Atmospheric oxidation of poly(oxyethylene) alcohols. Identification of ethoxylated formates as oxidation products and study of their contact allergenic activity

Abstract

Ethoxylated alcohols are widely used as surfactants. In the present study we have continued our investigations on the degradation with time upon air exposure of the ethoxylated alcohols at normal storage and handling. As a result, a new group of ethoxylated formates with the general formula C12H25(OCH2CH2)nOCHO (n = 0-4) was identified in C12H25(OCH2CH2)5OH stored and handled at room temperature. To facilitate the identification work, reference compounds were synthesized. The formates showed no allergenic activity in the sensitization studies performed. In previous investigations on the same ethoxylated alcohol, we have identified formaldehyde and ethoxylated aldehydes among the oxidation products formed. Formaldehyde is a common contact allergen, and the ethoxylated aldehydes were shown to have a sensitizing capacity of the same magnitude as formaldehyde. The instability of the ethoxylated alcohols and formation of oxidation products may give an allergenic contribution to hand eczema caused by work with water and surfactants. To investigate the clinical significance in man an appropriate diagnostic patch testing in exposed humans is required.