Registration Dossier
Registration Dossier
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EC number: 266-235-8 | CAS number: 66204-44-2
Endpoint summary
Administrative data
Description of key information
Key value for chemical safety assessment
Skin sensitisation
Endpoint conclusion
- Endpoint conclusion:
- adverse effect observed (sensitising)
- Additional information:
In a Guinea pig maximisation test conducted according to OECD guideline 406 it has been shown that MBO is an extreme sensitizer. Supporting evidence came from patch tests in humans ( Numerous formaldehyde releasers were tested in the study published by Geier et al. The substance has been shown to induce the highest frequency of contact allergy).
Migrated from Short description of key information:
In a Guinea pig maximisation test (GPMT) presented by Tiwari 2001, no evidence of skin sensitisation was detected. However, the concentration of the test substance was not sufficient for induction (only 4/20 animals showed reactions other than the control values) limiting the validity of this study.
In a 2nd GPMT conducted according to OECD guideline 406 (Coleman 2001), it has been shown that the test substance is an extreme sensitizer. This study has some limitations: 1) no documentation of skin effects after induction (but results of the pilot study are available and positive results obtained in the main study); 2) for challenge 75% test substance in distilled water was used which should normally result in irritant effects and there is some contradiction between the results in this pilot study and the OECD guideline study 404 on skin irritation. However, the positive outcome of this study was validated by negative results in controls. In conclusion, the limitations of the study are not sufficient to disprove the outcome of this study.
The results of this study are confirmed by Anderson et al. (1984) using also the GPMT. A moderate irritant concentration was applied for intradermal (0.5% in water) and topical (10%) induction as well as non-irritant concentrations (0.1, 0.5, or 1.0%) for challenge. A positive reaction in 60% of exposed animals was detected indicating strong skin sensitizing activity. Ambiguous results were obtained at a challenge concentration of 0.1% (2/20 positive, control 1/19).
Respiratory sensitisation
Endpoint conclusion
- Additional information:
There is evidence for skin sensitizing properties of the substance in humans and experimental animals.
Justification for classification or non-classification
Proposal for classification and labelling of the substance: May cause sensitization by skin contact, R43.
According to GHS: Skin sensitizing 1A
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