Reaction product of naphthalene, butanol, sulfonated and neutralized by caustic soda

Endpoint summary

Additional information

In vitro

Genetic toxicity of Reaction product of naphthalene, butanol, sulfonated and neutralized by caustic soda have been determined according the data on the substance and by a read-across approach based on analogue substance Reaction product of naphthalene, propan-2-ol, sulfonated and neutralized by caustic soda.

Studies on the substance :

Bacterial gene mutation:

Two studies (Klimish score 2) were available on the substance. One study was used as a key study and the other one used as supporting:

In the key study (BASF, 1992), the potential of the test item, Reaction product of naphthalene, butanol, sulfonated and neutralized by caustic soda, to induce reverse mutation in Salmonella typhimurium was studied. The test item was tested in two independent experiments, with and without a metabolic activation system, the S9 mix, prepared from a liver post‑mitochondrial fraction (S9 fraction) of rats induced with Aroclor 1254. The first experiment was performed according to the direct plate incorporation method and the second was performed according to the pre-incubation method (20 minutes). Four strains of bacteria Salmonella typhimurium TA 1535, TA 1537, TA 98 and TA 100 were used. Each strain was exposed to dose-levels of the test item. The selected dose-levels were: 60, 120, 100, 250, 500, 1000, 2000, 2500, 5000, 7500 µg/plate in the first test and 20, 100, 500, 1000, 2000 µg/plate in the second test. The number of mutations were scored. A bacteriotoxic effect was observed depending on the strain and test conditions from about 1000 µg – 2500 µg/plate onward.An increase in the number of his revertants was not observed both in the standard plate test and in the pre-incubation test either without S-9 mix or after the addition of the metabolizing system. In conclusion, the test item did not show any mutagenic activity in the bacterial reverse mutation test with Salmonella typhimurium, in the absence or in the presence of a rat metabolising system therefore Reaction product of naphthalene, butanol, sulfonated and neutralized by caustic soda is not classified according to Annex VI of the Directive 67/548/CEE and according to EU Regulation 1272/2008 (CLP).

In the supporting study (BAYER, 1983), the potential of the test item, Reaction product of naphthalene, butanol, sulfonated and neutralized by caustic soda, to induce reverse mutation in Salmonella typhimurium was studied. The test item was tested in two independent experiments, with and without a metabolic activation system, the S9 mix, prepared from a liver post‑mitochondrial fraction (S9 fraction) of rats induced with Aroclor 1254. Both experiments were performed according to the direct plate incorporation method. Four strains of bacteria Salmonella typhimuriumTA 1535, TA 1537, TA 98 and TA 100 were used. Each strain was exposed to five dose-levels of the test item (four plates/dose‑level). After 48 hours of incubation at 37°C, the number of mutations were scored. No cytotoxic effect was observed at doses up to 100 µg / plate. No significant mutagenic effect was observed for the four strains with and without metabolic activation.The number of mutations for the vehicle and positive controls was as specified in the acceptance criteria. In conclusion, the test item did not show any mutagenic activity in the bacterial reverse mutation test withSalmonella typhimurium, in the absence or in the presence of a rat metabolising system therefore Reaction product of naphthalene, butanol, sulfonated and neutralized by caustic soda is not classified according to Annex VI of the Directive 67/548/CEE and according to EU Regulation 1272/2008 (CLP).

Studies on an analogue substance :

Bacterial gene mutation:

Since the above-mentioned Ames test were conducted on 4 bacteria strains wheareas the current version of the OECD 471 guideline requires 5 strains (including S. typhimurium TA102 or E. Coli), the Ames test conducted on the analogue Reaction product of naphthalene, propan-2 -ol sulfonated and neutralized by caustic soda, was used as a supporting data.

In this study (CitoxLab, 2012), fully reliable and conducted according to OECD TG 471 and GLP, the test item did not induce any noteworthy increase in the number of revertants, either with or without S9 mix, in any of the five bacteria strains. Therefore, reaction product of naphthalene, propan-2-ol, sulfonated and neutralized by caustic soda was considered not to be mutagenic in this Salmonella typhimurium assay.

 

Mammalian gene mutation:

One fully reliable study is available (CitoxLab, 2012), conducted according to OECD TG 476 and GLP (mouse lymphoma assay, 6.25 – 400 µg/mL (active ingredient i.e. sodium mono, di and triisopropylnapthalenesulphonate), with and without liver microsomal activation, 3 and 24 h of treatment). The test item did not induce mutations in the thymidine kinase locus assay using the mouse lymphoma cell line L5178Y up to the highest tested concentrations. Therefore, reaction product of naphthalene, propan-2-ol, sulfonated and neutralized by caustic soda is considered not to be mutagenic in this mouse lymphoma assay.

 

Mammalian chromosome aberration:

One fully reliable study is available (CitoxLab, 2012) conducted according to OECD TG 473 and GLP (mouse lymphoma assay, with and without liver microsomal activation, 3-, 20- and 44-hour treatments). The dose-levels selected for the first experiment were 39.06, 78.13, 156.3, 312.5, 625, 1250, 2500 and 5000 µg/mL (active ingredient), both with and without S9 mix.

Based on the cytotoxicity observed in the first experiment, the dose-levels selected for the second experiment were as follows:

.            31.3, 62.5, 125, 250, 500 and 1000 µg/mL, without S9 mix,

.            62.5, 125, 250, 375, 500 and 750 µg/mL, with S9 mix.

No significant increase in the frequency of cells with structural chromosomal aberrations was noted in both experiments, at both harvest times and in both the absence and presence of S9 mix. Therefore, reaction product of naphthalene, propan-2-ol, sulfonated and neutralized by caustic soda is considered not to be clastogenic in this in vitro mammalian chromosome aberration assay.

 

In vivo

No data available. Based on REGULATION (EC) No 1907/2006 as at July 2011 and the absence of positive results in the three above mentioned in vitro tests no additional testing for genetic toxicity in vivo is necessary.  

 

Conclusion: 

For each endpoint (bacterial gene mutation, mammalian gene mutation, & mammalian chromosome aberration) reliable in vitro studies are available for the registered substance or a close analogue that all gave negative results.

Therefore it can be concluded that reaction product of naphthalene, butanol, sulfonated and neutralized by caustic soda

is neither clastogenic or aneugenic nor mutagenic.

Accordingly it can be concluded that reaction product of naphthalene, butanol, sulfonated and neutralized by caustic soda

is not genotoxic.

Justification for selection of genetic toxicity endpoint
No study was selected since all available in vitro studies were negative.

Short description of key information:
- genetic toxicity in vitro: negative; 2 studies negative (Genetic toxicity in bacteria) for sodium diisobutylnaphtalene sulfonate, 4 studies negative (Sire (2012) Genetic toxicity in bacteria - Chromosome aberration -Mammalian gene mutation) for the analogue Reaction product of naphthalene, propan-2 -ol sulfonated and neutralized by caustic soda,
- genetic toxicity in vivo: no data available

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

Harmonized classification:

No harmonized classification is available according to the Regulation (EC) No 1272/2008 including ATP3.

Self classification:

Five in vitro genotoxicity tests are available on the registered substance or a close analogue. None of the tests showed evidence of genotoxicity. The substance is therefore not regarded to have genotoxic effects and does not require classification for genetic toxicity according to the Regulation (EC) 1272/2008 and the Directive 67/548/EEC..