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Toxicological information

Genetic toxicity: in vivo

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Administrative data

Endpoint:
in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus
Type of information:
experimental study planned
Study period:
The test will be conducted after a final decision on the requirement to carry out the proposed test has been taken and a deadline to submit the information required has been set by the Agency.
Justification for type of information:
TESTING PROPOSAL ON VERTEBRATE ANIMALS

NON-CONFIDENTIAL NAME OF SUBSTANCE:
- Name of the substance on which testing is proposed to be carried out: 7,7,9-trimethyl-4,13-dioxo-3,14-dioxa-5,12-diazahexadecane-1,16-diylbismethacrylate and 7,9,9-trimethyl-4,13-dioxo-3,14-dioxa-5,12-diazahexadecane-1,16-diylbismethacrylate (CAS No. 72869-86-4)

CONSIDERATIONS THAT THE GENERAL ADAPTATION POSSIBILITIES OF ANNEX XI OF THE REACH REGULATION ARE NOT ADEQUATE TO GENERATE THE NECESSARY INFORMATION:
- Available GLP studies: No adequate and reliable GLP studies addressing genetic toxicity in vivo are available with the test substance itself or similar substances defined according to the general rules for grouping of substances and read-across approach laid down in Annex XI, Item 1.5, of Regulation (EC) No. 1907/2006.
- Available non-GLP studies: No adequate and reliable non-GLP studies addressing genetic toxicity in vivo are available with the test substance itself or similar substances defined according to the general rules for grouping of substances and read-across approach laid down in Annex XI, Item 1.5, of Regulation (EC) No. 1907/2006.
- Historical human data: not available
- (Q)SAR methods: not applicable to assess the full scope of an in vivo genetic toxicity study
- In vitro methods:

A reliable GLP-compliant in vitro genetic toxicity study is available (reference 7.6.1-1). In addition two reliable publications regarding in vitro genetic toxicity study are available (reference 7.6.1-2 and 7.6.1-3).
An Ames test was conducted in 2009 with reaction mass of 7,7,9-trimethyl-4,13-dioxo-3,14-dioxa-5,12-diazahexadecane-1,16-diylbismethacrylate and 7,9,9-trimethyl-4,13-dioxo-3,14-dioxa-5,12-diazahexadecane-1,16-diylbismethacrylate according to OECD Guideline 471 which was judged to be negative (reference 7.6.1-1). Briefly, in two independent experiments, the Salmonella typhimurium strains TA 97a, TA 98, TA 100, TA 102 and TA 1535 were exposed to the test substance dissolved in DMSO using either the preincubation or the plate incorporation method. Test substance concentrations of 50, 150, 500, 1501 and 5004 µg/plate were selected for the plate incorporation test with and without metabolic activation. In the second experiment, 312, 624, 1247, 2493 and 4986 µg/plate were selected for the preincubation method with and without metabolic activation. No signs of cytotoxicity were observed up to and including the limit concentration. Up to 5000 µg/plate, the test substance did not induce an increase in the mutation frequency of the tester strains in the presence and absence of a metabolic activation system. Appropriate reference mutagens were used as positive controls and showed a distinct increase of induced revertant colonies. Under the conditions of this experiment, the test substance did not show mutagenicity in the selected S. typhimurium strains in the presence and absence of metabolic activation.
An in vitro micronucleus assay was conducted in 2001 with the test material which was judged to be ambiguous (reference 7.6.1-2). The induction of micronuclei by the test material dissolved in DMSO was investigated in Chinese Hamster lung fibroblasts (V79). Cytotoxicity was evaluated in a preliminary study to define concentration ranges for the main study. In two independent experiments, the cells were exposed to the test material at concentrations of 11.75, 23.5, 35.25 µg/mL for 24 h in the absence of metabolic activation. At cytotoxic concentration levels of the test substance (≥ 24 µg/mL) the numbers of micronuclei were slightly increased in the absence of metabolic activation. Ethyl methanesulphonate was used as positive control and produced a distinct increase in micronuclei frequency indicating that the test conditions were adequate. Thus, under the conditions of this experiment, the potential of the test substance to induce micronuclei is equivocal.
An in vitro gene mutation assay (HPRT test) was conducted in 1998 with the test material which was judged to be negative (reference 7.6.1-3). The mutagenic potential of the test material dissolved in DMSO was investigated in Chinese Hamster lung fibroblasts (V79). Initial cytotoxicity of the test substance on day 1 after exposure was indicated by cell numbers plating efficiency. The cells were exposed to the test material at concentrations of 11.75, 23.5, 35.25 µg/mL for 24 h in the absence of metabolic activation in three replicate cultures. A dose-dependent decrease of cell numbers caused by increasing concentrations was observed. No mutagenic activity of the test material was detected. Ethyl methanesulphonate was used as positive control and produced a distinct increase in mutant frequency indicating that the test conditions were adequate. Thus, under the conditions of this experiment, the test substance did not show mutagenicity in V79 cells without metabolic activation.
Due to the positive result in the in vitro micronucleus test without metabolic activation at cytotoxic concentration a micronucleus test in vivo should be conducted to conclude on genotoxic potential of the test substance.


- Weight of evidence: no weight of evidence data available

- Grouping and read-across: no read-across data available

Data source

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
GLP compliance:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
7,7,9(or 7,9,9)-trimethyl-4,13-dioxo-3,14-dioxa-5,12-diazahexadecane-1,16-diyl bismethacrylate
EC Number:
276-957-5
EC Name:
7,7,9(or 7,9,9)-trimethyl-4,13-dioxo-3,14-dioxa-5,12-diazahexadecane-1,16-diyl bismethacrylate
Cas Number:
72869-86-4
Molecular formula:
C23H38N2O8
IUPAC Name:
7,7,9(or 7,9,9)-trimethyl-4,13-dioxo-3,14-dioxa-5,12-diazahexadecane-1,16-diyl bismethacrylate

Test animals

Species:
rat

Administration / exposure

Route of administration:
oral: gavage

Results and discussion

Applicant's summary and conclusion