Reaction mass of 1,2,3,4,5,6,7,8-octahydro-5,5-dimethylnaphthalene-2-carbaldehyde and 1,2,3,4,5,6,7,8-octahydro-8,8-dimethyl-2-naphthaldehyde

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

The test substance is not mutagenic.

Link to relevant study records

Reference

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

no Salmonella Typhimurium strain TA102 or E. Coli strain was used

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Specific details on test material used for the study:

- Description: Colourless liquid

Species / strain / cell type:

S. typhimurium, other: TA 1535, TA 1537, TA 1538, TA 98, TA 100

Metabolic activation:

with and without

Metabolic activation system:

Aroclor 1254 induced rat liver

Test concentrations with justification for top dose:

0, 3.09, 9.26, 27.78, 83.33, 250.00 µg/plate. Highest dose based on results preliminary test.

Vehicle / solvent:

DMSO

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

9-aminoacridine

2-nitrofluorene

sodium azide

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

DETERMINATION OF CYTOTOXICITY
- Method: reduction of background lawn

Evaluation criteria:

A positive response in the assay system is taken to be a two-fold or greater increase in the mean number of revertant colonies appearing in the test plates over and above the background spontaneous reversion rate observed with the vehicle, together with evidence of a dose response.

Key result

Species / strain:

S. typhimurium, other: TA 1535, TA 1537, TA 1538, TA 98, TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Additional information on results:

RANGE-FINDING/SCREENING STUDIES:
A preliminary test was carried out to assess the toxicity of the test substance for TA 98. Dose levels tested were 0, 3.78, 37.8, 378, 3780, and 37800 µg/plate. The results show that the test substance was toxic for the bacteria at dose levels of 378 µg/plate and higher, while no toxicity was observed at dose levels of 37.8 µg/plate and lower. At the highest dose levels used, the test substance precipitated in the plate.

ADDITIONAL INFORMATION ON CYTOTOXICITY:
At the two highest dose levels, the test substance was toxic for TA 1537, TA 1538, TA 98, and TA 100, both in the absence and in the presence of the S9-mix, as evidenced by a diminished growth of the bacterial background lawn. With TA 1535 slight toxicity was observed at the highest dose level used, only in the absence of the S9-mix.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

In the first bacterial reverse mutation assay, performed according to OECD Guideline 471 and following GLP, Salmonella typhimurium strains TA 1535, TA 1537, TA 98, and TA 100 and Escherichia coli strain WP2uvrA were exposed to the test material in DMSO (vehicle) with a pre-incubation method in the presence and absence of a metabolic activation system (S9 mix). Test concentrations used were without metabolic activation (µg/plate): 0, 0.610, 1.22, 2.44, 4.88, 9.77, 19.5, 39.1 (E. Coli only), 78.1 (E. Coli only) and with metabolic activation (µg/plate): 0, 2.44, 4.88, 9.77, 19.5, 39.1, 78.1, 156, (E. Coli only) 313 (E. Coli only). These concentrations are based on the results of a preliminary test. The results of the vehicle and positive controls show the validity of the test. It was concluded that the test substance did not increase the number of revertants in the presence and absence of S9 -mix.

In the second bacterial reverse mutation assay, performed similar to OECD Guideline 471 and following GLP, Salmonella typhimurium strains TA 1535, TA 1537, TA 1538, TA 98, and TA 100 were exposed to the test material in DMSO (vehicle) using the pre-incubation method. Test concentrations used were 0, 3.09, 9.26, 27.78, 83.33, and 250 µg/plate. These concentrations are based on the results of a preliminary test with Salmonella typhimurium strain TA 98. Strains were exposed in the presence and absence of a metabolic activation system (S9). The results of the vehicle and positive controls show the validity of the test. It was concluded that the test substance did not increase the number of revertants in the presence and absence of S9 -mix.

Justification for classification or non-classification

The test substance does not have to be classified for mutagenicity according to Regulation (EC) No 1272/2008.