Reaction products of 1H-Imidazole-1-ethanol, 4,5-dihydro-, 2-(C7-C9 odd-numbered alkyl) derivs. and sodium hydroxide and chloroacetic acid

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

One reliable study (Klimisch 1, OECD 471, GLP) showed no mutagenic activity of disodium caprylo amphodiacetate in the Ames test.

An MLA and a chromosome aberration study are available, performed with two members of the Amphoacetates category. Both studies had a negative outcome. DEREK NEXUS (version 5.0.2) did not find any substructures in its database that fired an alert for mutagenic potential for the chemical structures present in C8 Amphoacetates.

Link to relevant study records

Reference

Reference 1

Endpoint:

in vitro cytogenicity / chromosome aberration study in mammalian cells

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reason / purpose for cross-reference:

read-across source

Key result

Species / strain:

lymphocytes: human peripheral blood lymphocytes (HPBL)

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Positive controls validity:

valid

Conclusions:

A chromosome aberration study with Reaction products of 1H-Imidazole-1-ethanol, 4,5-dihydro-2-(C11 alkyl) derivs. and sodium hydroxide and chloroacetic acid (aqueous solution; amphoacetates C12) was performed according to OECD 473 guideline and GLP principles, in peripheral human lymphocytes in two independent experiments with and without metabolic activation. It is concluded that the substance is not clastogenic in human lymphocytes. This result is read across to the registered substance.

Executive summary:

In accordance with OECD 473 (1998), EU Method B.10 (2008) and according to GLP principles, a chromosome aberration study with Reaction products of 1H-Imidazole-1-ethanol, 4,5-dihydro-2-(C11 alkyl) derivs. and sodium hydroxide and chloroacetic acid (aqueous solution; amphoacetates C12) was performed in human peripheral blood lymphocytes in two independent experiments with and without metabolic activation. The dosing preparations were adjusted for the surfactant content of the substance and were set based on the observed toxicity in the dose range finding study (no precipitation was observed up to and including the top dose of 5000 µg/mL).

In the first cytogenetic assay, the cells were treated for 4 hr (with and without S9-mix) and for 20 hr (without S9-mix) with the substance at doses ranging from 30 to 250 µg/mL. In the second cytogenetic assay, the cells were treated for 4 hr (with S9 -mix) with the substance at doses ranging from 30 to 200 µg/mL.

Toxicity was reached at the dose levels selected for scoring. In all exposure groups, the percentage of cells with structural or numerical aberrations in the test substance-treated group was not significantly increased relative to solvent control at any dose level (p > 0.05, Fisher's Exact test). The number of cells with chromosome aberrations found in the solvent and positive control cultures was within the laboratory historical control data range.

No effects of the substance on the number of polyploid cells and cells with endoreduplicated chromosomes were observed both in the absence and presence of S9-mix.

Based on the results of this study, it is concluded that the substance does not disturb mitotic processes and cell cycle progression and is not clastogenic in human lymphocytes. This result is read across to the registered substance.

Reference 2

Endpoint:

in vitro gene mutation study in mammalian cells

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

In Section 13 of the IUCLID dossier, a report is attached in which the category approach is reported according to ECHA Guidance for the implementation of REACH, Guidance on information requirements and chemical safety assessment, Chapter R.6 (reporting format for a chemical category).

Reason / purpose for cross-reference:

read-across source

Key result

Species / strain:

mouse lymphoma L5178Y cells

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Untreated negative controls validity:

valid

Positive controls validity:

valid

Conclusions:

A mouse lymphoma assay was conducted with Alkylamidoamine glycinate, majority in C12 & 14 (amphoacetates C8-C18), in accordance with OECD 476 and according to GLP principles. It was concluded that the substance is not mutagenic in the TK mutation test system. This result is read-across to the registered substance.

Executive summary:

A mouse lymphoma assay was conducted with Alkylamidoamine glycinate, majority in C12 & 14 (amphoacetates C8-C18), in accordance with OECD 476 and according to GLP principles. The spontaneous mutation frequencies in the solvent-treated control cultures were between the minimum and maximum value of the historical control data range. Positive control chemicals, methyl methane sulfonate and cyclophosphamide induced appropriate responses. In the absence of S9-mix, Alkylamidoamine glycinate, majority in C12 & 14 (amphoacetate) did not induce a significant increase in the mutation frequency in the first experiment. This result was confirmed in a repeat experiment with modifications in the duration of treatment time. In the presence of S9-mix, Alkylamidoamine glycinate, majority in C12 & 14 (amphoacetate) did not induce a significant increase in the mutation frequency in the first experiment. This result was confirmed in an independent experiment with modifications of the S9-mix concentration added for metabolic activation. In conclusion, the substance is not mutagenic in the TK mutation test system. This result is read-across to Amphoacetates C8, member of the same chemical category.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

