Catalytic Air Freshening Diffusers Based on Isopropyl Alcohol - A Major Source of Acetone Indoors

Received: February 20, 2013
Revised: May 27, 2013
Accepted: May 27, 2013
Download Citation: RIS|BibTeX|https://doi.org/10.4209/aaqr.2013.02.0051  

Cite this article:
Geiss, O., Cacho, C.D. and Barrero-Moreno, J. (2014). Catalytic Air Freshening Diffusers Based on Isopropyl Alcohol - A Major Source of Acetone Indoors. Aerosol Air Qual. Res. 14: 177-184. https://doi.org/10.4209/aaqr.2013.02.0051

ABSTRACT

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.

Keywords: Acetone; Catalytic diffuser; Air freshener; 2-Methylpropanal; IAQ