Tripropylamine

Endpoint summary

Additional information

Ames Test

In a key study, tri-n-propylamine was tested for its mutagenic activity in the Salmonella - Escherichia coli/Mammalian-Microsome Reverse Mutation Assay. The tester strains used in the mutagenicity assay were Salmonella typhimurium tester strains TA98, TA100, TA1535, TA1537, and Escherichia coli tester strain WP2uvrA. The assay was conducted with five doses of the test article in the presence and the absence of S9 mix along with concurrent vehicle and positive controls using three plates per dose. The doses tested were 0, 20, 100, 500, 2500, 5000 µg/plate in the standard plate test (Salmonella typhimurium and E. coli) and 0, 4, 20, 100, 500, 2500 µg/plate (Salmonella typhimurium) and 0, 20, 100, 500, 2500, 5000 µg/plate (E. coli) in the preincubation test. The experiments were performed in the presence and absence of S9 mix.

The results show that, under the conditions of this study, tri-n-propylamine did not cause a positive increase in the number of revertants per plate of any of the tester strains either in the presence or absence of microsomal enzymes prepared from Aroclor™-induced rat liver (S9).

In another key study, tri-n-propylamine was tested for mutagenic activity in the Salmonella - Escherichia coli/Mammalian-Microsome Reverse Mutation Assay (Hoecst Celanese, 1996; Report No. 17725 -0 -409). The doses tested in the mutagenicity assay were selected based on the results of a dose rangefinding study using tester strains TA100 and WP2uvrA and ten doses of test article ranging from 5,000 to 6.67 µg per plate, one plate per dose, both in the presence and absence of S9 mix. The tester strains used in the mutagenicity assay were Salmonella typhimurium tester strains TA98, TA100, TA1535, TA1537, and Escherichia coli tester strain WP2uvrA. The assay was conducted with five doses of test article in both the presence and absence of S9 mix along with concurrent vehicle and positive controls using three plates per dose. The doses tested were 5,000, 3,330, 1,000, 333, and 100 µg per plate in both the presence and absence of S9 mix.

The results show that, under the conditions of this study, tri-n-propylamine did not cause a positive increase in the number of revertants per plate of any of the tester strains either in the presence or absence of microsomal enzymes prepared from Aroclor™-induced rat liver (S9).

Micronucleus Test (OECD 487)

Tri-n-propylamine was tested in an in vitro micronucleus assay using duplicate human lymphocyte cultures prepared from the pooled blood of two female donors in a single experiment (Covance Laboratories, 2012a; Report No. 8260609). Treatments covering a broad range of concentrations, separated by narrow intervals, were performed both in the absence and presence of metabolic activation (S-9) from Aroclor 1254 induced animals. The test article was formulated in acetone and the highest concentration tested in the Micronucleus Experiment, 1433 µg/mL (equivalent to 10 mM), was determined following a preliminary cytotoxicity Range-Finder Experiment. Treatments were conducted (as detailed in the following summary table) 48 hours following mitogen stimulation by phytohaemagglutinin (PHA). The test article concentrations for micronucleus analysis were selected by evaluating the effect of Tri-n-propylamine on the replication index (RI). In the Micronucleus Experiment, micronuclei were analysed at three or four concentrations. Appropriate negative (vehicle and untreated) control cultures were included in the test system under each treatment condition. The proportion of micronucleated binucleate (MNBN) cells in these cultures fell within current historical vehicle control (normal) ranges. Positive control substances induced statistically significant increases in the proportion of cells with micronuclei and therefore were all employed as clastogenic and aneugenic chemicals. All acceptance criteria were met and the study was therefore considered as valid.

Treatment of cells with Tri-n-propylamine in the absence and presence of S‑9 resulted in frequencies of MNBN cells, which were similar to and not significantly higher from those observed in concurrent vehicle controls for all concentrations analysed. The MNBN cell frequency of all treated cultures fell within normal ranges. It is concluded that Tri-n-propylamine did not induce micronuclei in cultured human peripheral blood lymphocytes following 3+21 hour treatment in the absence and presence of a rat liver metabolic activation system (S‑9) when tested up to 1433 mg/mL (equivalent to 10 mM, a recommended regulatory maximum concentration for in vitro cytogenetic assays) and following 24+0 hour treatment in the absence of S-9 when tested up to cytotoxic concentrations.

