o-phenylenediamine

Genetic toxicity: in vitro

Administrative data

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: Important aspects are in line with current OECD guidelines, but reliability is restricted due to missing approval of GLP compliance.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1983

Report date:

1983

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

not specified

Principles of method if other than guideline:

This report describes experiments performed according to the procedure of the Salmonella / mammalian-microsome-mutagenicity test described by Ames (1973 and 1975) to assess the mutagenic potential of the test substance in strains of Salmonella typhimurium and a strain of Escherichia coli described by Green (1976).

o-Phenylendiamin was tested for mutagenicity with the strains TA 100, TA 1535, TA 1537, TA 1538, TA 98 of Salmonella typhimurium and
Escherichia coli WP2uvrA.

The mutagenicity studies were conducted in the absence and in the presence of a metabolizing system derived from rat liver homogenate. A dose range of 5 different doses from 4 µg/plate to 2500 µg/plate was used.

GLP compliance:

no

Type of assay:

bacterial gene mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

o-phenylenediamine

EC Number:

202-430-6

EC Name:

o-phenylenediamine

Cas Number:

95-54-5

Molecular formula:

C6H8N2

IUPAC Name:

benzene-1,2-diamine

Details on test material:

- Name of test material (as cited in study report): o-Phenylendiamin (Code: Hoe 37197 OT AT201)

Method

Species / strain

Species / strain 1

Species / strain / cell type:

E. coli WP2 uvr A

Species / strain 2

Species / strain / cell type:

other: Salmonella typhimurium TA 100, TA 1535, TA 1537, TA 1538, TA 98

Metabolic activation:

with and without

Metabolic activation system:

Liver homogenate fraction (S9-mix) of Spague Dawley rats pretreated with Aroclor 1254.

Test concentrations with justification for top dose:

0, 4, 20, 100, 500, 2500 µg/plate

Vehicle / solvent:

aqua bidest (main test) or DMSO (range finding)

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: Sodium azide, 9-Aminoacridine, 2-Nitroflurorene, N-Methyl-N'-nitro-N-nitrosoguanidine (MNNG), Benzo[a]pyrene, 2-Aminoanthracene

Evaluation criteria:

negative: no dose dependent increase in the number of revertant colonies
positive: dose dependent increase in the number of revertant colonies

Statistics:

no data

Results and discussion

Test results

Test results 1

Species / strain:

other: Salmonella typhimurium TA 100, TA 1535, TA 1537, TA 1538, TA 98, E. coli WP2 uvr A

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

other: not cytotoxic for most of the bacterial strains at doses up to 2500µg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 2

Species / strain:

other: Salmonella typhimurium TA 1535, E. coli WP2 uvr A

Metabolic activation:

with

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

other: not cytotoxic for most of the bacterial strains at doses up to 2500µg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 3

Species / strain:

other: Salmonella typhimurium TA 100, TA 1537, TA 1538, TA 98

Metabolic activation:

with

Genotoxicity:

positive

Cytotoxicity / choice of top concentrations:

other: not cytotoxic for most of the bacterial strains at doses up to 2500µg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:

Summarizing, it can be stated that o-Phenylendiamin is mutagenic in these bacterial test systems in the presence of exogenous metabolic activation.

Executive summary:

o-Phenylendiamin was tested for mutagenicity with the strains TA 100, TA 1535, TA 1537, TA 1538, TA 98 of Salmonella typhimurium and Escherichia coli WP2uvrA.

The mutagenicity studies were conducted in the absence and in the presence of a metabolizing system derived from rat liver homogenate. A dose range of 5 different doses from 4 µg/plate to 2500 µg/plate was used.

Control plates without mutagen showed that the number of spontaneous revertant colonies was similar to that described in the literature. All positive control compounds gave the expected increase in the number of revertant colonies.

Toxicity: The test compound proved to be not toxic for most of the bacterial strains at doses up to 2500 µg/plate. 2500 µg/plate was chosen as top dose level for the mutagenicity study.

Mutagenicity: In the absence of the metabolic activation system the test compound did not show a dose dependent influence in the number of revertants in any of the bacterial strains. In the presence of metabolic activation, treatment of the cells wtih o-Phenylendiamin resulted in relevant increases in the number of revertant colonies with the Salmonella strains TA 10O, TA 1537, TA 1538 and TA 98.

Summarizing, it can be stated that o-Phenylendiamin is mutagenic in these bacterial test systems in the presence of exogenous metabolic activation.