Semicarbazide hydrochloride

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1981

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

secondary literature

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1980

Report date:

1981

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

not specified

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Semicarbazide hydrochloride

EC Number:

209-247-0

EC Name:

Semicarbazide hydrochloride

Cas Number:

563-41-7

Molecular formula:

CH5N3O.ClH

IUPAC Name:

semicarbazide hydrochloride

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: ICN-K and K Laboratories, Plainview, N. Y.
- Expiration date of the lot/batch:
- Purity test date: 95-99%

RADIOLABELLING INFORMATION (if applicable)
- Radiochemical purity:
- Specific activity:
- Locations of the label:
- Expiration date of radiochemical substance:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material:
- Stability under test conditions:
- Solubility and stability of the test substance in the solvent/vehicle:
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium:

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing:
- Preliminary purification step (if any):
- Final dilution of a dissolved solid, stock liquid or gel:
- Final preparation of a solid:

FORM AS APPLIED IN THE TEST (if different from that of starting material)

TYPE OF BIOCIDE/PESTICIDE FORMULATION (if applicable)

OTHER SPECIFICS:

Method

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Additional strain / cell type characteristics:

not specified

Species / strain 2

Species / strain / cell type:

S. typhimurium TA 1538

Additional strain / cell type characteristics:

not specified

Metabolic activation:

with and without

Metabolic activation system:

S-9 mix

Test concentrations with justification for top dose:

8,3, 17, 34, 67 and 133µmol
The test item is tested at subtoxic concentrations.

Vehicle / solvent:

the test item was dissolved and diluted in distilled water.

Controls

Untreated negative controls:

not specified

Negative solvent / vehicle controls:

yes

Remarks:

Distilled water

True negative controls:

not specified

Positive controls:

not specified

Details on test system and experimental conditions:

Bacterial Mutagenesis Assays:
Mutagenicity was checked by means both of the plate incorporation test and of the spot test, basically as described in detail by Ames e/ al. (1 ).
Briefly, the plate incorporation test was performed by mixing 50 p.\ of overnight broth cultures (2.5% Oxoid Nutrient Broth No. 2) of each bacterial tester strain, 100 ¡uolf test hydrazine, 0.5 ml of S-9 mix (when needed), and 2.5 ml of molten top agar (0.6% Difco agar:0.5% NaCI solution) supplemented with 10% of a solution of 0.5 mM i_-histidine-HCI:0.5 mM biotin. The mixture was immediately poured on a minimal-glucose agar medium (1.5% Difco agar in Vogel-Bonner Medium E with 2% glucose) solidified layer in Pétriplates (25 ml of medium in 90-mmdiameter plastic plates). A number of assays was also carried out by means of a liquid preincubation test, as described in "Results."
The spot test was performed by placing 10 jul of hydrazine solution in sterile 7-mm filter paper discs at the center of plates over the top agar layer incorporating bacteria and when needed S-9 mix.
All mutagenicity assays were per formed in triplicate, except controls (100 /J of distilled water or dimethyl sulfoxide), which were run on 5 test plates.

Revertant colonies were scored after 48 hr at 37° in the dark.

Results and discussion

Test results

Test results 1

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

not examined

Test results 2

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

without

Genotoxicity:

positive

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

not examined

Remarks on result:

other:

Remarks:

Weak positive

Applicant's summary and conclusion

Conclusions:

SCH was found to be weak without S-9 mix and almost inactive in the presence of S-9 mix in terms of mutagenic potency.

Executive summary:

Sixteen hydrazine derivatives including Semicarbazide hydrochloride were tested for mutagenic activity in the Salmonellamicrosome (Ames) test.

Thirteen of the first 14 compounds listed (81% of the total) including SCH were positive in the Ames test, with a broad range of activity towards the five bacterial strains of Salmonella typhimurium used (TA1535, TA100, TA1537, TA1538, and TA98) and of metabolic behavior in the presence of S-9 mix containing rat liver, mouse liver, or mouse lung postmitochondrial preparations from Aroclor-treated animals.

Under these test conditions, SCH was found to be weak without S-9 mix and almost inactive in the presence of S-9 mix in terms of mutagenic potency.