1,1,3,3-tetramethylguanidine

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Ames test. The study was performed in year 2015 according to GLP and OECD Guideline 471. No biologically relevant increases were observed in revertant colony numbers of any of the five test strains following treatment with LZ 754 at any concentration level, either in the presence or absence of metabolic activation (S9 Mix) in the performed experiments.

HPRT. The study was performed in 2018 according to GLP and OECD guideline 476. In the absence and the presence of metabolic activation, 1,1,3,3-Tetramethylguanidine is not a mutagenic substance in the HPRT locus assay using CHO cells.

MNT. The study was performed in 2017 according to GLP and OECD guideline 487. Under the experimental conditions reported, the test item did not induce micronuclei as determined by the in vitro micronucleus test in human lymphocytes. Therefore, 1,1,3,3-Tetramethylguanidine is considered to be non-mutagenic in this in vitro micronucleus test, when tested up to the highest required concentration.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Genetic toxicity in vitro:

Ames test according to OECD TG 471

The experiments were carried out using histidine-requiring auxotroph strains of Salmonella typhimurium (Salmonella typhimurium TA98, TAlO0, TA1535 and TA1537), and the tryptophan-requiring auxotroph strain of Escherichia coli (Escherichia coli WP2 uvrA) in the presence and absence of a post mitochondrial supernatant (S9) prepared :from livers of Phenobarbital/ß-naphthoflavone-induced rats.

The following test substance concentrations were applied: 5000; 1600; 500; 160; 50 and 16 μg/plate

In the Confirmatory Mutation Test, following pre-incubation procedure unequivocal signs of cytotoxicity were observed in all tested strains at the highest concentration level of 5000 μg/plate in absence and also in the presence of exogenous metabolic activation (±S9 Mix).

No biologically relevant increases were observed in revertant colony numbers of any of the five test strains following treatment with LZ 754 at any concentration level, either in the presence or absence of metabolic activation (S9 Mix) in the performed experiments.

The reported data of this mutagenicity assay shows that under the experimental conditions applied, the test item did not induce gene mutations by base pair changes or frameshifts in the genome of the strains used. -> no mutagenic activity.

HPRT test according to OECD TG 476

The substance 1,1,3,3-Tetramethylguanidine was assessed for its potential to induce gene mutations at the hypoxanthine-guanine phosphoribosyl transferase (HPRT) locus in Chinese hamster ovary (CHO) cells in vitro. Three independent experiments were carried out, three experimental parts with and two experimental parts without the addition of liver S9 mix from phenobarbital- and β-naphthoflavone induced rats (exogenous metabolic activation).

Following test substance concentrations were applied:

1st Experiment (4 hours treatment period): with or without S9 mix: 0; 75.00; 150.00; 300.00; 600.00; 1200.00 μg/mL

2nd Experiment (4 hours treatment period): with or without S9 mix: 0; 200.00; 400.00; 600.00; 800.00; 1200.00 μg/mL

3rd Experiment (4 hours treatment period): with S9 mix: 0; 300.00; 600.00; 800.00; 1000.00; 1200.00 μg/mL

The vehicle controls gave mutant frequencies within the range expected for the CHO cell line. Both positive control substances, ethyl methanesulfonate (EMS) and 7,12-dimethylbenz[a]-anthracene (DMBA), led to the expected statistically significant increase in the frequencies of forward mutations. In this study, in all experiments in the absence and the presence of metabolic activation no cytotoxicity was observed up to the highest concentrations evaluated for gene mutations. In both experiment in the absence of a metabolizing system no biologically relevant increase were observed in the mutant frequencies of cultures treated with the test substance up to the highest test concentration. All values were within the 95% level of the historical control values and statistically insignificant. Based on the results of the present study, the test substance did not cause any biologically relevant increase in the mutant frequencies either without S9 mix or after the addition of a metabolizing system.

MNT according to OECD TG 487

The test item 1,1,3,3-Tetramethylguanidine, dissolved in deionized water, was assessed for its potential to induce micronuclei in human lymphocytes in vitro in two independent experiments. In the absence and presence of S9 mix, no cytotoxicity was observed up to the highest applied and evaluated concentration. In the absence and presence of S9 mix, no relevant increases in the numbers of micronucleated cells were observed after treatment with the test item. In Experiment I, in the absence of S9 mix, however, two statistically significant increases were observed after treatment with 376 and 1152 μg/mL (0.95 and 0.90 % micronucleated cells, respectively). Since the values are clearly within the range of the historical control data and no dose-dependency was observed, the findings can be regarded as biologically irrelevant. In Experiment II, in the absence of S9 mix after treatment with 1152 μg/mL, the value of 1.08 % micronucleated cells slightly exceeded the range of the historical control data (0.12 – 1.03 %) and a dose-dependency was observed. Since this value is not statistically significant increased and the value of 1.08% micronucleated cells is clearly within the min-max range of the historical control data (0.05 – 1.35%), this finding can be regarded as biologically irrelevant. Appropriate mutagens were used as positive controls. They induced statistically significant increases in cells with micronuclei.

Genetic toxicity in vivo:

There are no in vivo mutagenicity studies with TMG available.

Justification for classification or non-classification

The available experimental test data (in vitro) are reliable and suitable for classification purposes under Regulation (EC) No 1272/2008. As a result the substance is considered not to be classified as mutagenic under the Regulation (EC) No 1272/2008.