Stearamide

Genetic toxicity: in vitro

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:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP guideline study with acceptable restrictions. Incomplete strain selection, but adequate at the time of testing.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1989

Report date:

1989

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

Incomplete strain selection: TA-102 or equivalent is missing

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Amides, C16-C18 (even numbered)

Molecular formula:

not available, UVCB

IUPAC Name:

Amides, C16-C18 (even numbered)

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Name of test material (as cited in study report): Crodamide SR (Stearamide), alternative name: Octadecanamide
- Molecular formula: C18H37NO
- Molecular weight: 283.496
- Physical state: Solid, white powder
- Analytical purity: 97 %
- Lot/batch No.: 984

Method

Target gene:

His operon

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Species / strain 2

Species / strain / cell type:

S. typhimurium TA 1538

Metabolic activation:

with and without

Metabolic activation system:

S9-mix prepared from Aroclor 1254 rats

Test concentrations with justification for top dose:

Dose range finding test: 5000, 500, 50, 5 µg/plate
Mutation tests: 5000, 1500, 500, 150, 50 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: Ethanol

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Remarks:

Ethanol

True negative controls:

no

Positive controls:

yes

Positive control substance:

9-aminoacridine

2-nitrofluorene

N-ethyl-N-nitro-N-nitrosoguanidine

other: 2-aminoanthracene

Details on test system and experimental conditions:

METHOD OF APPLICATION:
- In agar (plate incorporation)

DURATION
- Exposure duration: 3 days

NUMBER OF REPLICATIONS: 3, the procedures were repeated in a second mutation assay at a later date using the same dose levels

DETERMINATION OF CYTOTOXICITY
- Method: substantial reduction in revertant colony counts or by the absence of a complete background bacterial lawn

Colonies were counted using a Biotran Automatic Colony Counter, and the mean number of revertant colonies per treatment group assessed

Evaluation criteria:

- If treatment with a test material produces an increase in revertant colony numbers of at least twice the concurrent solvent controls, with some evidence of a positive dose-relationship, in two separate experiments, with any bacterial strain either in the presence or absence of S9-mix, it will be considered to show evidence of mutagenic activity in this test system.
- If treatment with a test material does not produce reproducible increases of at least 1.5 times the concurrent solvent controls, at any dose level with any bacterial strain, it will be considered to show no evidence of mutagenic activity in this test system

Statistics:

No statistical analysis performed

Results and discussion

Test results

Test results 1

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Remarks:

maximum guideline concentration of 5 mg/plate tested

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

True negative controls validity:

not examined

Positive controls validity:

valid

Test results 2

Key result

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Remarks:

maximum guideline concentration of 5 mg/plate tested

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

True negative controls validity:

not examined

Positive controls validity:

valid

Test results 3

Key result

Species / strain:

S. typhimurium TA 1538

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Remarks:

maximum guideline concentration of 5 mg/plate tested

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

True negative controls validity:

not examined

Positive controls validity:

valid

Test results 4

Key result

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Remarks:

maximum guideline concentration of 5 mg/plate tested

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

True negative controls validity:

not examined

Positive controls validity:

valid

Test results 5

Key result

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Remarks:

maximum guideline concentration of 5 mg/plate tested

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

True negative controls validity:

not examined

Positive controls validity:

valid

Additional information on results:

RANGE-FINDING/SCREENING STUDIES:
The revertant colony counts for Amides, C16-C18 (even numbered) obtained in the preliminary toxicity test revealed that Amides, C16-C18 (even numbered) was not toxic towards the tester strains. Therefore 5000 µg/plate was chosen as the top dose level in the mutation tests.

Any other information on results incl. tables

No substantial increases in revertant colony numbers of any of the tester strains were observed following treatment with Amides, C16-C18 (even numbered) at any dose level, either in the presence or absence of S9-mix. It is concluded that Amides, C16-C18 (even numbered) shows no evidence of mutagenic activity when tested in this bacterial system.

Applicant's summary and conclusion

Conclusions:

Interpretation of results:
negative