Phenyl N-(4,6-dimethoxypyrimidin-2-yl)carbamate

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Two mutagenicity studies were performed; the Ames test on strains TA98, TA100; TA1537 and TA1538 showed a mutagenic results with and without metabilc activation. The in-vivo micronucleus test on Swiss mice by oral gavage treatment did not reveal any treatment related effects and was therefore assessed as non-mutagenic.

Link to relevant study records

Reference

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:

1990

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)

Deviations:

no

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Species / strain / cell type:

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

Details on mammalian cell type (if applicable):

Source: Dr. Bruce N. Ames, University of California at Berkeley, U.S.A. (1987)

Metabolic activation:

with and without

Metabolic activation system:

Aroclor induced rat liver S9

Test concentrations with justification for top dose:

- Concentration range in the main test (with metabolic activation): 100 - 5000 pglplate
- Concentration range in the main test (without metabolic activation): 100 - 5000 pglplate

Vehicle / solvent:

Solvent: Dimethylsulphoxide

Untreated negative controls:

yes

Remarks:

DMSO

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

9-aminoacridine

sodium azide

methylmethanesulfonate

other: 2-aminoanthracene; daunomycine

Evaluation criteria:

A test substance was considered negative (not mutagenic) in the Ames test if:
a) The total number of revertants in any tester strain at any concentration was not greater than two times the solvent control value, with or without metabolic activation
b) The negative response should be reproducible in at least one independently repeated experiment

A test substance was considered positive (mutagenic)in the Ames test if:
a) It induced at least a 2-fold, dose related increase in the number of revertants with respect to the number induced by the solvent control in
any of the tester strains, either with or without metabolic activation. However, any mean plate count of less than 20 was considered to be not
significant. If the test substance showed in the first test only a positive response at one or two concentrations, the assay was repeated with doses just below and exceeding those showing positive effects in the first test
b) The positive response should be reproducible in at least one independently repeated experiment.

Statistics:

See above

Species / strain:

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

Metabolic activation:

with and without

Genotoxicity:

not specified

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

> 5000 ug/plate in preliminary and main test

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

Observations:
Up to 8-14 fold dose-related increases in the number of revertants were observed in strain TAI 537 (with and without metabolic activation) at 3330 and 5000 micrograms/plate in both independent experiments. No increases in revertants were observed with the other strains.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Conclusions:

Interpretation of results (migrated information):
positive with metabolic activation
positive without metabolic activation

The test item was found to be mutagenic in this test system

Executive summary:

The genotoxicity study in vitro was performed as Ames test according to EU-method B.13/14. The cell type used was Salmonella typhimurium, tester strains were TA98, TA100; TA1537 and TA1538. Cytotoxicity was observed at 5000 ug/plat and above. The substance was found to be mutagenic with and without metabolic activation in this test.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (positive)

Additional information

Additional information from genetic toxicity in vitro:

Justification for selection of genetic toxicity endpoint
Guideline study; GLP; Klimisch 1

Justification for classification or non-classification

Based on the data available the substance is not classified or labeled according to Directive 67/548/EEC (DSD) or Regulation 1272/2008/EC (CLP).