2',4',5',7'-tetrabromo-4,5,6,7-tetrachloro-3',6'-dihydroxyspiro[isobenzofuran-1(3H),9'-[9H]xanthene]-3-one

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Ames test:

The test chemical did not induce mutation in the Salmonella typhimurium strains both in the presence and absence of S9 metabolic activation system and hence is not likely to be mutagenic under the conditions of this study.

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

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

Qualifier:

according to guideline

Guideline:

other: Refer below principle

Principles of method if other than guideline:

Salmonella/ mammalian-microsome test was performed to evaluate the mutagenic nature of the test compound as per the plate incorporation assay

GLP compliance:

not specified

Type of assay:

bacterial gene mutation assay

Target gene:

No data available

Species / strain / cell type:

S. typhimurium, other: TA98, TA1537, TA100, TA1535

Details on mammalian cell type (if applicable):

Not applicable

Additional strain / cell type characteristics:

not applicable

Cytokinesis block (if used):

No data

Metabolic activation:

with and without

Metabolic activation system:

The microsomal fraction (S9) was prepared from male Sprague-Dawley rats weighing approximately 200 g each.

Test concentrations with justification for top dose:

10-250 mg

Vehicle / solvent:

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

Untreated negative controls:

not specified

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

not specified

Positive controls:

not specified

Positive control substance:

not specified

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Preincubation period: No data available
- Exposure duration: 48 hrs
- Expression time (cells in growth medium): 48 hrs
- Selection time (if incubation with a selection agent): No data available
- Fixation time (start of exposure up to fixation or harvest of cells): No data available

SELECTION AGENT (mutation assays): No data available
SPINDLE INHIBITOR (cytogenetic assays): No data available
STAIN (for cytogenetic assays): No data available

NUMBER OF REPLICATIONS: No data available

NUMBER OF CELLS EVALUATED: No data available

DETERMINATION OF CYTOTOXICITY
- Method: mitotic index; cloning efficiency; relative total growth; other: No data available

OTHER EXAMINATIONS:
- Determination of polyploidy: No data available
- Determination of endoreplication: No data available
- Other: No data available

OTHER: No data available

Rationale for test conditions:

No data available

Evaluation criteria:

Materials which caused a 2-fold increase of revertants, as compared to the number of spontaneous revertants on the control plates, were denoted as mutagens. Those which reduced the number of revertants were considered inhibitory.

Statistics:

No data available

Species / strain:

S. typhimurium, other: TA98, TA1537, TA100, TA1535

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:

not specified

Additional information on results:

No data available

Conclusions:

The test chemical did not induce gene mutation in Salmonella typhimurium TA98, TA1537, TA100, TA1535 in the plate incorporation assay both in the presence and absence of S9 metabolic activation system and hence is negative for gene mutation in vitro.

Executive summary:

Salmonella/ mammalian-microsome test was performed to evaluate the mutagenic nature of the test chemical. The 2 ml of liquid top agar was cooled to 45°C and 0.1 ml of a broth culture of microorganism and test substance at dose level of 10 -250 mg and in volumes of ≤ 0.4 ml of DMSO was added prior to placing on minimal agar plates. After 48 h incubation at 37°C, the colonies which reverted to the prototroph were counted and compared to counts on the control plate (containing no test substance) to demonstrate mutagenicity or toxicity. Materials which caused a 2-fold increase of revertants, as compared to the number of spontaneous revertants on the control plates, were denoted as mutagens. Those which reduced the number of revertants were considered inhibitory. The test chemical did not induce gene mutation in Salmonella typhimurium TA98, TA1537, TA100, TA1535 in the plate incorporation assay both in the presence and absence of S9 metabolic activation system and hence is negative for gene mutation in vitro.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Gene mutation in vitro:

Data available for the test chemical was reviewed to determine the mutagenic nature of test chemical. The studies are as mentioned below:

