Tris[4-(diethylamino)phenyl]methylium acetate

Endpoint summary

Additional information

The genetic toxicity was tested in three in vitro tests, one with ethylviolet acetate and two with a structural analogue ethylviolet chloride.

 

In an Ames test according to OECD Guideline 471, the structural analogue ethylviolet chloride was tested for its mutagenic potential based on the ability to induce back mutations in selected loci in several strains of Salmonella typhimurium (TA 1535, TA 1537, TA 98 and TA 100) (BASF AG, 1995a). Both a standard plate test (SPT, 5-1000 µg/plate) and preincubation test (PIT, 5-80 µg/plate) were performed with and without metabolic activation (Aroclor induced-rat liver S-9 mix).

Toxicity: A bacteriotoxic effect (reduced his- background growth, decrease in the number of his+ revertants) was observed in the standard plate test at doses >= 80 µg/plate. In the preincubation assay bacteriotoxicity was observed depending on the strain and test conditions from about 5-10 µg/plate onward.

Mutagenicity: An increase in the number of his+ revertants was not observed both in the standard plate test and in the preincubation test either without S-9 mix or after the addition of a metabolising system. According to the results of this study, the test substance is not mutagenic in the Ames test under the test conditions chosen.

 

In a chromosome aberration test according to OECD Guideline 473, the structural analogue ethylviolet chloride was tested for its ability to induce chromosome aberrations in Chinese hamster lung fibroblasts (V79) (BASF AG, 1995b). Test concentrations were 0.4 µg/ml, 0.6 µg/ml and 0.8 µg/ml culture medium (18 hours sampling time) and 0.8 µg/ml culture medium (28 hours sampling time) without metabolic activation or 2.0 µg/ml, 4.0 µg/ml and 6.0 µg/ml culture medium (18 hours sampling time) and 6.0 µg/ml culture medium (28 hours sampling time) in the experiment with metabolic activation. Duplicate cultures were used for all experimental groups.

The test substance did not cause any significant increase in the number of structurally aberrant metaphases incl. and excl. gaps either without S-9 mix or after adding a metabolising system in two experiments independent of each other. The types and frequency of aberrations were nearly in the range of that of the concurrent negative control values at both sampling times and within the range of the historical control data. The positive reference compound exhibited, as expected, a very clear clastogenic activity, both with and without metabolic activation, with a high proportion of exchanges.

 

In a gene mutation test according to OECD Guideline 476, ethylviolet acetate was tested for its potential to induce gene mutations at the hypoxanthine-guanine phosphoribosyl transferase (HPRT) locus in Chinese hamster ovary (CHO) cells in vitro (BASF SE, 2010c). Two independent experiments were carried out, both with and without the addition of liver S9 mix from induced rats (exogenous metabolic activation). The dose levels tested were:

- 1st Experiment: without S9 mix (4-hour exposure period): 0-0.200 μg/mL; with S9 mix (4-hour exposure period): 0-10.00 μg/mL;

- 2nd Experiment: without S9 mix (24-hour exposure period): 0-0.300 μg/mL; with S9 mix (4-hour exposure period): 0-10.00 μg/mL.

After an attachment period of 20-24 hours and a treatment period of 4 hours both with and without metabolic activation and 24 hours without metabolic activation, an expression phase of about 6-8 days and a selection period of about 1 week followed. The vehicle controls gave mutant frequencies within the range expected for the CHO cell line. Both positive control substances led to the expected increase in the frequencies of forward mutations. In both experiments in the absence and presence of metabolic activation the highest concentrations tested for gene mutations were not scorable due to clear cytotoxicity. On the basis from 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 adding a metabolising system in two experiments performed independently of each other.

Short description of key information:
Genetic toxicity studies were performed, showing that ethylviolet acetate and its structural analogue ethylviolet chloride are negative in an Ames test, an in vitro chromosome aberration and an in vitro gene mutation test.

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

Based on the available data, there is no concern for genotoxicity. Classification according to EU Directive 67/548/EEC and EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008 is therefore not warranted.