Tris(2-ethylhexyl) phosphate

リン酸トリス（2-エチルヘキシル）

CAS No. 78-42-2

Phosphoric acid tris (2-ethylhexyl) ester

リン酸トリス（2-エチルヘキシル）エステル

Molecular formula: C24H51O4P Molecular weight: 434.59

ABSTRACT

Tris(2-ethylhexyl) phosphate was studied for oral toxicity in a single dose toxicity test at a dose of 2000 mg/kg and in a 28-day repeat dose toxicity test at doses of 0, 30, 100, 300 and 1000 mg/kg/day. Genotoxicity of tris(2-ethylhexyl) phosphate was also studied by the reverse mutation assay in bacteria and the chromosomal aberration test in cultured Chinese hamster lung (CHL/IU) cells.

The single dose oral toxicity test revealed an LD50 of above 2000 mg/kg for both sexes.

In the repeat dose toxicity test, the prothrombin time was shortened in the 300 and 1000 mg/kg/day females, while the activated partial thromboplastin time was prolonged in the 1000 mg/kg/day males. These changes disappeared after a 14 day recovery period. The 300 and 1000 mg/kg males showed a decrease in serum cholinesterase activity even after the recovery period. The NOEL for repeat dose toxicity is considered to be 100 mg/kg/day.

Tris(2-ethylhexyl) phosphate was not mutagenic in Salmonella typhimurium TA100, TA98, TA1535, TA1537 and Escherichia coli WP2 uvrA. Neither structural nor numerical chromosomal aberrations were induced in CHL/IU cells up to the concentration going 50% cell growth inhibition or the limit concentration of 10 mM, in the absence or presence of an exogenous metabolic activation system.

SUMMARIZED DATA FROM THE STUDIES

1.Single Dose Oral Toxicity 1)

Purity : 99.7%
Test species/strain : Rat/Crj:CD (SD)
Test method : OECD Guideline 401
｡｡Dosage : 2000mg/kg
｡｡Number of animals : Male, 5; female, 5/group
GLP : Yes

｡｡Test results:

During the course of the study, no deaths occurred in both male and female groups, and no abnormalities that could be attributed to treatment with the test substance were detected in terms of general conditions, changes in body weight and pathological examination.

LD50: Male and female, >2000mg/kg

2. Repeat Dose Toxicity 1)

Purity : 99.7%
Test species/strain : Rat/Crj:CD (SD)
Test method : Guidelines for 28-Day Repeat Dose Toxicity Testing of Chemicals (Japan)
｡｡Route : Oral (gavage)
｡｡Dosage : 0 (vehicle), 30, 100, 300 and 1000mg/kg/day
｡｡Number of animals : Male, 6; female, 6/group
｡｡Vehicle : Sesame oil
｡｡Administration period : Male and female, 28 days
｡｡Terminal kill : Male and female, days 29 or 43
GLP : Yes
｡｡Test results:
The 300 and 1000mg/kg/day females showed a shortened prothrombin time, while the 1000mg/kg males exhibited a prolonged partial thromboplastin time. These changes disappeared after the recovery period. A decrease in serum cholinesterase activity was observed in the 300 and 1000 mg/kg males, which did not disappear after the recovery period of 14 days. No changes in general condition, body weight, food consumption, urinalysis and pathological findings, including histology, were observed. The test substance did not induce any toxic effects in the 30 and 100 mg/kg groups.

The NOEL for repeat dose toxicity is considered to be 100 mg/kg/day.

3. Genetic Toxicity

3-1 Bacterial test 2)

Purity : 99.7%
Test species/strains : S.typhimurium TA100, TA1535, TA98, TA1537 E. coli WP2 uvrA
Test method : Guidelines for Screening Mutagenicity Testing of Chemicals (Japan)
｡｡Procedures : Plate incorporation method
｡｡Solvent : Acetone
｡｡Positive controls
　		 :
　		 -S9, AF-2 (TA100, WP2, TA98), sodium azide (TA1535) and 9-aminoacridine (TA1537) +S9, 2-aminoanthracene (all strains)
｡｡Dosage : 0, 312.5, 625, 1250, 2500, 5000ｦﾌg/plate
｡｡S-9 : Rat liver, induced with phenobarbital and 5,6-benzoflavone
｡｡Plates/test : 3
｡｡Number of replicates : 2
GLP : Yes
｡｡Test results:
Minimum concentration of test substance at which toxicity was observed:
No toxicity was observed up to a concentration of 5000 ｦﾌg/plate with or without metabolic activation.

Genetic effects:
S. typhimurium TA100, TA1535, TA 98, TA1537

　 + ? -
with metabolic activation [ ] [ ] [*]
without metabolic activation [ ] [ ] [*]

E. coli WP2 uvrA

with metabolic activation [ ] [ ] [*]
without metabolic activation [ ] [ ] [*]

3-2 Non-bacterial in vitro test (chromosomal aberration test) 2)

Purity : 99.7%
Type of cell used : Chinese hamster CHL/IU cells
Test method : Guidelines for Screening Mutagenicity Testing of Chemicals (Japan)
｡｡Solvent : Acetone
｡｡Positive controls
　		 :
　		 -S9, Mitomycin C
+S9, Cyclophosphamide
｡｡Dosage

　		 :

　		 -S9 (continuous treatment): 0, 0.003, 0.006, 0.011 mg/ml
-S9 (short-term treatment): 0, 1.1, 2.2, 4.4 mg/ml
+S9 (short-term treatment): 0, 1.1, 2.2, 4.4 mg/ml
｡｡S-9 : Rat liver, induced with phenobarbital and 5,6-benzoflavone
｡｡Plates/test : 2
GLP : Yes
｡｡Test results:
Lowest concentration producing cytogenetic effects in vitro:
without metabolic activation (continuous treatment ): > 0.011 mg/ml
without metabolic activation (short-term treatment): > 4.4 mg/ml
with metabolic activation (short-term treatment): > 4.4 mg/ml
Genotoxic effects:
｡｡ clastogenicity polyploidy
　 + ? - + ? -
without metabolic activation: [ ] [ ] [*] [ ] [ ] [*]
with metabolic activation: [ ] [ ] [*] [ ] [ ] [*]
1)
　		 The tests were performed by the Research Institute for Animal Science in Biochemistry and Toxicology, 3-7-11 Hashimotodai, Sagamihara-shi, Kanagawa 229, Japan. Tel 81-427-62-2775 Fax 81-427-62-7979
2)
　		 The tests were performed by the Hatano Research Institute, Food and Drug Safety Center, 729-5 Ochiai, Hadano-shi, Kanagawa 257, Japan. Tel +81-463-82-4751 Fax +81-463-82-9627