Disodium (Z)-4-(9-octadecenylamino)-4-oxo-2(or 3)-sulphonatobutyrate

Endpoint summary

Additional information

No data were available for registered substance, however data were available for read-across substance 'Butanoic acid, 4-amino-4-oxo-2(or 3)-sulfo-, N-(C16-C18 (even numbered), C18 unsaturated alkyl), disodium salts'. Justification for read-across with category members is provided in Section 13.

 

Bacterial mutation
The read-across test substance was tested in a key Ames test (Flügge, 2013d). Test item containing 25.5% active ingredient was examined in the 5 Salmonella typhimurium strains TA 98, TA 100, TA 102, TA 1535 and TA 1537 in two independent experiments, each carried out without and with metabolic activation. The first experiment was carried out as a plate incorporation test and the second as a preincubation test. The test item was suspended in aqua ad iniectabilia. A correction factor of 3.92 was used as the supplied test item contains 25.5% active ingredient only. The vehicle served as the negative control. From a preliminary test, cytotoxicity was noted at concentrations of 316 to 5000 µg/plate. Hence, 316 µg test item/plate were chosen as top concentration for the main study in the plate incorporation test and in the preincubation test. In the main test, six concentrations ranging from 1.0 to 316 µg test item/plate were employed in the plate incorporation test and in the preincubation test, each carried out without and with metabolic activation. No increase in revertant colony numbers as compared with control counts was observed for the test item, tested up to a cytotoxic concentration of 316 µg/plate, in any of the 5 test strains in two independent experiments without and with metabolic activation, respectively (plate incorporation and preincubation test). The positive control items showed a significant increase in the number of revertant colonies of the respective test strain and confirmed the validity of the test conditions and the sensitivity of the test system.

In conclusion, no mutagenic effect was exerted in bacterial strains without and with metabolic activation, therefore no mutagenic potential is expected for registered stubstance.

 

Mammalian gene mutation
In a key in vitro mammalian gene mutation study with read-across substance (Flügge, 2013e) test item containing 25.5% active ingredient was tested for mutagenic potential in a gene mutation assay in cultured mammalian cells (V79, genetic marker HPRT) both in the presence and absence of metabolic activation. The duration of the exposure with the test item was 4 hours or 24 hours in the experiments without S9 mix and 4 hours in the experiments with S9 mix. The test item was suspended in aqua ad iniectabilia. Aqua ad iniectabilia served as the vehicle control. In the preliminary test the concentration of 167 µg/mL caused complete cytotoxicity and test item precipitation. Hence, 125 µg active ingredient/mL were employed as the top concentration for the mutagenicity tests in the absence and in the presence of metabolic activation. Concentrations of 7.81, 15.63, 31.3, 62.5 or 125 µg active ingredient/mL were selected for the experiments without and with metabolic activation, respectively. The mutation frequency of the cultures treated were within the normal range of the vehicle controls. Under the present test conditions, the test item tested up to cytotoxic concentrations in the experiments without and with metabolic activation was negative in the HPRT-V79 mammalian cell mutagenicity test conditions where positive controls exerted potent mutagenic effects.

In conclusion, no mutagenic effect was exerted in mammalian V79 cells without and with metabolic activation, therefore no mutagenic potential is expected for registered stubstance.

 

Chromosomal aberration
A key in vitro micronucleus test was conducted with read-across substance using human peripheral lymphocytes both in the presence and absence of metabolic activation by a rat liver post-mitochondrial fraction (S9 mix) from Aroclor 1254 induced animals (Flügge, 2013f). The test was carried out with read-across test substance containing 25.5% active ingredient, employing 2 exposure times without S9 mix: (4 hours and 20 hours) and one exposure time with S9 mix ( 4 hours, repeated). The harvesting time was 24 hours after the end of exposure. Each treatment was conducted in duplicate. The test item was dissolved in aqua ad iniectabilia, which also served as the vehicle control. Based on a preliminary experiment, cytotoxicity was noted starting at the concentration of 250 µg active ingredient/mL. Hence, 255 µg/mL were employed as the top concentration for the main tests without and with metabolic activation (4-hour exposure), 125 µg/mL for the test without metabolic activation with 20 hour exposure. There was no increase in micronuclei up to the cytotoxic concentration when compared to control both with and without metabolic activation. Under the present test conditions, the test item tested up to cytotoxic concentrations, in the absence and in the presence of metabolic activation employing two exposure times (without S9) and one exposure time (with S9) revealed no indications of any chromosomal damage in the in vitro micronucleus test. In the same test, Mitomycin C and cyclophosphamide induced significant damage.

In conclusion, no chromosomal aberration was exerted in human peripheral lymphocytes without and with metabolic activationt, therefore no clastogenic potential is expected for registered stubstance.

 

Conclusion
Standard information requirements according to REACH Guidance Part 3 R7a were fulfilled for genotoxicity testing, including bacterial and mammalian mutagenicity and chromosomal aberration. Based on the available results, there were no indications of mutagenicity or genotoxicity, and no further testing is needed. The substance can be considered to have no mutagenic or genotoxic potential.

Justification for selection of genetic toxicity endpoint
Although the Ames bacterial mutagenicity test was selected, the mammalian gene mutation and chromosome aberration tests were equally important.

Short description of key information:
Data were available from read-across substance 'Butanoic acid, 4-amino-4-oxo-2(or 3)-sulfo-, N-(C16-C18 (even numbered), C18 unsaturated alkyl), disodium salts'. In a key Ames test no increase in mutations were observed in different Salmonella typhimurium strains with and without metabolic activation up to cytoxic concentration of 316 µg/plate. In a key mammalian gene mutation test in HPRT cells, the test item did not induce mutations in the absence and presence of metabolic activation when tested up to cytotoxic concentrations of 125 µg/mL. In a key in vitro Micronucleus study in human peripheral lymphocytes, there was no increase in micronuclei up to the cytotoxic concentration when compared to control both with and without metabolic activation up to cytotoxic concentrations of 255 µg/mL (4 h exposure) or 125 µg/mL (20 h exposure). There were no indications of any chromosomal damage in the in vitro micronucleus test. In the same test, Mitomycin C and cyclophosphamide induced significant damage.

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

Based on these results from structurally simliar read-across substance and according to the EC Directive (No.93/21/EEC) and CLP (No. 1272/2008 of 16 December 2008), the registered substance does not have to be classified and has no obligatory labelling requirement for genetic toxicity.