Naphthalene-2-sulphonic acid

Endpoint summary

Additional information

Valid experimental data were available to assess the genetic toxicity in vitro:

 

1.) Gene mutation in bacteria

Naphthalenesulfonic acids (purity 86%) were not mutagenic in a Ames test with and without metabolic activation according to OECD test guideline 471 (tested up to 5000 μg/plate in Salmonella typhimurium TA1535, TA 1537, TA 98 and TA 100; metabolic activation: S-9 mix from Aroclor 1254 induced rat liver; BASF AG 1989). The test was performed as independent standard plate test and preincubation test. Cytotoxicity (reduction of the background lawn) was not observed.

 

2.) Cytogenicity in mammalian cells

Naphthalenesulfonic acids (purity unknown) were tested for their potential to induce chromosomal aberrations in Chinese hamster lung cells (V79) in a GLP conform study according to OECD test guideline 473 (BAUA 1993). The test substance did not induce chromosomal aberrations with or without S-9 mix as exogenous metabolic activation system; the trials were performed up to toxic doses of 2500 µg/mL.

 

3.) Mammalian cell gene mutation assay

Naphthalinsulfonsaeureschmelze (NSS, purity 80 area-%) was tested in an in vitro GLP guideline study (BASF SE, 2010) for its potential to induce gene mutations at the HPRT locus in V79 cells with and without metabolic activation. Cytotoxicity (<= 50 % viability compared to vehicle control) was observed at >= 1875 µg/ml (without metabolic activation, 24 h treatment) or >= 468.8 µg/ml (with metabolic activation, 4 h treatment), respectively. Neither a relevant and reproducible increase in mutant colony numbers/10e6 cells nor a significant dose dependent trend of the mutation frequency was observed up to the maximum concentrations (2500 µg/ml without metabolic activation; 468.8 µg/ml with metabolic activation). Therefore, under the experimental conditions reported, NSS was considered to be non-mutagenic.

 

In vivo:

No data available.

Read across justification:

 

The registration item contains ca. 78.89% of naphthalene-2-sulphonic acid (CAS # 120-18-3) and ca. 6.5 % of naphthalene-1-sulphonic acid (CAS # 85-47-2). These two substances have the same molecular weight and are structurally almost identical. Therefore naphthalene-2-sulphonic acid and naphthalene-1-sulphonic acid and their respective salts are suitable for read across in order to fulfill the data requirements.

Short description of key information:
Gene mutation in bacteria
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100, with and without metabolic activation (Ames test): negative (OECD 471; BASF AG 1989)

Cytogenicity in mammalian cells
CHL V79 cells (chromosomal aberration test), without metabolic activation: negative (GLP, OECD 473; BAUA 1993)

In vitro mammalian cell gene mutation assay
HPRT assay, CHL V79 cells, with and without metabolic activation: negative (GLP, OECD 476, BASF SE 2010)

Mutagenicity in vivo
No data available

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

The test substance was not genotoxic in in vitro experiments using mammalian and bacterial cells. For naphthalenesulfonic acids, there is therefore no need for classification for mutagenic effects.