p-tolualdehyde

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

The test material was considered to be non-mutagenic in the Ames test performed.

Link to relevant study records

Reference

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Qualifier:

according to guideline

Guideline:

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

Qualifier:

according to guideline

Guideline:

JAPAN: Guidelines for Screening Mutagenicity Testing Of Chemicals

Version / remarks:

including METI, MHLW and MAFF

Qualifier:

according to guideline

Guideline:

other: EPA (TSCA) OPPTS harmonised guidelines

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Specific details on test material used for the study:

- Identification: PTAL (p-Methylbenzaldehyde)
- Description: clear colourless liquid
- Purity: 99.71%
- Batch No.: PTAL-5M12
- Storage conditions: room temperature in the dark under nitrogen

Species / strain / cell type:

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

Additional strain / cell type characteristics:

not applicable

Species / strain / cell type:

E. coli WP2 uvr A

Additional strain / cell type characteristics:

not applicable

Metabolic activation:

with and without

Metabolic activation system:

phenobarbitone/ß-naphthoflavone induced rat liver S9-mix

Test concentrations with justification for top dose:

- Preliminary toxicity test: 0.15, 0.5, 1.5, 5, 15, 50, 150, 500, 1500, 1500, 5000 µg/plate
- Experiment 1 & 2: 50, 150, 500, 1500, 5000 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: The test material was immiscible in distilled water but was fully miscible in dimethyl sulphoxide

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

9-aminoacridine

N-ethyl-N-nitro-N-nitrosoguanidine

benzo(a)pyrene

other: 4-Ntiroquiloline-1-oxide (4NQO), 2-Aminoanthracene (2AA)

Details on test system and experimental conditions:

STRAINS USED
- Preliminary Toxicity Test: TA 100, WP2 uvrA
- Experiment 1 & 2: TA 98, TA 100, TA 1535, TA 1537, WP2 uvrA

METHOD OF APPLICATION: in agar (plate incorporation)
DURATION : Exposure duration: 48 hours
NUMBER OF REPLICATIONS: 3
DETERMINATION OF CYTOTOXICITY: growth of the bacterial background lawn

Evaluation criteria:

The test material may be considered positive in this test system if the following criteria are met:
The test material should have induced a reproducible, dose-related and statistically (Dunnett’s method of linear regression) significant increase in the revertant count in at least one strain of bacteria.

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

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

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

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

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

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

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

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Species / strain:

E. coli WP2 uvr A

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:

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: no test material precipitate was observed on the plates at any of the doses tested in either the presence or absence of S9-mix

Conclusions:

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

Executive summary:

In a GLP compliant study, according to OECD guideline 471, Salmonella typhimurium strains TA 1535, TA 1537, TA 98, TA 100 and Escherichia coli strain WP2uvrA- were treated with the test material using the Ames plate incorpation method at five dose levels (50, 150, 500, 1500, 5000 µg/plate), in triplicate, both with and without the addition of phenobarbitone/ß-naphthoflavone induced rat liver S9-mix. The dose levels were determined in a preliminary toxicity assay. The vehicle (DMSO) 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 frequency of revertant colonies, both with and without metabolic activation. The test material caused no visible reduction in the growth of the bacterial background lawn at any dose level. No test material precipitate was observed at any of the doses. No significant increases in the frequency of revertant colonies were recorded for any of the bacterial strains, with any dose with or without metabolic activation. The test material was considered to be non-mutagenic under the conditions of this test.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

In a GLP compliant study, according to OECD guideline 471, Salmonella typhimurium strains TA 1535, TA 1537, TA 98, TA 100 and Escherichia coli strain WP2uvrA- were treated with the test material using the Ames plate incorpation method at five dose levels (50, 150, 500, 1500, 5000 µg/plate), in triplicate, both with and without the addition of phenobarbitone/ß-naphthoflavone induced rat liver S9-mix. The dose levels were determined in a preliminary toxicity assay. The vehicle (DMSO) 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 frequency of revertant colonies, both with and without metabolic activation. The test material caused no visible reduction in the growth of the bacterial background lawn at any dose level. No test material precipitate was observed at any of the doses. No significant increases in the frequency of revertant colonies were recorded for any of the bacterial strains, with any dose with or without metabolic activation. The test material was considered to be non-mutagenic under the conditions of this test.

Justification for classification or non-classification

Based on the available information classification for genetic toxicity is not warranted in accordance with Directive 67/548/EEC and in accordance with EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008.