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EC number: 946-188-6 | CAS number: -
The substance was found to be a non-sensitiser in chemico (direct peptide reactivity assay according to OECD test guideline 442C, GLP study). Applying the integrated approach recommended in the OECD IATA guideline on skin sensitisation, this result was combined with other complementary information in a Weight-of-Evidence approach. As a result, there was sufficient evidence to conclude on the absence of sensitising properties of this multi-constituent substance (“reaction mass of cucurbituril, cucurbituril and cucurbituril”). This conclusion is based on read-across information from cucurbituril hydrochloride hydrate, together with other supporting evidence. The analogue substance cucurbituril hydrochloride hydrate was not a skin sensitiser in a GLP guideline study according to OECD TG 429. The analogue substance has a similar structure containing identical monomer units and functional groups, has a similar toxicity profile and similar physico-chemical properties (cf. data matrix). In addition, the following lines of evidence support the read-across:
- the physico-chemical properties of “reaction mass of cucurbituril, cucurbituril and cucurbituril” suggest a lack of penetration into viable epidermis;
- the lack of structural alerts and the prediction of “non-sensitiser” with the VEGA CAESAR QSAR model, 2018 version);
- the lack of protein reactivity in the OECD 442C assay;
- the lack of activity in in vitro skin irritation and genotoxicity assays; and
- the lack of formaldehyde release in artificial sweat experiments.
Given that none of several different lines of evidence gives any indication of a sensitising potential, the overall confidence level in the assessment is high. The adaptation of information requirements (here: a battery of in vitro sensitisation tests) according to Annex XI (REACH) provisions (based on weight of evidence, including read-across) is therefore considered adequate.
Individual Body Weights for all Animals with Group Means
Test group name
Initial body weight (g)
Terminal body weight (g)
Negative vehicle control (AOO)
CUCURBITURIL 25% (w/v) in AOO
CUCURBITURIL 10% (w/v) in AOO
CUCURBITURIL 5% (w/v) in AOO
Positive control (25% (w/v) HCA in AOO)
*: Terminal body weights were measured on Day 6.
#: = (Terminal Body Weight – Initial Body Weight) / Initial Body Weight x 100
DPM, DPN and Stimulation Index Values for all Groups
Test Group Name
Measured DPM / group
Number of Lymph Nodes
Background (5% (w/v) TCA)
The purpose of this study was to determine the skin sensitisation potential of CUCURBITURIL test item following dermal exposure in the Local Lymph Node Assay. Study performed to OECD Guidelines for Testing of Chemicals No. 429 “Skin Sensitisation: Local Lymph Node Assay”(22 July 2010) Commission Regulation (EC) No 440/2008 of 30 May 2008, B.42. “Skin Sensitisation: Local Lymph Node Assay” (Official Journal L 142, 31/05/2008) as amended by Commission Regulation (EU) No 640/2012 of 6 July 2012 (Official Journal L 193, 20/07/2012).
In conclusion, under the conditions of the present assay, CUCURBITURIL, tested in a suitable vehicle, was shown to have no sensitisation potential (non-sensitizer) in the Local Lymph Node Assay.
The substance does not fill the requirements for skin sensitisation 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.
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