PIGMENTADDITIV RL

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: according to guideline (OECD TG 471), and to GLP; but using a different set of tester strains

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

1989

Report date:

1989

Reference 2

Reference Type:

other: 1st Amendment to report No 89.1482

Title:

Unnamed

Year:

1992

Report date:

1992

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

; according to OECD 471 but different set of tester strains used

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Reference

Name:

Unnamed

Method

Species / strain

Species / strain 1

Species / strain / cell type:

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

Species / strain 2

Species / strain / cell type:

S. typhimurium TA 1538

Metabolic activation:

with and without

Metabolic activation system:

S9 liver microsomal fraction from Aroclor 1254 induced male Sprague Dawley rats

Test concentrations with justification for top dose:

Experiment 1: 0, 4, 20, 100, 500, 2500 and 10000 µg/plate
Experiment 2: 0, 4, 20, 100, 500, 2500 and 5000 µg/plate

Vehicle / solvent:

- DMSO (test material)
- vehicle used for positive controls not stated

Controls

Controls 1

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: sodium azide (TA 100, TA 1535), 9-aminoacridine (TA 1537), 2-nitrofluorene (TA 98, TA 1538)

Remarks:

without metabolic acivation

Controls 2

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: benzo[a]pyrene (all strains), 2-aminoanthracene (all strains)

Remarks:

with metabolic activation

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Preincubation period:
- Exposure duration:48-72 h
- Fixation time (start of exposure up to fixation or harvest of cells): 48-72 h

NUMBER OF REPLICATIONS: two independent experiments were performed in triplicate

DETERMINATION OF CYTOTOXICITY
- Method: microscopic inspection of bacterial lawn; reduced rate of spontaneously occuring colonies as well as visible thinning of the bacterial lawn were used as indicator for toxicity

Evaluation criteria:

not documented

Statistics:

not performed

Results and discussion

Test results

Test results 1

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:

no cytotoxicity, but tested up to precipitating concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 1538

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Additional information on results:

The test item precipitated at concentrations >/= 500 µg/plate.
In the first experiment a slight but not reproducible increase in the strain TA 1538 was observed in the two highest dose groups (mean values: 13, 12, 16, 18, 18, 27, 26 colonies per plate at 0, 4, 20, 100, 500, 2500, and 10000 µg/plate, respectively).

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

Under the conditions of this study the test substance was not mutagenic in bacteria in concentrations up to 10000 µg/plate with and without metabolic activation.

Executive summary:

The mutagenicity of the test item was examined in the bacterial strains TA 100, TA 1535, TA 1537, TA 1538, TA 98 of Salmonella typhimurium in a study according to OECD guideline 471 and GLP (but using a different set of tester strains). The mutagenicity studies were conducted in two independent experiments in the absence and in the presence of a metabolizing system derived from S9 liver homogenate of Aroclor 1254-induced male Sprague-Dawley rats. Test concentrations were 0, 4, 20, 100, 500, 2500 and 10000/5000 (experiment 1/experiment 2) µg/plate. Visible precipitation of the test compound on the plates has been observed at 500 µg/plate and above. Control plates with solvent showed that the number of spontaneous revertant colonies was similar to that described in the literature. The test compound proved to be not toxic to the bacterial strains. In the absence or presence of the metabolic activation system the test compound did not cause a significant or a dose dependent increase in the number of revertants in any of the bacterial strains. All the positive control compounds gave the expected increase in the number of revertant colonies, indicating the sensitivity of the test system and the appropriate activity of the S9 mix. It can be stated that the test item is not mutagenic in these bacterial test systems either with or without exogenous metabolic activation at the dose levels investigated.