Registration Dossier

Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Remarks:
Screening assay
Adequacy of study:
weight of evidence
Study period:
1990
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
test procedure in accordance with national standard methods with acceptable restrictions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1990
Report Date:
1990

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
GLP compliance:
no
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Details on test material:
CI Disperse Blue 284

Method

Species / strain
Species / strain / cell type:
S. typhimurium TA 98
Additional strain / cell type characteristics:
not applicable
Metabolic activation:
with and without
Metabolic activation system:
Aroclor-induced rat liver S9
Test concentrations with justification for top dose:
up to 1000 µg/plate
the substance is toxic at concentrations of 1000 µg/plate and above
Vehicle / solvent:
DMSO
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
Remarks:
Dimethylsulphoxide (DMSO)
True negative controls:
no
Positive controls:
yes
Positive control substance:
not specified

Results and discussion

Test results
Species / strain:
S. typhimurium TA 98
Metabolic activation:
with and without
Genotoxicity:
positive
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid

Applicant's summary and conclusion

Conclusions:
Under the conditions of this assay, the test substance gave a positive response with S. typhimurium strain TA98 in the presence and absence of an auxiliary metabolising system (S9).
Executive summary:

The mutagenic activity of Disperse Blue 284 (82.4%purity),was investigated in a screening assay in the plate incorporation test using the Salmonella typhimurium strain TA 98. The test article was tested at the concentrations up to 1000 µg/plate up to 1000 µg/plate. The test substance was toxic at concentrations of 1000 µg/plate and above.

Reproducible, dose-dependent increases in revertant colony numbers were obtained with and without S9 mix. In conclusion, it can be stated that during the described mutagenicity test and under the experimental conditions reported, the test article induced gene mutations by frameshifts in the genome in the tested strain. As the screening test was positive, no further experiment was conducted.