosphate in the Sprague-Dawley rat

The effects of the widely used alkyl phosphate, tributoxyethyl phosphate (TBOP), were investigated in male and female Sprague-Dawley rats. This chemical was administered (low dose: 0.25 ml/kg X day; high dose: 0.50 ml/kg X day) by gavage once a day for 5 days/wk, over a period of 18 wk. Histopathological examination of tissues in treated male rats showed the presence of cardiac lesions, including myocardial necrosis with inflammatory cell infiltration. This study indicated that oral administration of TBOP may have caused or contributed to the early onset of a common background finding in this rat strain.