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Description of key information

A Combined Repeated Dose Toxicity Study with the Reproduction/Developmental Toxicity Screening Test according to OECD TG 422 was performed with Tris-(2-ethylhexyl)amine in Wistar rats (BASF SE 2010). No NOAEL (no observed adverse effect level) for general, systemic toxicity of the test substance was determined for the F0 parental animals based on clinical-pathological and histopathological findings in all treated groups, predominantly dose-related histiocytic/mixed cell infiltrates in multiple organs (ovaries, intestines and their draining lymph nodes) which lead to secondary multiple local inflammatory reactions. Females were more sensitive than males. The LOAEL equals 125 mg/kg bw/d based on the described findings.
The oral administration of Tris-(2-ethylhexyl)amine via the diet to male and female Wistar rats for 3 months (BASF SE, 2014) revealed test substance-related adverse signs of systemic toxicity at a concentration of 2000 ppm in male and of 300 ppm in female Wistar rats. The NOAEL was 300 ppm in male (19 mg/kg bw/d) Wistar rats, a NOAEL in females was not achieved and below 300 ppm (<21 mg/kg bw/d) taking findings in ovaries and mesenteric lymph nodes into account.

Key value for chemical safety assessment

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

In a GLP guideline study according to OECD 422, Tris-(2-ethylhexyl)amine was administered as a constant homogeneous addition to the food at concentrations of 1500, 4000 and 12000 ppm to groups of 10 male and 10 female Wistar rats (BASF SE, 2010). These concentrations in feed correspond to about 105, 277 and 815 mg/kg bw/d in males; 103, 271, 770 mg/kg bw/d in non-pregnant females; 121, 306 and 918 mg/kg bw/d in pregnant females and 173, 455, 1098 mg/kg bw/d in lactating females. The control group, consisting of 10 male and 10 female Wistar rats, was kept on basal diet only. The duration of treatment covered a 2-week premating and a mating period in both sexes, approximately 1 week post-mating in males, and the entire gestation period as well as 4 days of lactation and approximately 1 week thereafter in females.

Clinically, toxicity was noted in the F0 males and F0 females at 4000 and 12000 ppm. Salient clinical findings were decreases in food consumption and body weights/ body weight gain which were most severe in females during gestation and lactation and led to a minimally lower mean terminal body weight in females administered 12000 ppm.

Detailed clinical examinations in an open field, detailed observations in a functional observational battery (FOB) and measurements of motor activity did not reveal any indications of test substance-induced effects in low-, mid- and high-dose rats.

Clinical pathology revealed that in all dosed female rats the absolute neutrophil and monocyte counts and correspondingly the total white blood cell counts were elevated. The increased serum ALT activities in female and male rats of the high dose group (12000 ppm) indicated a slight degradation of the liver cell membranes. The lower albumin levels in females of high and mid dose group could be interpreted as an altered liver cell metabolism in these animals.

Treatment led to minimally lower mean terminal body weight in females administered 12000 ppm and to prominent, dose-related ovary weight increases in all treated female groups. Other minor organ weight increases considered to be test substance-related were observed for the spleen, adrenal gland, liver and kidney, predominantly in the females, but were not clearly dose-related. Test substance-related macroscopic organ changes were seen in the females, only, and mainly comprised enlarged ovaries in all dose groups and enlarged spleen and/or mesenteric lymph node in occasional females treated at 4000 or 12000 ppm.

Predominant histopathological findings were dose-related histiocytic/mixed cell infiltrates in multiple organs, with an overall tendency of being more severe in the females. In the small intestine, minimal villous infiltrates of histiocytes and/or mixed cells were seen in some males and females treated at 12000 ppm and in single females of the lower dose groups. In individual females, these small intestinal changes were accompanied by minimal focal abscess(es)/necrotic foci and/or mural histiocytic/mixed cell infiltrates. Histiocytic/ mixed cell infiltrates were also seen in the Peyer's patch in a dose-related manner in some females treated at 4000 or 12000 ppm and in one male treated at 12000 ppm. Moreover, dose-related minimal to massive degrees of histiocytic/mixed cell infiltrates were noted in the mesenteric lymph node (draining lymph node of the small intestine) in the majority of males and females of all dose groups, in some animals together with lymphoid hyperplasia, abscesses/necrotic foci and/or adjacent mixed cell infiltrates. The axillary, mediastinal and/or liver lymph node of single females administered 12000 ppm showed similar findings. In the stomach, minimal or slight degrees of a focally extensive submucosal edema/ inflammation were observed in a proportion of males and females treated at 4000 or 12000 ppm. The urinary bladder of a single female treated at 12000 ppm showed minimal mural histiocytic/mixed cell infiltrates, which were also considered test substance-related. In the corpora lutea of the ovary, a prominent foamy change with mixed cell inflammation was observed in all test substance-treated females, the mean severity of the change being clearly dose-related. The infiltrates in the small intestine, draining lymph nodes and other organs might represent histiocytes containing test substance-lipid complexes which are poorly degraded by lysosomal enzymes and lead to a secondary local inflammatory reaction. Ovarian changes might also represent storage of test substance-lipid complexes with inflammation.

