Volume 14, No. 1, February 2014, Pages 177-184 PDF(569 KB)
Catalytic Air Freshening Diffusers Based on Isopropyl Alcohol - A Major Source of Acetone Indoors
Otmar Geiss, Carmen Del Cacho, Josefa Barrero-Moren
European Commission, Joint Research Centre, Institute for Health and Consumer Protection, Via E.Fermi 2749, 21027 Ispra (Va), Italy
Air fresheners are used in indoor environments for perfuming the ambience and/or masking unpleasant smells. There are several types of air fresheners on the market including those belonging to the family of catalytic diffusers. The fuel of these devices is frequently 2-methylpropanol, which, while operating, is oxidised to acetone. The acetone emission of a catalytic diffuser was measured for two fragrances under controlled laboratory conditions as well as in a private household. Emission rates were 530 mg/h and 660 mg/h respectively. Acetone concentrations of approximately 700 µg/m3 were measured in a private household three hours after the diffuser was extinguished. Besides isopropyl alcohol, one of the two fragrances contained 2-methylpropanol as a fuel component, which is oxidised to 2-methylpropanal. The emission rate for 2-methylpropanal was 11 mg/h. Catalytic diffusers containing isopropyl alcohol as fuel were identified as being a major indoor source of acetone. Although not a legal requirement, the secondary formation of acetone should be included in product information along with a list of product constituents. As an alternative, a less easily oxidisable solvent could be used.
Catalytic diffuser; Air freshener; Acetone; 2-Methylpropanal; IAQ.