Contact allergy due to colophony (VIII). The sensitizing potency of commercial products: an investigation of French and German modified-colophony derivatives.

The sensitizing capacity of 7 commercial modified-colophony products of different origins (esters, polyterpene-modified, phenol-modified, resinate, polymerisate) were studied experimentally in guinea pigs by means of a modified Freund's complete adjuvant (FCA) method. All products showed a weak sensitizing power, but a moderate to strong irritant effect. Within this group, the strongest response was obtained with the calcium resinate. As most of these products are used commercially in paints and lacquers, the risk of acquiring specific hypersensitivity must be considered low.