Registration Dossier

Administrative data

in vitro gene mutation study in bacteria
Type of genotoxicity: gene mutation
Type of information:
experimental study
Adequacy of study:
key study
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: study was preformed according to GLP

Data source

Reference Type:
study report
Report date:

Materials and methods

Test guideline
according to guideline
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
GLP compliance:
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Chemical structure
Reference substance name:
Lead cyanamidate
EC Number:
EC Name:
Lead cyanamidate
Cas Number:
Molecular formula:
lambda2-lead(2+) (azanidylenemethylidene)azanide


Species / strain
Species / strain / cell type:
other: S. typhimurium LT2 TA 1535, TA 97a, TA 98, TA 100 and TA 102
Metabolic activation:
with and without
Metabolic activation system:
S9 liver mix
Test concentrations with justification for top dose:
Seven concentrations of the test item, suspended in deionised water (ranging from 5011 to 4.6 µg/plate) were used. Five genetically manipulated strains of Salmonella typhimurium (TA 97a, TA 98, TA 100, TA 102 and TA 1535) were exposed to the test item both in the presence and in the absence of a metabolic activation system (S9) for 48 hours, using the plate incorporation method.
Untreated negative controls:
Positive controls:
Positive control substance:
other: 2_Amino anthracene (2-AA) in DMSO, Benz-a-pyrene (BaP) in DMSO, 4-Nitro-1,2 phenylene diamine in DMSO, Sodium azide in DMSO

Results and discussion

Test results
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Remarks on result:
other: all strains/cell types tested
Migrated from field 'Test system'.

Any other information on results incl. tables

The test item didn’t show mutagenic effects in both experiments. The number of revertant colonies was not increased in comparison with the spontaneous revertants (solvent only).

Cytotoxicity of the test item was not detected. The background lawn was visible and the number of revertants was not significantly decreased.

Therefore it can be stated, that under the test conditions, the test item Cyanamide, lead(2+) salt (1:1) is

not mutagenic in the Bacterial Reverse Mutation Test usingSalmonella typhimurium,strainsTA 97a, TA 98, TA 100, TA 102 and TA 1535.

Applicant's summary and conclusion

Interpretation of results (migrated information):

The presented data are reliable and adequate.
Executive summary:

The test item is considered not mutagenic for the reasons given above.

Also, the test item didn’t show any cytotoxicity towards the bacteria.

The concentration of the element Pb in the highest concentrated test solution (50 g test item/L, nominal) was determined under non-GLP-conditions in the first and the second experiment.

The confirmation tests of the genotype didn’t show any irregularities. The control of the titre was above the demanded value. The numbers of revertant colonies of the positive controls were in the range of the historical data of the laboratory (see page39) and were definitely increased in comparison with the negative controls, as well as showing mutagenous potential of the diagnostic mutagenes.

Spontaneous revertants were within the normal range in comparison with the historical data of the LAUS GmbH.

For these reasons, the result of the test is considered valid.