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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:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
The publication is a summary of several mutagenicity studies performed on methylhydrazine. The summarized report has been reviewed by the Information Office (OI) and is releasable to the National Technical Information Service (NTIS). Some data are absent (GLP statement, data on the test item(batch number, expiry date...)).

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1976
Report Date:
1076

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:
other: bacterial reverse mutation assay (Salmonella typhimurium and Escherichia coli)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): MH
- Substance type: monoconstituent
- Physical state: clear liquid

Method

Target gene:
histidine
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, other: G-46
Species / strain / cell type:
S. typhimurium TA 1538
Species / strain / cell type:
E. coli WP2 uvr A
Species / strain / cell type:
Saccharomyces cerevisiae
Metabolic activation:
with and without
Metabolic activation system:
mouse hepatic microsomes
Test concentrations with justification for top dose:
In agar assay without activation:
0.0001, 0.001, 0.01, 1 and 5 µL/plate
In agar assay with activation:
0.01, 0.1, 1 and 5 µL/plate
Suspension assay with activation:
1 and 5 µL/mL
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: DMSO
Controls
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: direct acting mutagens were employed in non activation assays, mutagens requiring microsomal activation were used in activation assays
Remarks:
Dimethylnitrosamine was used as the positive control compound in the suspension assay
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation) + additional assay with S. Typhimurium TA-1535 in suspension

DURATION:
- Exposure duration: 48 to 72 hours for plate incorporation assays, 1 hour for suspension assay

Results and discussion

Test resultsopen allclose all
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:
cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Species / strain:
S. typhimurium, other: G-46
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 1538
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Species / strain:
E. coli WP2 uvr A
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Species / strain:
Saccharomyces cerevisiae
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Additional information on results:
In the suspension assay, MH was found to be positive. Mutagenic activity was observed at MH concentrations of 1 µL and 5 µL after a 60-minute incubation with a mouse liver activation system.
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

There were no clear indications of mutagenic activity by MH in any of the microbial assays performed. The toxicity of MH for bacterial and yeast was high and concentrations of 10 µL/plate were too toxic to use.
MH was mutagenic in activation, microbial reversion test conducted as a suspension test.