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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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: 245-876-7 | CAS number: 23779-32-0
Endpoint summary
Administrative data
Description of key information
Skin irritation (OECD TG 404): not irritating
Eye irritation (OECD TG 405): not irritating
Key value for chemical safety assessment
Skin irritation / corrosion
Endpoint conclusion
- Endpoint conclusion:
- no adverse effect observed (not irritating)
Eye irritation
Endpoint conclusion
- Endpoint conclusion:
- no adverse effect observed (not irritating)
Respiratory irritation
Endpoint conclusion
- Endpoint conclusion:
- no study available
Additional information
No information about skin and eye irritation is available for the registered substance, however, reliable data is available for the closely related substance Ureidopropyltrialkoxysilane, mixed methoxy and ethoxy esters (CAS 116912-64-2). The read-across is justified as follows:
READ-ACROSS JUSTIFICATION
To reduce animal testing REACH recommends to make use of a read-across approach where appropriate based on the high accordance in properties relevant for the specific endpoint. In the case of irritation/corrosion relevant properties are structural similarity as well as physical-chemical properties in the same range. In the following paragraphs the read-across approach for [3-(triethoxysilyl)propyl]urea (CAS 23779-32-0) is evaluated point by point.
Read-across hypothesis
Health hazards for both, skin irritation/corrosion and eye irritation, are characterised by local effects exhibited by the test material. Thus, similar toxicokinetics are not considered to be of importance for the development of an appropriate read-across strategy. Therefore, the following read-across justification will solely focus on the similarity of the physical-chemical properties and the structural similarity of the submission substance for [3-(triethoxysilyl)propyl]urea (CAS 23779-32-0) and the read-across substance [3-(trimethoxysilyl)propyl]urea (CAS 23843-64-3).
Both the submission substance and the read-across substance are close structural analogues, differing only in the length of the alkoxy moiety bound to the central atom silane (methoxy vs. ethoxy). Both substances hydrolyse rapidly to the common hydrolysis products [3-(trihydroxysilyl)propyl]urea. The hydrolysis half-lives are approximately 2.4 h at 25°C and pH 7 (relevant for skin and eyes) for [3-(trimethoxysilyl)propyl]urea (CAS 23843-64-3) and 16.4 h at pH7 and 20-25°C for [3-(triethoxysilyl)propyl]urea (CAS 23779-32-0) (see Section 4.1.1.1).
None of the substances does meet the skin and eye irritation inclusion rules by BfR (OECD Toolbox 2.3.0.1132).
The non-silanol hydrolysis products, ethanol and methanol, are not expected to contribute to any local adverse effects.
It is therefore considered appropriate to read-across the available skin and eye irritation data from [3-(trimethoxysilyl)propyl]urea (CAS 23843-64-3) to [3-(triethoxysilyl)propyl]urea (CAS 23779-32-0).
Additional information is given in a supporting report (PFA 2013a) attached in Section 13 of the IUCLID 5 dossier.
Skin irritation:
In a key skin irritation study, conducted in compliance with GLP and according to OECD TG 404, the test substance was not found to be corrosive or irritant (WIL Research Laboratories, Inc., 1996b). Treatment of 3 New Zealand White rabbits with 0.5 ml of the neat test substance for 4 h under semi-occlusive conditions provoked slight erythema (grade 1) but no oedema reactions after 1 h in all 3 animals. The effects were fully reversible within 24 h. Therefore mean values for erythema and oedema over 24, 48, and 72 h was 0 for both endpoints. In conclusion, the test material is not irritant / corrosive under the conditions tested.
Eye irritation:
In an eye irritation study according to OECD TG 405 and GLP, only minor, transient eye irritation was observed following instillation of ureidopropyltrialkoxysilane, mixed methoxy and ethoxy esters in 3 rabbits (WIL Research Laboratories, Inc., 1996c). The scores (mean over 24, 48, and 72 h) of 0 for cornea and iris and the mean scores of 1.7 for conjunctivae and 0.9 for chemosis indicate that the test material would not be considered irritating to the eyes of rabbits.
Justification for selection of skin irritation / corrosion endpoint:
The key study was selected for assessment.
Justification for selection of eye irritation endpoint:
The key study was selected for assessment.
Justification for classification or non-classification
The available data on skin and eye irritation of the registered substance do not meet the criteria for classification according to Regulation (EC) 1272/2008 or Directive 67/548/EEC, and are therefore conclusive but not sufficient for classification.
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.
