Registration Dossier
Registration Dossier
Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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.
Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 610-513-7 | CAS number: 502421-44-5
Endpoint summary
Administrative data
Key value for chemical safety assessment
Effects on fertility
Description of key information
The conclusions were derived hased on the read across study and the QSAR predictions.
Toxicity to reproduction: other studies
Additional information
Different in silico approaches were applied, including the read-across and QSAR models. In addition, different QSAR tools were used, when possible, in order to apply a consensus approach to enhance the reliability of the predictions. In fact, when multiple models and multiple approaches are combined in a consensus analysis, more accurate predictions can be achieved. In general, the consensus approach was performed according to the precautionary principle and weighting QSAR results more than the read-across results, since they are considered more reliable and scientifically robust.
Justification for classification or non-classification
The experimental result on reproductive toxicity of the source chemical, i.e. Valacyclovir acyclovir, the main metabolite of valacyclovir, does not impair fertility or reproduction in mice (450 mg/kg/day, oral) or in rats (25 mg/kg/day, subcutaneous administration); this result was read-across to L-Valine, N-[(1,1-dimethylethoxy)carbonyl]-, 2-[(2-amino-1,6-dihydro-6-oxo-9H-purin-9-yl)methoxy]ethyl ester, concluding that L-Valine, N-[(1,1-dimethylethoxy)carbonyl]-, 2-[(2-amino-1,6-dihydro-6-oxo-9H-purin-9-yl)methoxy]ethyl ester is NOT REPRODUCTIVE TOXIC.
The QSAR predictions were evaluated as INCONCLUSIVE, since the predictions on rodent male and female were not in agreement.
Additional information
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