The mutagenic potential of disodium caprylo amphodiacetate, as Miranol J2M Freeze Dried, was assessed in the Salmonella typhimurium microsomal assay according to OECD 471 test guideline and in compliance with Good Laboratory Practice. The histidine-requiring S. typhimurium mutants TA 1535, TA 1537, TA 98, TA 100 and TA 102 were used in the presence and the absence of metabolic activation system from the liver fraction of Aroclor 1254-induced rats (S9-mix). Each strain was exposed to 5 dose levels. After 48 to 72 hours of incubation at 37°C, the revertant colonies were scored. The choice of the highest dose level for the main assay was based on the level of toxicity. All determinations were made in triplicate. Simultaneous negative (solvent) and positive controls were used in all experiments. A moderate to marked toxicity was noted without S9 mix at dose-levels ≥ 2500 µg/plate in the TA 1535, TA 1537 and TA 102 strains and at 5000 µg/plate in the TA 98 and TA 100 strains. With S9 mix, a moderate toxicity was noted in the TA 1535 strain in the first experiment (using the direct plate incorporation method) and a moderate to marked toxicity was noted at 5000 µg/plate in all the strains in the second experiment (using the preincubation method). The test item did not induce any noteworthy increase in the number of revertants, both with and without S9 mix, in any of the five strains. Positive controls gave the expected increases in the number of revertants, with and without S-9 mix. Under such experimental conditions, Miranol J2M Freeze Dried did not show mutagenic activity in the bacterial reverse mutation test with Salmonella typhimurium.

A mouse lymphoma assay was conducted with Alkylamidoamine glycinate, majority in C12 & 14 (amphoacetates C8-C18), in accordance with OECD 476 and according to GLP principles. The spontaneous mutation frequencies in the solvent-treated control cultures were between the minimum and maximum value of the historical control data range. Positive control chemicals, methyl methane sulfonate and cyclophosphamide induced appropriate responses. In the absence of S9-mix, Alkylamidoamine glycinate, majority in C12 & 14 (amphoacetate) did not induce a significant increase in the mutation frequency in the first experiment. This result was confirmed in a repeat experiment with modifications in the duration of treatment time. In the presence of S9-mix, Alkylamidoamine glycinate, majority in C12 & 14 (amphoacetate) did not induce a significant increase in the mutation frequency in the first experiment. This result was confirmed in an independent experiment with modifications of the S9-mix concentration added for metabolic activation. In conclusion, the substance is not mutagenic in the TK mutation test system. This result is read across to Amphoacetates C8, member of the same chemical category.

In accordance with OECD 473 (1998), EU Method B.10 (2008) and according to GLP principles, a chromosome aberration study with substance analogue Amphoacetates C12 was performed in human peripheral blood lymphocytes in two independent experiments with and without metabolic activation. The dosing preparations were adjusted for the surfactant content of the substance and were set based on the observed toxicity in the dose range finding study (no precipitation was observed up to and including the top dose of 5000 µg/mL). In the first cytogenetic assay, the cells were treated for 4 hr (with and without S9-mix) and for 20 hr (without S9-mix) with the substance at doses ranging from 30 to 250 µg/mL. In the second cytogenetic assay, the cells were treated for 4 hr (with S9 -mix) with the substance at doses ranging from 30 to 200 µg/mL. Toxicity was reached at the dose levels selected for scoring. In all exposure groups, the percentage of cells with structural or numerical aberrations in the test substance-treated group was not significantly increased relative to solvent control at any dose level (p > 0.05, Fisher's Exact test). The number of cells with chromosome aberrations found in the solvent and positive control cultures was within the laboratory historical control data range. No effects of the substance on the number of polyploid cells and cells with endoreduplicated chromosomes were observed both in the absence and presence of S9-mix. Based on the results of this study, it is concluded that the substance does not disturb mitotic processes and cell cycle progression and is not clastogenic in human lymphocytes. This result is read across to Amphoacetates C8.

In order to substantiate the read across, the representative mono- and di-acetate structures with C8 chain length were investigated with DEREK NEXUS (report attached in Section 13). No substructures were found in the amphoacetate representative structures that relate to mutagenicity or clastogenicity.

Justification for classification or non-classification

Based on the available data, no classification is warranted for genetic toxicity.