Carbamic acid ester

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

Study period:

June 10 to July 6, 1987

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study similar to the guideline, but not under GLP. A bacterial strain to detect cross-linking was not included in the study design.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1987

Report date:

1987

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

Ames et al. Mutation Research 31, 347-364, 1975

Deviations:

yes

Remarks:

No strain suitable to detect cross-linking was included in the study design

GLP compliance:

no

Type of assay:

bacterial reverse mutation assay

Test material

Reference

Name:

Unnamed

Type:

Constituent

Test material form:

liquid: viscous

Method

Target gene:

His+

Species / strain

Species / strain / cell type:

other: S. typhimurium TA 1535, TA 1537, TA 1538, TA 98 and TA 100

Metabolic activation:

with and without

Metabolic activation system:

S9 activation mixture composed of: 0.04 ml S9 liver homogenate, 1.4 uMoles NADP, 5.7 uMoles MgC12, and 4.7 uMoles glucose-6-phosphate, and 70 uMoles sodium phosphate buffer, pH 7.4

Test concentrations with justification for top dose:

1,000, 500, 100, 10 and 5 ug/plate

Vehicle / solvent:

DMSO

Controls

Controls 1

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

yes

Positive controls:

yes

Positive control substance:

other: N-methyl-N-nitro-N-nitrosoguanidine

Remarks:

TA 100 and TA 1535 without metabolic activation

Controls 2

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

yes

Positive controls:

yes

Positive control substance:

9-aminoacridine

Remarks:

TA 1537 without metabolic activation

Controls 3

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

yes

Positive controls:

no

Positive control substance:

2-nitrofluorene

Remarks:

TA 98 and TA 1538 without metabolic activation

Controls 4

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

yes

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene

Remarks:

all strains with metabolic activation

Details on test system and experimental conditions:

METHOD OF APPLICATION: plate incorporation

DURATION
- Incubation period: 60-72 hours at 35 °C

NUMBER OF REPLICATIONS: 3 plates per concentration

DETERMINATION OF CYTOTOXICITY: separate test in TA 98 and TA 100 at 0-5000 ug/mL

Evaluation criteria:

1. The spontaneous revertant levels for each strain when used in either the direct plate assay or the activated plate assay must not differ significantly from the range of historical values.
2. All sterility controls must be negative.
3. All positive controls must demonstrate that the indicator strains are functional with known mutagens as evidenced by an increase of at least three times the number of revertant colonies per plate as the spontaneous revertant controls.
4. To be considered positive for mutagenic activity, the test material should exhibit a dose response effect (increasing numbers of revertant colonies with increased amounts of the test sample).
5. To be considered mutagenic for strains TA l53S, TA 1537, TA 1538 and TA 98, the test sample should produce a positive dose response over three concentrations with the lowest increase in revertants/plate greater than or equal to 3x the solvent control value or the S-9 fraction control value, as applicable.
6. To be considered mutagenic for strain TA 100, the test sample should produce a positive dose response over three concentrations with at least one dose producing an increase in revertants/plate greater than or equal to 3.5 x the solvent control value or the S-9 fraction control value, as applicable.

1-3 are validity criteria
4-6 are criteria for the conclusion mutagenic or non-mutagenic

Statistics:

NA

Results and discussion

Test results

Species / strain:

other: S. typhimurium TA 1535, TA 1537, TA 1538, TA 98 and TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

in a separate cytotoxicity test at 5000 ug/mL (equivalent to 5000 ug/plate)

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

For 5000 ug/plate 100 uL of a stock solution of 52200 ug/mL was used. For the test concentrations the appropriate dilutions of this stock were used.

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 without metabolic activation
negative with metabolic activation

The substance did not exhibit mutagenic effects in the Ames test with and without metabolic activation

Executive summary:

The substance was tested in a plate incorporation assay in Salmonella Typhimurium strains TA98, TA100, TA1535, TA1537 and TA1538 at concentrations up to 1000 ug/plate (cytotoxicity was observed at concentrations comparable to 5000 ug/plate). No increase of the number of revertants was observed with and without metabolic activation. It is concluded that the substance is not-mutagenic to bacteria.