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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Remarks:
Type of genotoxicity: gene mutation
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1991
Report Date:
1991

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
GLP compliance:
yes
Type of assay:
bacterial forward mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material: sodium cocoyl isethionate (LB7819-1)
- Physical state: white waxy flakes
- Analytical purity: 72.45%
- Lot/batch No.: 1247
- Storage condition of test material: Stored at room temperature.
Test substance characterised and test solution concentrations verified by sponsor.
Aqueous SCI suspensions/solutions of 1.0, 14.0 and 36.0% were found to be stable over eight day period.

Method

Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Metabolic activation system:
Post mitochondrial supernatant (S9) prepared from livers of male Sprague Dawley rats induced with single ip injection of Arochlor 1254 at 500mg/kg.
Test concentrations with justification for top dose:
1.0, 3.3, 10, 33, 100 µg (+s9 mix)
10, 33, 100, 333, 1000 µg (-S9 mix)
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: water
Controls
Negative solvent / vehicle controls:
yes
Positive controls:
yes
Positive control substance:
2-nitrofluorene
Remarks:
Migrated to IUCLID6: 2- aminoanthracene, sodium azide
Details on test system and experimental conditions:
METHOD OF APPLICATION: in medium; in agar (plate incorporation); preincubation; in suspension; as impregnation on paper disk

DURATION
- Preincubation period: 20±2 minutes
- Exposure duration: 48 hours
Plates that were not counted immediately following the incubation period were stored at 4±2¿C until colony counting could be conducted.


SELECTION AGENT (mutation assays): Number of revertants



NUMBER OF REPLICATIONS: Each treatment was plated in triplicate.
Three independent experiments were conducted


NUMBER OF CELLS EVALUATED: 1.9 x 108 cells seeded per plate

Results and discussion

Test results
Key result
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
not specified
Vehicle controls validity:
valid
Positive controls validity:
valid

Any other information on results incl. tables

In experiment B1, no positive responses were observed in any of the tester strains in the presence or absence of metabolic activation.  As toxicity was only marginal at the highest dose without metabolic activation, the top dose was adjusted to 333 µg/plate for the subsequent confirmatory assays

In experiment B2, no positive responses were observed with tester strains TA98, TA1535 and TA1538.  Tester strains TA100 and TA1537 were not reported due to unacceptable titre values and were retested in experiment B3.

In experiment B3, no positive reactions were observed in TA100 and TA1537 in the presence or absence of metabolic activation.  A 2 fold non-dose responsive increase was observed with tester strain TA1537 in the absence of metabolic activation, however, it was considered that increases of this magnitude (less than 3 fold) with this strain and non-dose-responsive increases are not evaluated as positive.

Applicant's summary and conclusion

Conclusions:
Interpretation of results: Negative

The results of the assay, indicate that under the conditions of the study, the test article LB-7819-1 did not cause a positive response with any of the tester strains in the presence or absence of metabolic activation