[No public or meaningful name is available]

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Bacterial Reverse Mutation assay:

The test substance was found to be non-mutagenic under the conditions of this test.

Link to relevant study records

Reference

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 21 October, 1997 to 20 November, 1997

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

JAPAN: Guidelines for Screening Mutagenicity Testing Of Chemicals

Version / remarks:

Kanpogyo No. 700, the Japanese Environment Agency, Yakuhatsu No. 1039, the Japanese Ministry of Health and Welfare and 61Kikyoku No. 1014, the Japanese Ministry of International Trade and Industry, 1986

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: JAPAN: Industrial Safety and Health Law

Version / remarks:

Notification No.77, 1988, the Japanese Ministry of Labour

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial forward mutation assay

Specific details on test material used for the study:

-Name of test material (as cited in study report): Dihydrofarnesol
-Substance type: colorless oil
-Analytical purity: >99% (subsequent information by sponsor)
-Impurites (identity and concentrations): no information
-Strage condition of test material: in a dark and cool place
-Stability: stable at room temperature

Target gene:

his operon (for S. typhimurium strains)
trp operon (for E.coli strain)

Species / strain / cell type:

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

Species / strain / cell type:

E. coli WP2 uvr A

Metabolic activation:

with and without

Metabolic activation system:

Cofactor supplemented post-mitochondrial fraction (S9 mix), prepared from the livers of rats treated with phenobarbitone and β-naphthoflavone

Test concentrations with justification for top dose:

Range-finding study 1 (for all tester strains with and without metabolic activation): 0.31, 1.22, 4.88, 19.5, 78.1, 313, 1250 and 5000 μg/plate
Range-finding study 2 (for TA1535, TA1537, TA98 and TA100 without metabolic activation): 0.076, 0.305, 1.22, 4.88 and 19.5 μg/plate
Main test (for TA1535, TA1537, TA98 and TA100 without metabolic activation): 0.61, 1.22, 2.44, 4.88, 9.77 and 19.5 µg/plate
Main test (for WP2uvrA with and without metabolic activation, TA1535 and TA98 with metabolic activation): 156, 313, 625, 1250, 2500 and 5000 µg/plate
Main test (for TA1537 with metabolic activation): 2.44, 4.88, 9.77, 19.5, 39.1 and 78.1 µg/plate
Main test (for TA100 with metabolic activation): 39.1, 78.1, 156, 313, 625 and 1250 µg/plate

Vehicle / solvent:

- Vehicle used: DMSO
- Justification for choice of solvent/vehicle: Based on the information from the sponsor that the test material was soluble at 5% and more in DMSO.

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Remarks:

Positive control substance: other: 2-aminoanthracene (2AA), 2-(2-Furyl)-3-(5-nitro-2-furyl)acrylamide (AF-2), 9-aminoacridin (9-AA) , sodium azide (NaN3)

Remarks:

+S9: 2AA (0.5 µg/plate, TA98; 1 µg/plate, TA100; 2 µg/plate, TA1535, TA1537; 10 µg/plate, WP2uvrA) −S9: AF-2 (0.01 µg/plate, TA100, WP2uvrA; 0.1 µg/plate, TA98); 9-AA (80 µg/plate, TA1537); NaN3 (0.5 µg/plate, TA1535)

Details on test system and experimental conditions:

METHOD OF APPLICATION: preincubation
DURATION
- Preincubation period: 20 min
- Exposure duration: 48 h
NUMBER OF REPLICATIONS: doubles each in two independent experiments
DETERMINATION OF CYTOTOXICITY
- Method: growth inhibition and test material precipitation

Evaluation criteria:

A test material is considered positive (mutagenic) in the test if:
a) It induces a number of revertant colonies, dose related, greater than two-times the number of revertants induced by the solvent control in any of the test strains, either with or without metabolic activation.
b) The positive response should be reproducible in at least two separated experiments.

Statistics:

Mean values was calculated. The statistical analysis was not used.

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Key result

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Key result

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Key result

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Key result

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Additional information on results:

PRECIPITATION
Precipitation on the plates was observed at 2500 and 5000 µg/plate with and without metabolic activation.

RANGE-FINDING/SCREENING STUDIES:
Growth inhibition by the test material was observed in S. typhimurium strains (TA1535, TA1537, TA98 and TA100) with and without metabolic activation. Therefore, as the highest dose level of the test material in the main test, the dose at which the growth inhibition was observed was selected for S. typhimurium strains (TA1535, TA1537, TA98 and TA100).

CONTROL SUBSTANCES:
All positive control substances gave increases in revertants, both with and without metabolic activation, within expected ranges, and solvent control plates gave counts of revertant colonies within the normal range.

Remarks on result:

other: All strains/cell types tested

Conclusions:

Interpretation of results (migrated information): negative

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)