ABSTRACT
Dimethyltetrahydro benzaldehyde is very similar to 2,4-dimethyl-3-cyclohexene carboxaldehyde. Data in various chemical databases such as ChemSpider, ChemIDPlus, PubChem en ECHA are not unambiguous and rather confusing. It is a synthetic chemical, not found in nature and consequently not in essential oils). According to RIFM, it is a mixture of isomers, a colorless liquid with a sweet-green, leafy odor. The Scientific Committee on Consumer Safety in a 2012 Opinion on Fragrance allergens in cosmetic products, has categorized dimethyltetrahydro benzaldehyde as ‘likely fragrance contact allergen by combination of evidence’. Studies in which dimethyltetrahydro benzaldehyde was patch tested in consecutive patients suspected of contact dermatitis (routine testing) with positive results have not been found. In 2000, in Japan, USA and several European countries, 178 patients with known fragrance sensitivity were tested with a series of fragrances and there were 4 (2.3%) positive patch test reactions to dimethyltetrahydro benzaldehyde 5% pet.
