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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
4 June 1981 - 1 July 1981
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1981
Report date:
1981

Materials and methods

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

Test material

Constituent 1
Chemical structure
Reference substance name:
1,3-dihydro-5-methoxy-2H-benzimidazole-2-thione
EC Number:
253-326-2
EC Name:
1,3-dihydro-5-methoxy-2H-benzimidazole-2-thione
Cas Number:
37052-78-1
Molecular formula:
C8H8N2OS
IUPAC Name:
5-methoxy-1,3-dihydro-2H-benzimidazole-2-thione
Specific details on test material used for the study:
Tan-grey powder

Method

Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Species / strain / cell type:
S. typhimurium TA 1538
Metabolic activation:
with and without
Metabolic activation system:
Liver S9, exogenous metabolic activation system of mammalian microsomal enzymes derived from Aroclor-induced rat (male Sprague-Dawley rats) liver.
Test concentrations with justification for top dose:
1,0 µg to 5000 µg per plate.
A preliminary toxicity study was conducted with doses 1.22 µg to 10,000.00 µg per plate and the bacteria (TA-100) exhibited aproximately 92% toxicity at 5000 µg.
Vehicle / solvent:
Solvent: DMSO
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
Positive controls:
yes
Positive control substance:
9-aminoacridine
2-nitrofluorene
sodium azide

Results and discussion

Test results
Species / strain:
other: as listed above
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
not specified
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid

Applicant's summary and conclusion

Conclusions:
The test material did not exhibit genetic activity in any of the assays conducted in this evaluation and was considered not mutagenic under these test conditions.