Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Endpoint:
in vivo mammalian cell study: DNA damage and/or repair
Remarks:
In vivo mammalian alkaline comet assay
Data waiving:
other justification
Justification for data waiving:
other:
Justification for type of information:
JUSTIFICATION FOR DATA WAIVING
Based on an ECHA decision on a testing proposal (decision number TPE-D-2114576945-30-01/F), an in vivo mammalian alkaline comet assay (Annex VIII, Section 8.4., column 2; test method: OECD TG 489) in rats, oral route, in liver, glandular stomach and duodenum tissues has been requested by ECHA. The study is currently planned and will be conducted in 2023.

The OECD TG 489 study will follow the study design specifications made by ECHA:
According to OECD TG 489 (paragraph 31), the comet assay can be performed in either sex, however if there is data demonstrating relevant differences between males and females then a study in both sexes is encouraged. The test is conducted in male rats as there are no data on differences in sensitivity between sexes. Furthermore, the oral route is chosen as it is considered the anticipated route of human exposure. In line with OECD TG 489, the test is performed by analysing tissues from liver as primary site of xenobiotic metabolism, glandular stomach and duodenum as sites of contact. According to the specifications of the study design made by ECHA, a preliminary range-finding study should be considered if there are no suitable data available from other relevant studies. Thus, a dose-range finding study will be conducted to identify the maximum tolerated dose (MTD) for the main test.

Due to the high workload of the laboratories, the deadline of 30 November 2022 specified in ECHA decision TPE-D-2114576945-30-01/F cannot be met. The draft report is planned to be available in 2023 (see laboratory statement attached). This section will be updated with the results of the in vivo mammalian alkaline comet assay presumably end of 2023.

Data source

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 489 (In vivo Mammalian Alkaline Comet Assay)
GLP compliance:
yes
Type of assay:
mammalian comet assay

Test material

Constituent 1
Chemical structure
Reference substance name:
Product obtained by rectification during the manufacturing process of Dihydromyrcenol
Molecular formula:
C10H18
IUPAC Name:
Product obtained by rectification during the manufacturing process of Dihydromyrcenol

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female

Administration / exposure

Route of administration:
oral: gavage
Duration of treatment / exposure:
2 treatments at approximately 24 hour intervals
Post exposure period:
2-6 hours after the final administration
No. of animals per sex per dose:
5 males per treated group
3 male animals for positive control group

both sexes should be considered if any existing toxicity, metabolism or exposure data indicate a toxicologically meaningful sex difference.

Examinations

Tissues and cell types examined:
Liver (other tissues/organs can be selected depending on the proposed use for exposure to the test substance)
Details of tissue and slide preparation:
150 cells analysed per tissue (50 cells scored per each of three replicate slides)
Evaluation criteria:
number of heavily damaged cells (hedgehogs, clouds, ghost cells)
% tail intensity and tail moment

Results and discussion

Applicant's summary and conclusion