Mouse Lymphoma Assay (OECD 476)

Tri‑n‑propylamine was assayed for the ability to induce mutation at the hypoxanthine‑guanine phosphoribosyl transferase (hprt) locus (6-thioguanine [6TG] resistance) in mouse lymphoma cells using a fluctuation protocol (Covance Laboratories, 2012b; Report No. 8260610). The study consisted of a cytotoxicity Range-Finder experiment followed by two independent experiments, each conducted in the absence and presence of metabolic activation by an Aroclor 1254 induced rat liver post‑mitochondrial fraction (S‑9). The test article was formulated inacetone. A 3 hour treatment incubation period was used for all experiments.

In the cytotoxicity Range-Finder Experiment, six concentrations were tested in the absence and presence of S‑9, ranging from 44.67 to 1429 mg/mL (equivalent to approximately 10 mM at the highest concentration tested). The highest concentration to provide ≥10% relative survival (RS) was 714.7 µg/mL, which gave 56% and 80% RS in the absence and presence of S‑9, respectively.

In Experiment 1 nine concentrations, ranging from 300 to 1433 µg/mL, were tested in the absence and presence of S‑9. Seven days after treatment the highest concentration selected to determine viability and 6TG resistance was 1300 µg/mL, which gave 6% and 5% RS in the absence and presence of S‑9, respectively.Steep concentration‑related toxicity was observed in the absence and presence of S-9 such that no concentration gave 10%‑20% RS. In the absence of S-9, cultures treated at 1050 and 1300 µg/mL gave 55% and 6% RS, respectively and in the presence of S-9, cultures treated at 1150 and 1300 µg/mL gave 32% and 5% RS, respectively. The lower and higher concentrations were analysed under both treatment conditions.

In Experiment 2, ten concentrations, ranging from 300 to 1433 µg/mL, were tested in the absence and presence of S‑9. Sevendays after treatment the highest concentration analysed to determine viability and 6TG resistance was 1433 µg/mL, which gave 12% RS in both the absence and presence of S‑9.

Negative (vehicle) and positive control treatments were included in each Mutation Experiment in the absence and presence of S‑9. Mutant frequencies in negative control cultures fell within acceptable ranges and clear increases in mutation were induced by the positive control chemicals 4‑nitroquinoline 1-oxide (without S‑9) and benzo(a)pyrene (with S‑9). Therefore the study was accepted as valid.

In Experiments 1 and 2, no statistically significant increases in mutant frequency were observed following treatment with tri‑n‑propylamineat any concentration tested. A weak but significant linear trend was observed in the presence of S-9 in Experiment 2. However, in the absence of any significant increases in mutant frequency at any concentration analysed in this experiment and no reproducibility of the effect between experiments, this isolated observation was considered not biologically relevant.

It is concluded that tri‑n‑propylamine did not induce mutation at the hprt locus of L5178Y mouse lymphoma cells when tested under the conditions employed in this study. These conditions included treatments up to highly toxic concentrations in two independent experiments in the absence and presence of a rat liver metabolic activation system (S‑9).

Justification for selection of genetic toxicity endpoint
No study is selected since all three in vitro studies (required under REACH) were negative.

Short description of key information:
The target substance tripropylamine is considered as non-mutagenic when tested in Ames Test (study design is similar to OECD 471, GLP) and in Mouse Lymphoma Assay (L5178Y cells) according to OECD 476 and GLP . Tripropylamine revealed no clastogenic activity when tested in cultured human peripheral lymphocytes cells according to OECD 487 and GLP.

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

Tripropylamine was negative in all genotoxicity tests required under REACH. No classification and labelling are needed for this endpoint according to the Regulation (EC) No. 1272/2008.