2-thiazolidinylidenecyanamide

Genetic toxicity: in vitro

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:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study according to OECD guideline

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1997

Report date:

1997

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

427-720-1

EC Name:

-

Cas Number:

26364-65-8

Molecular formula:

C4H5N3S

IUPAC Name:

[(1,3-thiazolidin-2-ylidene)amino]formonitrile

Details on test material:

name: Cyanamide, (4,5-dihydroxy-2-thiazolyl)-
molecular formula: C4 H5 N3 S
molecular weight: 127.2
physical state: solid
analytical purity: 98 %

Method

Species / strain

Species / strain 1

Species / strain / cell type:

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

Species / strain 2

Species / strain / cell type:

S. typhimurium TA 102

Metabolic activation:

with and without

Metabolic activation system:

S9-mix of Aroclor 1254 induced rats

Test concentrations with justification for top dose:

see below

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: The solvent used was chosen out of the following solvents, in the order given: water, DMSO, methanol, ethanol, acetone, ethylene glycol dimethylether, and DMF according to information given by the internal sponsor. The order of these solvents is based on their bacteriotoxic effects in preincubation experiments.

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)

NUMBER OF REPLICATIONS: 3 plates each

DETERMINATION OF CYTOTOXICITY
- Method: relative total growth

Evaluation criteria:

A reproducible and dose-related increase in mutant counts of at least one strain is considered to be a positive result.
For TA 1535, TA 100 and TA 98 this increase should be about twice that of negative controls, whereas for TA 1537, at
least a threefold increase should be reached. For TA 102 an increase of about 150 mutants should be reached. Otherwise,
the result is evaluated as negative. However, these guidelines may be overruled by good scientific judgement.
In case of questionable results, investigations should continue, possibly with modifications, until a final evaluation
is possible.

Results and discussion

Test results

Test results 1

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:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 102

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Effects of pH:
- Effects of osmolality:
- Evaporation from medium:
- Water solubility:
- Precipitation:
- Other confounding effects:


RANGE-FINDING/SCREENING STUDIES:


COMPARISON WITH HISTORICAL CONTROL DATA:


ADDITIONAL INFORMATION ON CYTOTOXICITY:

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

Based on the findings of this study the substance is not subject to classification.

Executive summary:

CIT was initially investigated using the Salmonella/microsome plate incorporation test for point mutagenic effects in doses of up to and including 5000 /xg per plate on five Salmonella typhimurium LT2 mutants. These comprised the histidine-auxotrophic strains TA 1535, TA 100, TA 1537, TA 98 and TA 102. CIT was investigated in an independent repeat using preincubation for 20 minutes at 37°C. All other conditions remained unchanged. Doses up to and including 5000 /xg per plate did not cause any bacteriotoxic effects: Total bacteria counts remained unchanged and no inhibition of growth was observed. Evidence of mutagenic activity of CIT was not seen. No biologically relevant increase in the mutant count, in comparison with the negative controls, was observed. The positive controls sodium azide, nitrofurantoin, 4-nitro- 1,2-phenylene diamine, cumene hydroperoxide and 2-aminoanthracene had a marked mutagenic effect, as was seen by a biologically relevant increase in mutant colonies compared to ~he corresponding negative controls. Therefore, CIT was considered to be non-mutagenic without and with S9 mix in the plate incorporation as well as in the preincubation modification of the Salmonella/microsome test.