4-nitro-o-toluidine

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Data is from peer reviewed publication

Data source

Reference

Reference Type:

publication

Title:

Studies on the oxidation products from 2,4-diaminotoluene by hydrogen peroxide and their mutagenicities. II

Author:

Tetsushi Watanabe, Mayumi Ono, Teruhisa Hirayama and Shozo Fukui

Year:

1989

Bibliographic source:

Mutation Research, 225 (1989) 15-19

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Principles of method if other than guideline:

Bacterial gene mutation assay was performed to determine the mutagenic nature of p-Nitro-o-toludine

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

2-methyl-4-nitroaniline

Cas Number:

99-52-9

Molecular formula:

C7H8N2O2

IUPAC Name:

2-methyl-4-nitroaniline

Details on test material:

- Name of test material: 4-Nitro-o-toludine
- Molecular formula: C7H8N2O2
- Molecular weight: 152.152 g/mol
- Substance type: Organic

Specific details on test material used for the study:

- Name of test material: p-Nitro-o-toludine
- IUPAC name: 2-methyl-4-nitroaniline
- Molecular formula: C7H8N2O2
- Molecular weight: 152.152 g/mol
- Substance type: Organic
- Purity: No data available
- Impurities (identity and concentrations): No data available

Method

Target gene:

Histidine

Species / strain

Species / strain / cell type:

S. typhimurium TA 98

Details on mammalian cell type (if applicable):

Not applicable

Additional strain / cell type characteristics:

not specified

Cytokinesis block (if used):

No data

Metabolic activation:

with and without

Metabolic activation system:

The postmitochondrial fraction (S9) was prepared from the liver of male Sprague-Dawley rats induced with PCB

Test concentrations with justification for top dose:

0 or 1 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: The chemical was soluble in DMSO

Controls

Untreated negative controls:

not specified

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

2-acetylaminofluorene

4-nitroquinoline-N-oxide

Details on test system and experimental conditions:

METHOD OF APPLICATION: in suspension
- Cell density at seeding (if applicable): No data

DURATION
- Preincubation period: No data
- Exposure duration: No data
- Expression time (cells in growth medium): No data
- Selection time (if incubation with a selection agent): No data
- Fixation time (start of exposure up to fixation or harvest of cells): No data

SELECTION AGENT (mutation assays): No data

SPINDLE INHIBITOR (cytogenetic assays): No data

STAIN (for cytogenetic assays): No data

NUMBER OF REPLICATIONS: Triplicate

METHODS OF SLIDE PREPARATION AND STAINING TECHNIQUE USED: No data

NUMBER OF CELLS EVALUATED: No data

NUMBER OF METAPHASE SPREADS ANALYSED PER DOSE (if in vitro cytogenicity study in mammalian cells): No data

CRITERIA FOR MICRONUCLEUS IDENTIFICATION: No data

DETERMINATION OF CYTOTOXICITY
- Method: mitotic index; cloning efficiency; relative total growth; other: No data
- Any supplementary information relevant to cytotoxicity: No data

OTHER EXAMINATIONS:
- Determination of polyploidy: No data
- Determination of endoreplication: No data
- Methods, such as kinetochore antibody binding, to characterize whether micronuclei contain whole or fragmented chromosomes (if applicable): No data

- OTHER: No data

Rationale for test conditions:

No data

Evaluation criteria:

The plates were observed for a dose dependent increase in the number of revertants/plate

Statistics:

No data

Results and discussion

Test results

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

Positive controls validity:

valid

Additional information on results:

No data

Any other information on results incl. tables

Table: Mutagenicity of p-Nitro-o-toluidine in S. typhimurium strain TA98

Sample	Dose (µg/plate	His^+revertants/plate
		Without	With
p-Nitro-o-toluidine	1	28	39
DMSO		14	28
4NQO	0.5	111
AAF	5		540

Applicant's summary and conclusion

Conclusions:

p-Nitro-o-toludine did not induce gene mutation in Salmonella typhimurium strain TA98 in the presence and absence of S9 metabolic activation system and hence the chemical is not likely to classify as a gene mutant in vitro.

Executive summary:

Bacterial gene mutation assay was performed to determine the mutagenic nature of p-Nitro-o-toludine. The assay was performed using Salmonella typhimurium strain TA98 with and without S9 metabolic activation system. Suspension assay was performed with the test chemical dissolved in DMSO at dose level of 0 or 1 µg/plate. The plates were observed for a dose dependent increase in the number of revertants/plate. p-Nitro-o-toludine did not induce gene mutation in Salmonella typhimurium strain TA98 in the presence and absence of S9 metabolic activation system and hence the chemical is not likely to classify as a gene mutant in vitro.