Registration Dossier

Administrative data

Description of key information

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:

Skin sensitization

In three well conducted and documented key studies in human volunteers (Section 7.10.4), concentrations of 5% to 20% of the analogue chemicals, dimyrcetol or myrcenol, dihydro derivative, applied to skin were neither irritating nor sensitizing to the skin. In a key human repeated-insult patch test (HRIPT), 20% myrcenol, dihydro derivative, was applied under occlusive patch for 24 -hour periods to the upper backs of 99 test subjects on 3 days/week for a total of 9 applications. After an approximately 2 -week rest period, fresh challenge patches were applied to previously untreated areas on the backs of the test subjects. Under the conditions of this study, the test material failed to produce either dermal irritation or sensitization. In a similarly conducted study, dimyrcetol failed to produce dermal irritation or sensitization at concentrations of 10% (107 test subjects) or at a concentration of 5% (110 test subjects). In a Human Maximization Test in 25 volunteers, dimyrcetol (4%) was applied as occlusive patches to the volar forearms or backs for alternate-day 48 -hour periods. Patch sites were pretreated with 2.5% aqueous SLS under occlusion (24 hours). Following a 10 -day rest period, challenge patches were applied. Dimyrcetol under the conditions of this study did not produce contact sensitization. In a Local Lymph Node Assay (LLNA) in mice, dimyrcetol at concentrations of 0.5% to 25% w/v, failed to produce a 3 -fold or greater increase in lymphoctye proliferation and was rated as unlikely to be a skin sensitizer.

Please refer to Section 13 of this IUCLID file for read-across documentation and rationale for the selection of representative analogue chemicals.

Migrated from Short description of key information:
Human repeated insult patch tests with analogue chemicals at concentrations up to 20% failed to produce either dermal irritation or sensitization.

Respiratory sensitisation

Endpoint conclusion
Additional information:
Migrated from Short description of key information:
No information identified

Justification for classification or non-classification

Dihydromyrcenol would not be considered a skin sensitizer based on the results of human repeated insult patch tests with the surrogate materials dimyrcetol or myrcenol, dihydro derivative, at concentrations as high as 20%. In addition, dimyrcetol failed to produce a positive response in the mouse LLNA test at a maximum concentration of 25%. Dihydromyrcenol would not be classified for contact sensitization under the EU DSD criteria (EU Directive 67/548/EEC), the EU CLP (GHS) criteria (EU Regulation 1272/2008) or the United Nations Globally Harmonized System of Classification and Labelling of Chemicals (UN-GHS)..