Benzenesulfonic acid, mono-C11-13-branched alkyl derivs., sodium salts

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vivo

Description of key information

The key study examined the potential of the test substance, analogue LAS acid, to cause mutations in the NMRI strain of mice. Mice (40 of males, 22-25 grams; 40 females, 20-25 grams) were exposure via oral gavage to a single dose of 1122 mg/kg bw.  After 72 hours, cells were taken from the thigh, purified by centrifugation and column chromatography,  Giemsa stained and evaluated for polychromatid erythrocytes (PCEs), the ratio of PCEs to normochromatid  erythrocytes and the number of cells with micronuclei.  No significant increase in the number of PEC with micronuclei were observed.  The test substance is considered negative (not mutagenic) in the mouse micronucleus test

Link to relevant study records

Reference

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus

Remarks:

Type of genotoxicity: chromosome aberration

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP laboratory study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)

GLP compliance:

yes (incl. QA statement)

Type of assay:

micronucleus assay

Species:

mouse

Strain:

NMRI

Sex:

male/female

Details on test animals or test system and environmental conditions:

Strain NMRI. Animals were approximately 22-26 g (male) and 20-25 g (female) and acclimated for 1 week to the test conditions (20 =/- 3 degrees C, 30-70% relative humidity, 12 hour light/dark cycle). Food was given daily and water was ad libitum. All animals were healthy at the time of test initiation.

Route of administration:

oral: gavage

Vehicle:

NaCl

Duration of treatment / exposure:

72 hours

Frequency of treatment:

single dose

Remarks:

Doses / Concentrations:
1122 mg/kg
Basis:
actual ingested

No. of animals per sex per dose:

40 males and 40 females per dose

Control animals:

yes

Positive control(s):

Endoxan (cyclophosphamid)

Tissues and cell types examined:

Cells were taken from the thigh.

Details of tissue and slide preparation:

Cells were mixed with cattle serum and suspended, then centrifuged. The sediment was then resuspended. The suspension was seperated in a cellulose chromatography column. This was centrifuged, and mixed with fetal calf serum and EDTA. This was air-dried for 24 hrs and stained with Giemsa.

Evaluation criteria:

number of polychromatid erythrocytes (PCE)
ratio of PCE to normochromatid erythrocytes (NCE)
number of cells with micronucleus

Sex:

male/female

Genotoxicity:

negative

Toxicity:

no effects

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

No significant increases in the number of polychromatic erythrocytes with micronuclei were observed.

Conclusions:

Interpretation of results (migrated information): negative
No significant increases in the number of polychromatic erythrocytes with micronuclei were observed.

Executive summary:

In a study with analogue LAS acid, no significant increases in the number of polychromatic erythrocytes with micronuclei were observed. The test substance is considered negative (not mutagenic) in the mouse micronucleus test.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Additional information

Additional information from genetic toxicity in vivo:

In cases where data on BABS Na is not available, data on analogue substances are used. The analogue substances included: 1) linear alkylbenezene sulfonate (commonly known as LAS), 2) the calcium salt of branched alkylbenzene sulfonate (commonly known as Branched CaDDBS) and 3) linear alkylbenzene sulfonic acid (commonly known as LAS acid). LAS is the sodium salt of linear alkylbenzene sulfonic acid with alkyl carbon chain lengths ranging from C10 to C13 and averaging 11.6. The primary structure is a C10 to C13 linear alkyl chain with a para-substituted benzene sulfonic acid sodium salt group attached at any of the secondary alkyl carbon positions. Branched CaDDBS is the calcium salt of branched alkylbenzene sulfonic acid with alkyl chain lengths ranging from C11 to C13. The primary difference between LAS and BABS Na salt is the alkyl chain, branched vs. linear. The primay difference between LAS and BABS Na salt is the alkyl chain, branched vs. linear. The primary difference between Branched CaDDBS and BABS Na salt is the salt, calcium vs. sodium. Because LAS Acid is neutralized in test medium or under physiological testing conditions, i.e. when tested in vivo, the primary differences between LAS Acid and BABS Na salt are the alkyl chains, branched vs. linear. Given their structural and functional similarities, LAS, Branched CaDDBS, and LAS acid are good analogues for read-accross for instances where data are available on them but not on BABS Na salt.

Three in vitro and one in vivo studies were available on analogues of BABS Na salt, including the branched calcium salt analogue (Branched CaDDBS), and a linear sodium salt (LAS) analogue. Ames studies on both Branched CaDDBS and LAS showed them to be non-mutagenic. A third study performed on LAS showed it to be non-mutagenic in mammalian cells. The key study examined the potential of the test substance, analogue LAS Acid, to cause mutations in the NMRI strain of mice. Mice (40 males, 22 -25 grams; 40 females, 20 -25 grams) were exposed via oral gavage to a single dose of 1122 mg/kg bw. After 72 hours, cells were taken from the thigh, purified by centrifugation and column chromatography, Giemsa stained and evaluated for polychromatid erythrocytes (PCEs), the ratio of PCEs to normochromatid erythrocytes and the number of cells with micronuclei. No significant increase in the number of PEC with micronuclei were observed. The test substance is considered negative (not mutagenic) in the mouse micronucleus test.

Justification for selection of genetic toxicity endpoint

Four studies on genetic toxicity were available on analogue substances.  All studies showed the analogue substances were non-mutagenic.  The key study was selected on the basis of it being the only in vivo study.

Justification for classification or non-classification

Based on the data available on LAS, Branched CaDDBS, and LAS acid, BABS Na salt is not classified for mutagenicity.