Salmonella/ mammalian-microsome test was performed to evaluate the mutagenic nature of the test chemical. The 2 ml of liquid top agar was cooled to 45°C and 0.1 ml of a broth culture of microorganism and test substance at dose level of 10 -250 mg and in volumes of ≤ 0.4 ml of DMSO was added prior to placing on minimal agar plates. After 48 h incubation at 37°C, the colonies which reverted to the prototroph were counted and compared to counts on the control plate (containing no test substance) to demonstrate mutagenicity or toxicity. Materials which caused a 2-fold increase of revertants, as compared to the number of spontaneous revertants on the control plates, were denoted as mutagens. Those which reduced the number of revertants were considered inhibitory. The test chemical did not induce gene mutation in Salmonella typhimurium TA98, TA1537, TA100, TA1535 in the plate incorporation assay both in the presence and absence of S9 metabolic activation system and hence is negative for gene mutation in vitro.

In the similar study, Salmonella/ mammalian-microsome test (Spot test) was performed to evaluate the mutagenic nature of the test compound. The spot test was used to screen the test material for potential mutagenicity . The test material was placed in the center of the plate. The test compound was tested with and without the S9 mix. Inhibition of the bacterium was indicated by a clearing of the background lawn in a zone surrounding the test material. Mutagenicity was indicated by a clustering of revertant colonies directly around the test material or at the edge of the inhibitory zone. A known mutagen, Captan, was used as a reference mutagen. The test chemical did not induce mutation in Salmonella typhimurium TA98, TA1537, TA100, TA1535 in the spot test performed in the presence and absence of S9 metabolic activation system and hence is negative for gene mutation in vitro.

In another study Salmonella/mammalian microsome assay for test chemical using theSalmonella typhimurium strains TA1535, TA100, TA1537, TA1538, and TA98. The dye at dose levels of 0, 10, 50 or 100 µg/plate was dissolved in DMSO and up to 0.2 ml was introduced into 2.5 ml of the tempered top agar together with 0.1 ml Salmonella typhimurium broth suspension and 0.25 ml Aroclor 1254 induced rat liver S9. The mixtures was plated on 20 ml of Vogel-Bonner E bottom agar in the usual fashion and incubated for 3 days at 35°C. The test material failed to induce any mutation in the strain. However, slight toxicity was noted in the strains TA1537 (at 10 µg/plate with S9) and TA98 (at 10 and 100 µg/plate without S9). The test chemical did not induce gene mutation in Salmonella typhimurium strains TA1535, TA100, TA1537, TA1538 and TA98 in the presence and absence of S9 metabolic activation system and hence it is not likely to classify as a gene mutant in vitro.

Another study was performed as per the plate incorporation assay using Salmonella typhimurium strains TA1535, TA1537, TA1538, TA100 and TA98 both in the presence and absence of S9 metabolic activation system. The test chemical was dissolved in either water, dimethyl sulfoxide, and acetone at a dose level of 0, 33, 100, 333, 1000 and 3333 µg/plate by Plate-incorporation method. Concurrent positive controls were also incorporated in the study. The doses for the main study were based on the preliminary study conducted in which the viability of the bacterial cells on complete medium was measured at concentrations up to 10 mg/plate or to the limit of solubility. When solubility and toxicity were not limiting factors, the maximum concentration tested was 10 mg/plate. A response was considered positive if there was a dose-related increase in the number of revertants above spontaneous solvent controls, with a 2-fold increase for strains TA1535, TA1538, TA98 and TA100, and a 3-fold increase for TA1537. The test chemical failed to induce gene mutation in the bacterial strains TA1535, TA1537, TA1538, TA100 and TA98 in the presence and absence of S9 metabolic activation system and hence the test chemical is not likely to classify as a gene mutant in vitro.

Based on the data available, the target chemical does not exhibit gene mutation in vitro. Hence the test chemical is not likely to classify as a gene mutant as per the criteria mentioned in CLP regulation.

Justification for classification or non-classification

Based on the data available from the summarized studiesthe test chemical does not exhibit gene mutation in vitro. Hence the test chemical is not likely to classify as a gene mutant as per the criteria mentioned in CLP regulation.