Registration Dossier

Administrative data

Description of key information

a valid 90 day and a valid 4 wks study conducted in mice are available:
Tributyl phosphate was administered in the diet to CD-1 mice (15/sex/group at study initiation) at concentrations of 0, 500, 2000, or 8000 ppm for ninety days. Control animals received standard laboratory diet. Physical observations, ophthalmoscopic examinations, body weight and food consumption measurements were performed on all animals pretest and on all surviving animals at selceted intervals during the treatment period. Hematology, clinical chemistry, and urinalysis were performed on selected animals at month 1 (day 30) and at study termination. After at least 90 days of treatment, all survivors were sacrificed, selected organs were weighed and organ/body and organ/brain weight ratios calculated. Complete gross mortem examinations and histopathological evaluation of selected tissues were conducted on all terminally sacrificed animals (10/sex/group).
A study designed to evaluate the toxicity of tributyl phosphate when administered in the diet to mice for up to 4 weeks and to select dose levels for a 90-day toxicity study and an oncogenicity study to be perfomed with this material.
Tributyl phosphate was administered orally, via dietary admixture, to CD-1 mice (5/sex/group) for at initial concentrations of 100, 1000, 5000, and 20000 ppm. However, because total mortality occured at the 20000 ppm level, the lowest dose was escalated from 100 ppm to 10000 ppm of test day 10 in order to provide a suitable range of dose levels. Control animals (5/sex/group) received standard laboratory diet.
Physical observations and body weight and food consumption measurements were performed on all animals pretest and at selected intervals during the treatment period. After at least 4 weeks of treatment, all survivors were sacrifieced, selected organs were weighed and organ/body and organ/brain weight ratios were calculated. Gross mortem examinations were conducted on all animals.

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Endpoint conclusion
Dose descriptor:
NOAEL
75 mg/kg bw/day

Additional information

In the 90 day study no effects of test material administration were evident in animals receiving the lowest concentration. NOEL = 500 ppm = 75 mg/kg bw for males and females.

In the 4 weeks study the no observed effect level (NOEL) of tributyl phosphate when administered in the diet to mice was 1.000 ppm (1000 ppm = 165-194 mg/kg/day for males, 226-271 mg/kg/day for females) and the lowest observed effect level (LOEL) was 5.000 ppm.

Justification for classification or non-classification

Based on these data a classification is not justified