Thus, no NOAEL for general, systemic toxicity was determined for the F0 parental animals based on clinical-pathological and histopathological findings in all treated groups, predominantly dose-related histiocytic/mixed cell infiltrates in multiple organs (ovaries, intestines and their draining lymph nodes).

In a GLP guideline study according to OECD 408, Tris-(2-ethylhexyl)amine was administered via the diet to groups of 10 male and 10 female Wistar rats at concentrations of 0 (test group 0), 300 (test group 1), 2000 (test group 2) and 12000 ppm (test group 3) over a period of 3 months (BASF SE, 2014). Signs of general systemic toxicity were only observed in males by an impairment of body weight data at the high dose. In rats of both sexes of test group 3 (12000 ppm) increased alanine aminotransferase activities indicated some slight degradation of liver cell membranes. In females of this test group higher γ-glutamyl transferase activities and lower albumin levels were observed. Additionally, in females of test group 3 (12000 ppm) a systemic inflammation can be assumed because of higher absolute total white blood cell as well as absolute neutrophil, lymphocyte and monocyte cell counts. Regarding pathology, the ovaries, the digestive tract with draining lymph nodes (mesenteric lymph nodes) and in females only the spleen and bone marrow were the target organs. In general, females were more severely affected than males. The liver weight increase in female animals was most likely test substance-related. There was no histopathologic finding in test group 3 (12000 ppm) females that could explain the weight increase. The spleen weight increase in females of test group 2 and 3 (2000 and 12000 ppm) possibly was related to the macroscopic observed increase in spleen size in two females of test group 3 (12000 ppm). Furthermore, histopathologically extramedullary hematopoiesis was observed in the spleen which also could have contributed to the weight increase. These findings were regarded to be a consequence to the inflammatory processes in animals of these test groups and to be adverse. The increased organ weight and macroscopically increased size in ovaries corresponded to the granulomatous inflammation (histiocytic/mixed cell infiltrates, fibrosis, multinucleated giant cells, foamy change) observed in animals of test group 2 and 3 (2000 and 12000 ppm). In test group 1 (300 ppm) were still two animals showing minimal histiocytic infiltrates within the corpora lutea. This finding was dose related and regarded to be adverse. In the digestive tract, mainly the jejunum, histiocytic/mixed cell infiltrates were observed in males and females of test group 2 and 3 (2000 and 12000 ppm) in the tips of the villi and in the wall of the digestive tract. This finding was dose related and regarded to be test substance-related and adverse. The mesenteric lymph nodes of males and females revealed a dose-response related granulomatous inflammation (histiocytic/mixed cell infiltrates, fibrosis, multinucleated giant cells). These findings corresponded to the macroscopically observed enlargement in female animals. In females of test group 1 (300 ppm) still one animal was affected. These findings showed a dose-response relationship and were regarded to be test substance-related and adverse. Similar findings as in the mesenteric lymph nodes were observed in the renal lymph nodes of three females in test group 3 (12000 ppm) which corresponded to the macroscopically observed enlargement. It can be hypothesized that the infiltrates in the small intestine and draining lymph nodes might represent histiocytes containing test item-lipid complexes which are poorly degraded by lysosomal enzymes and lead to a secondary local inflammatory reaction with signs of foreign body reaction (multinucleated giant cells). Ovarian changes might also represent storage of test item-lipid complexes (foamy change) with inflammation. In the bone marrow of three females of test group 3 (12000 ppm) there was an increase in myelopoiesis. This finding was regarded to be a consequence to the inflammatory processes taking place in several organs and was therefore regarded to be secondary and not adverse.

Therefore, the NOAEL was 300 ppm in male (19 mg/kg bw/d) Wistar rats. A NOAEL in female Wistar rats was not achieved and below 300 ppm (<21 mg/kg bw/d) taking findings in ovaries and mesenteric lymph nodes into account.

Justification for classification or non-classification

Dangerous Substance Directive (67/548/EEC)

The available experimental test data are reliable and suitable for the purpose of classification under Directive 67/548/EEC. Based on the data, classification for repeated dose toxicity is warranted (R48/22).

 

Classification, Labeling, and Packaging Regulation (EC) No. 1272/2008

The available experimental test data are reliable and suitable for the purpose of classification under Regulation (EC) No.1272/2008. Based on the data, classification for repeated dose toxicity is warranted (STOT RE cat. 2, H373).