Reaction mass of 1,2-Benzenedicarboxylic acid, 4-sulfo-, trisodium salt, 1,2-Benzenedicarboxylic acid, 3-sulfo-, sodium salt (1:3), Sodium sulphate

Endpoint summary

Additional information

Genetic toxicity in vitro

Ames-Test

The test substance Produkt SPS was tested for its mutagenic potential based on the ability to induce point mutations in selected loci of several bacterial strains, i.e. Salmonella typhimurium and Escherichia coli, in a reverse mutation assay according to OECD 471 guideline and GLP (BASF SE, 2012).

STRAINS: TA 1535, TA 100, TA 1537, TA 98 and E. coli WP2 uvrA

DOSE RANGE: 33 μg - 5 300 μg/plate (SPT); 33 μg - 5 300 μg/plate (PIT)

TEST CONDITIONS: Standard plate test (SPT) and preincubation test (PIT) both with and without metabolic activation (liver S9 mix from induced rats).

SOLUBILITY: No precipitation of the test substance was found with and without S9 mix.

TOXICITY: A weak bacteriotoxic effect was occasionally observed depending on the strain only in the Standard plate test from about 2 650 μg/plate onward.

MUTAGENICITY: A relevant increase in the number of his+ or trp+ revertants was not observed in the standard plate test or in the preincubation test either without S9 mix or after the addition of a metabolizing system.

CONCLUSION: Thus, under the experimental conditions of this study, the test substance Produkt SPS is not mutagenic in the Salmonella typhimurium/Escherichia coli reverse mutation assay in the absence and the presence of metabolic activation.

HPRT-Test

The substance Produkt SPS 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 according to OECD 476 guideline and GLP (BASF, 2013). Three independent experiments were carried out, with and without the addition of liver S9 mix from phenobarbital- and β-naphthoflavone induced rats (exogenous metabolic activation).

According to an initial range-finding cytotoxicity test for the determination of the experimental doses the following doses were tested. 1st Experiment

without S9 mix (4-hour exposure period) (top dose too low)

0; 362.5; 725.0; 1450.0; 2900.0 μg/mL

with S9 mix (4-hour exposure period) (top dose too low)

0; 362.5; 725.0; 1450.0; 2900.0 μg/mL

2nd Experiment

without S9 mix (4 -hour exposure period)

0; 331.3; 662.5; 1325.0; 2 650.0; 5300.0 μg/mL

with S9 mix (4-hour exposure period)

0; 331.3; 662.5; 1325.0; 2 650.0; 5300.0 μg/mL

3rd Experiment

without S9 mix (24-hour exposure period)

0; 331.3; 662.5; 1325.0; 2650.0; 5300.0 μg/mL

with S9 mix (4-hour exposure period)

0; 750.0; 1500.0; 3000.0; 5300.0 μg/mL

The 331.3 μg/mL dose-levels were not evaluated.

Following attachment of the cells for 20-24 hours, cells were treated with the test substance for 4 and 24 hours in the absence of metabolic activation and for 4 hours in the presence of metabolic activation. Subsequently, cells were cultured for 6-8 days and then selected in 6 - thioguanine-containing medium for another week. Finally, the colonies of each test group were fixed with methanol, stained with Giemsa and counted.

The vehicle controls gave mutant frequencies within the range expected for the CHO cell line.

Both positive control substances, EMS and DMBA, led to the expected increase in the frequencies of forward mutations.

In this study in the absence and the presence of metabolic activation no cytotoxicity was observed up to the highest required concentration evaluated for gene mutations.

Due to a techniqual error while determining the top dose of the 1st Experiment, a repeat experiment, called 2nd Experiment was performed.

Based on the results of the present study, the test substance did not cause any relevant increase in the mutant frequencies either without S9 mix or after the addition of a metabolizing system in three independent experiments.

Thus, under the experimental conditions of this study, the test substance Produkt SPS is not mutagenic in the HPRT locus assay under in vitro conditions in CHO cells in the absence and the presence of metabolic activation.

In vitro Micronucleus Assay

The substance Produkt SPS was assessed for its potential to induce micronuclei in V79 cells in vitro (clastogenic or aneugenic activity) according to OECD 487 guideline and GLP (BASF SE; 2013). Two independent experiments were carried out, both with and without the addition of liver S9 mix from induced rats (exogenous metabolic activation).

Based on the observations and the toxicity data of a previously performed pretest for a HPRT study the following concentrations were tested and the test groups in bold type were evaluated:

1st Experiment

4 hours exposure; 24 hours harvest time; without S9 mix:

0; 165.6; 331.3; 662.5; 1 325.0; 2 650.0; 5 300.0 μg/mL

4 hours exposure, 24 hours harvest time, with S9 mix:

0; 165.6; 331.3; 662.5; 1 325.0; 2 650.0; 5 300.0 μg/mL

2nd Experiment

24 hours exposure, 24 hours harvest time, without S9 mix

0; 165.6; 331.3; 662.5; 1 325.0; 2 650.0; 5 300.0 μg/mL

4 hours exposure, 24 hours harvest time, with S9 mix

0; 1 325.0; 2 650.0; 3 975.0; 5 300.0 μg/mL

A sample of at least 1 000 cells for each culture were analyzed for micronuclei, i.e. at least 2 000 cells for each test group. Due to inhomogeneous data the sample of evaluation was increased up to 4 000 cells per test group in both experimental parts of the 1st Experiment.

The negative controls gave frequencies of micronucleated cells within our historical negative control data range for V79 cells. Both positive control substances, EMS and cyclophosphamide, led to the expected increase in the number of cells containing micronuclei.

In this study, no cytotoxicity indicated by clearly reduced relative increase in cell count (RICC) or proliferation index (PI) was observed up to the highest applied test substance concentration.

On the basis of the results of the present study, the test substance did not cause any biologically relevant increase in the number of cells containing micronuclei either without S9 mix or after adding a metabolizing system in two experiments carried out independently of each other.

Thus, under the experimental conditions described, Produkt SPS is considered not to have a chromosome-damaging (clastogenic) effect nor to induce numerical chromosomal aberrations (aneugenic activity) under in vitro conditions in V79 cells in the absence and the presence of metabolic activation.

Short description of key information:
Ames-Test (BASF, 2012): negative
HPRT-Test (BASF, 2013): negative
in vitro Micronucleus Assay (BASF, 2013): negative

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

Based on the available data, no classification and labeling is required (according to Directive 67/548/EEC and according to CLP) for genetic toxicity.