Registration Dossier
Registration Dossier
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EC number: 274-092-8 | CAS number: 69709-01-9
Endpoint summary
Administrative data
Description of key information
The key study for skin irritation, conducted according to OECD TG 404, but not in compliance with GLP, reports that the substance, 1,1,3,3 -tetramethyl-2-[3-(trimethoxysilyl)propyl]guanidine, is corrosive to skin (RIKKK, 1991).
In accordance with Column 2 of REACH Annex VIII, the in vivo eye irritation study (required in Section 8.2.1) does not need to be conducted as the substance is classified as corrosive to skin.
Key value for chemical safety assessment
Skin irritation / corrosion
Endpoint conclusion
- Endpoint conclusion:
- adverse effect observed (corrosive)
Eye irritation
Endpoint conclusion
- Endpoint conclusion:
- adverse effect observed (irritating)
Respiratory irritation
Endpoint conclusion
- Endpoint conclusion:
- no study available
Additional information
1,1,3,3-Tetramethyl-2-[3-(trimethoxysilyl)propyl]guanidine has been tested in an acute dermal corrosion study in the rabbit, conducted according to OECD 404 (RIKKK, 1991). The substance caused necrosis in two out of three rabbits after one hour, and in three animals after four hours, and it was concluded by the study author that the substance is corrosive.
The registration substance contains the guanidine functional group. Guanidine itself (CAS 113-00-8) is a strong base, with a measured pKa of 12.5 (O'Neil M J, 2013), and is classified as corrosive in the CLP Inventory. The pKa of both the registration substance and of guanidine have been estimated using the Chemicalize structure database. The predicted pKa of the registered substance is 12.42, while the value for guanidine is 12.55. The predicted value for guanidine is similar to the experimental pKa of guanidine indicated above.
A pKa of ≥11.5 is considered to indicate potential to cause skin corrosion (Section 3.2.2.2 in Regulation (EC) 1272/2008), therefore the corrosive result is in line with expectation based on the chemical structure.
In conclusion, therefore, based on in vivo data and a predicted pKa value of 12.42, 1,1,3,3-Tetramethyl-2-[3-(trimethoxysilyl)propyl]guanidine is considered to be corrosive to the skin.
In accordance with Column 2 of REACH Annex VII, the in vitro eye irritation study (required in Section 8.2) does not need to be conducted as the substance is classified as corrosive to skin.
O'Neil M J (2013). The MERCK Index. An encyclopedia of chemicals, drugs, and biologicals. Fifteenth Edition. The Royal Society of Chemistry, pp 843, List No. 4597
Chemicalize. http://www.chemicalize.org
Justification for classification or non-classification
Based on the available data, 1,1,3,3-Tetramethyl-2-[3-(trimethoxysilyl)propyl]guanidine, is classified as Corrosive to Skin Category 1B, and Eye Category 1, 'H314; Causes severe skin burns and eye damage' according to Regulation (EC) 1272/2008.
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.
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