3-phenylbutyraldehyde

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Genetic Toxicity (in-vitro, OECD471): negative

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

Study period:

April - September 2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study in compliance with guidelines

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Species / strain / cell type:

other: S. typhimurium TA1535, TA1537, TA98, TA100 and E. coli WP2uvrA

Details on mammalian cell type (if applicable):

not applicable

Additional strain / cell type characteristics:

not applicable

Metabolic activation:

with and without

Metabolic activation system:

S9-Mix from rat liver

Test concentrations with justification for top dose:

Preliminary Toxicity Test: from 0, 0.15, 0.5, 1.5, 5, 15, 50, 150, 500, 1500 and 5000 µg/plate with or without metabolic activation system.

Mutation Test — Experiment 1 (Range-finding Test): from 15, 50, 150, 500, 1500 and 5000 µg/plate with or without metabolic activation system.

Mutation Test — Experiment 2 (Main Test): 15, 50, 150, 500, 1500, or 5000 µg/plate for all strains with or without metabolic activation system, except for TA100 (-S9): 150 500, 1000, 1500, 3000, or 5000 µg/plate

Vehicle / solvent:

- Vehicle/solvent used: dimethyl sulfoxide (DMSO)
- Justification for choice of solvent/vehicle: The test material was immiscible in sterile distilled water at 50 mg/mL but was fully miscible in DMSO at the same concentration in solubility checks.

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

other: N-ethyl-N’-nitro-N-nitrosoguanidine (ENNG), 9-Aminoacridine (9AA), 4-Nitroquinoline-1-oxide (4NQO), 2-Aminoanthracene (2AA), Benzo(a)pyrene (BP)

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)

TEST CONDITIONS (Composition)
- Bacterial suspension: 0.1 ml
- Test substance solution: 0.1 ml
- Na-phosphate buffer: 0.5 ml
- S9-mix (in case of metabolic activation method): 0.5 ml
- Top agar solution: 2.0 ml

TEST CONDITIONS (Incubation)
- Temperature: 37°C
- Time: 48 hrs

Evaluation criteria:

Count method: Colony counter
Correction method: Area and miscount correction
Evaluation criteria: Positive results are determined by criteria such as a dose-related increase in revertant frequency over the dose range tested and/or a reproducible increase at one or more concentrations in at least one bacterial strain with or without metabolic activation. Biological relevance of the results will be considered first, statistical methods, as recommended by the UKEMS can also be used as an aid to evaluation, however, statistical significance will not be the only determining factor for a positive response.

Statistics:

Statistical methods, as recommended by the UKEMS are used as an aid to evaluation.

Species / strain:

other: S. typhimurium TA1535, TA1537, TA98,TA100 and E. coli WP2uvrA

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

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

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

In the preliminary test, the test substance was toxic to the strains TA100 and WP2uvrA at 5000 µg/plate.

The vehicle control plates gave counts of revertant colonies within the normal range. All of the positive control chemicals used in the test induced marked increases in the frequency of revertant colonies, both with or without metabolic activation. Thus, the sensitivity of the assay and the efficacy of the S9-mix were validated.

The test material caused a visible reduction in the growth of the bacterial background lawns of all of the tester strains in both the absence and presence of S9, initially from 1500 µg/plate. The test material was, therefore, tested up to the maximum recommended dose level of 5000 µg/plate. No test material precipitate was observed on the plates at any of the doses tested in either the presence or absence of S 9-mix.

No toxicologically significant increases in the frequency of revertant colonies were recorded for any of the bacterial strains, with any dose of the test material, either with or without metabolic activation. Small but statistically significant increases in revertant colony frequency were observed for bacterial strain TA100 (absence of S9) between 50 and 1500 µg/plate in the range-finding test and at 150 µg/plate in the main test. These responses were considered not to be toxicologically significant as they were non-reproducible, the maximum fold increase was only 1.7 times the concurrent vehicle control value and all of the revertant counts were within the acceptable in-house historical range for the bacterial strain.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Conclusions:

Interpretation of results (migrated information):
negative under CLP REGULATION (EC) No 1272/2008

The test material was considered to be non-mutagenic under the conditions of the test.

Executive summary:

A GLP-compliant  in vitro  bacterial reverse mutation (Ames) assay was conducted to evaluate the potential for mutagenicity of the substance. The assay was conducted according to the OECD Testing Guideline No. 471 and the EU method B.13/14.  Salmonella typhimurium  strains TA1535, TA 1537, TA98 and TA100, and  Escherischia coli  strain WP2uvrA  were tested at concentrations up to 5000 µg/plate using the plate incorporation method, with the test concentrations having been determined following a preliminary toxicity test. Vehicle controls yielded colony counts within the expected normal range. Positive controls induced the expected increases in numbers of revertant colonies. These data confirmed the validity of the assay. The substance caused toxicity starting at 1500 µg/plate in the presence and absence of rat liver S9 and was thus tested at concentrations up to 5000 µg/plate. No precipitate was seen at any test concentration. There were no toxicologically significant increases in the frequency of revertant bacterial colonies for any of the test strains at any dose level, either in the presence or absence of S9. All of the revertant counts were within the acceptable historical range for the facility.

Based on these results, the substance was considered to be non-mutagenic under the conditions of the assay.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Additional information

Additional information from genetic toxicity in vitro:

A GLP-compliant  in vitro  bacterial reverse mutation (Ames) assay was conducted to evaluate the potential for mutagenicity of the substance in  S. typhimurium  strains TA1535, TA1537, TA98, TA100 and  E. coli  strain WP2uvrA  (Safepharm Laboratories Limited, 2007). The assay was conducted according to the OECD Testing Guideline No. 471 and the EU method B.13/14. The test was conducted at concentrations up to 5000 ug/plate using the plate incorporation method and included appropriate positive controls. There were no toxicologically significant increases in the frequency of revertant bacterial colonies for any of the test strains at any dose level, either in the presence or absence of S9. It was concluded that the substance is non-mutagenic under the conditions of the assay.

Justification for selection of genetic toxicity endpoint
Klimisch 1 study according to guideline study

Justification for classification or non-classification

Genetic Toxicity: the substance is non-mutagenic under the conditions of the available in vitro test. As a result, the substance does not meet the criteria for classification according to Regulation (EC) No 1272/2008, Annex I section 3.5.