Reaction mass of (3R)-3-[(1R)-1-ethoxyethoxy]-3-methylpent-1-en-4-yne and (3R)-3-[(1S)-1-ethoxyethoxy]-3-methylpent-1-en-4-yne and (3S)-3-[(1R)-1-ethoxyethoxy]-3-methylpent-1-en-4-yne and (3S)-3-[(1S)-1-ethoxyethoxy]-3-methylpent-1-en-4-yne

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

The test substance is not a mutagenic substance in a bacterial reverse mutation test (OECD 471, GLP) in the absence and the presence of metabolic activation.

Link to relevant study records

Reference

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP compliant guideline study, available as unpublished report, restriction in design (no E.coli WP2 or S.typhimurium TA 102 used and only one positive control used to test efficacy of the S9-mix), but adequate for assessment

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

, no E.coli WP2 or S.typhimurium TA 102 used and only one positive control used to test efficacy of the S9-mix

Qualifier:

according to guideline

Guideline:

EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)

Version / remarks:

EEC Directive 84/449, B14. Mutageniticy (Salmonella typhimurium - reverse mutation assay)

Deviations:

yes

Remarks:

, no E.coli WP2 or S.typhimurium TA 102 used and only one positive control used to test efficacy of the S9-mix

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Target gene:

His-locus

Species / strain / cell type:

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

Metabolic activation:

with and without

Metabolic activation system:

Aroclor-1254 induced rat liver S-9 mix

Test concentrations with justification for top dose:

1st and 2nd experiment: 0, 100, 500, 2500, 5000 µg/plate
3rd experiment: 500, 1000, 1500, 2000 µg/plate

Vehicle / solvent:

Vehicle used: DMSO

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Remarks:

2.5 µg/plate

Positive control substance:

other: 2-aminoanthracene

Remarks:

All strains tested with metabollic activation

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Remarks:

5 µg/plate

Positive control substance:

other: N-methyl-N'-nitro-N-nitrosoguanidine

Remarks:

TA 100, TA 1535; without metabolic activation

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Remarks:

10 µg/plate

Positive control substance:

other: 4-nitro-o-phenylendiamine

Remarks:

TA 98; without metabolic activation

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Remarks:

100 µg/plate

Positive control substance:

9-aminoacridine

Remarks:

TA 1537; without metabolic activation

Details on test system and experimental conditions:

--> 1st EXPERIMENT

METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Exposure duration: 48 h

NUMBER OF REPLICATIONS:
- 3 test plates per dose or per control

DETERMINATION OF CYTOTOXICITY
- Method: Reduces his- background growth, decrease in the number of his+ revertants


--> 2nd and 3rd EXPERIMENT

METHOD OF APPLICATION: preincubation

DURATION
- Preincubation period: 20 min
- Exposure duration: 48 h

NUMBER OF REPLICATIONS:
- 3 test plates per dose or per control

DETERMINATION OF CYTOTOXICITY
- Method: Reduces his- background growth, decrease in the number of his+ revertants

Evaluation criteria:

In general, a substance to be characterized as positve in the Ames test has to fulfill the following requirements:
- doubling of the spontaneous mutation rate (control)
- dose-response relationship
- reproducibility of the results

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:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

ADDITIONAL INFORMATION ON CYTOTOXICITY:
A bacteriotoxic effect (reduced his- background growth, decrease in the number of his+ revertants) was observed in the standard plate test at doses ≥ 2500 µg/plate. In the preincubation test bacteriotoxicity was observed from about 1000 µg - 1500 µg onward.

TEST-SPECIFIC CONFOUNDING FACTORS
No test substance precipitation was found.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Conclusions:

Interpretation of results (migrated information):
negative

Under the experimental conditions, it is concluded that the test substance is not a mutagenic substance in the bacterial reverse mutation test in the absence and the presence of metabolic activation.

Executive summary:

The substance was tested for its mutagenic potential, in an OECD 471 guideline study (compliant with GLP), based on the ability to induce back mutation in selected loci in several strains of Salmonella typhimurium (TA 1535, TA 100, TA 1537, TA 98) in the Ames test. Bacteria were exposed to 20 - 5000 μg/plate in a standard plate test and a preincubation test both with and without metabolic activation (Aroclor-induced rat liver S9 mix). No precipitation of the test substance was found. A bacteriotoxic effect was observed at doses ≥ 2500 µg in the standard plate test and from about 1000 - 1500 µg/plate onward in the preincubation assay. An increase in the number of his+ revertants was not observed both in the standard plate test and in the preincubation test either without S-9 mix or after the addition of this metabolizing system. The test substance is not mutagenic in the Ames test under these experimental conditions.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Additional information

Additional information from genetic toxicity in vitro:

The substance was tested for its mutagenic potential, in an OECD 471 guideline study (compliant with GLP), based on the ability to induce back mutation in selected loci in several strains of Salmonella typhimurium (TA 1535, TA 100, TA 1537, TA 98) in the Ames test (BASF 1994). Bacteria were exposed to 20 - 5000 μg/plate in a standard plate test and a preincubation test both with and without metabolic activation (Aroclor-induced rat liver S9 mix). No precipitation of the test substance was found. A bacteriotoxic effect was observed at doses ≥ 2500 µg in the standard plate test and from about 1000 - 1500 µg/plate onward in the preincubation assay. An increase in the number of his+ revertants was not observed both in the standard plate test and in the preincubation test either without S-9 mix or after the addition of this metabolizing system. The test substance is not mutagenic in the Ames test under these experimental conditions.

Justification for selection of genetic toxicity endpoint
One genetic toxicity in vitro study is available. This study is adequate for covering this endpoint.

Justification for classification or non-classification

The test substance is non-mutagenic in a bacterial reverse mutation assay. Therefore classification in accordance with EU Directive 67/548 (DSD) and EU Classification, Labeling and Packaging of Substances and Mixtures (CLP) Regulation No. 1272/2008 is not warranted.