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Toxicological information

Genetic toxicity: in vitro

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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: Test method equivalent or similar to OECD Guideline 471.

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
1982

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
GLP compliance:
not specified
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): sodium dimethyldithiocarbamate (DDC)

Method

Species / strain
Species / strain:
other: S. typhimurium TA 1535, TA 1537, TA1538, TA 98, TA 100 and E. coli WP2 hcr.
Metabolic activation:
with and without
Metabolic activation system:
S9 mix.
Test concentrations with justification for top dose:
Up to 5000 µg/plate.
Vehicle:
- Vehicle(s)/solvent(s) used: DMSO.
Controls
Negative controls:
not specified
Solvent controls:
not specified
Positive controls:
yes
Details on test system and conditions:
METHOD OF APPLICATION: in agar (plate incorporation).
To 2 ml of the top agar were added 0.1 ml of one of bacterial suspensions in phosphate buffer (1/15 M), 0.1 ml of the solution of the test item and, when required, 0.5 ml of the S9 mix (0.3 ml of S9 fraction/ml S9 mix). The contents were poured onto the surface of a minimal agar plate with modified Vogel-Bonner E medium. Plates were incubated at 37 ºC for 2 days, after which the number of revertant colonies on each plate was counted.

Results and discussion

Test resultsopen allclose all
Species / strain:
other: S. typhimurium TA 1537, TA 1538 and TA98.
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity:
not specified
Vehicle controls valid:
not specified
Negative controls valid:
not specified
Positive controls valid:
yes
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.
Species / strain:
other: S. typhimurium TA 1535 and E.coli WP2 hcr.
Metabolic activation:
with and without
Genotoxicity:
positive
Remarks:
(weakly positive)
Cytotoxicity:
not specified
Vehicle controls valid:
not specified
Negative controls valid:
not specified
Positive controls valid:
yes
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.
Species / strain:
S. typhimurium TA 100
Metabolic activation:
with and without
Genotoxicity:
positive
Cytotoxicity:
not specified
Vehicle controls valid:
not specified
Negative controls valid:
not specified
Positive controls valid:
yes
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.
Additional information on results:
The test item was positive in the base-change-type strains (E.coli WP2 hcr and Salmonella typhimurium TA1535 and TA100), but negative in the frameshift-type strains (TA 1537, TA 1538 and TA 98). The response in S. typhimurium TA 1535 and E.coli WP2 hcr was defined to be weakly positive as the number of revertants did not reach the criteria for a positive result but showed a dose-resposne relationship.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
positive

The test item was found to be positive in the base-change-type strains (E.coli WP2 hcr and Salmonella typhimurium TA1535 and TA100). Sodium dimethyldithiocarbamate is considered to be genotoxic in vitro.
Executive summary:

Sodium dimethyldithiocarbamate was tested for mutagenicity in a bacterial reversion-assay system with 5 strains (TA 100, TA 98, TA 1535, TA 1537 and TA 1538) of Salmonella typhimurium and a strain (WP2 hcr) of Escherichia coli, following a method equivalent or similar to the OECD Guideline 471. The experiment was carried out in the presence and the absence of metabolic activation (S9 mix). The test item was dissolved in DMSO and was tested at concentrations up to 5000 µg/plate. The test item was found to be positive in the base-change-type strains (E.coli WP2 hcr and Salmonella typhimurium TA1535 and TA100), but negative in the frameshift-type strains (TA 1537, TA 1538 and TA 98). From the results of the present study, the test substance is considered to be genotoxic in vitro.