Reactions to NCR Paper.

This article focuses on various allergic reactions induced by carbonless copy paper. Carbonless copy paper was introduced in the 1950s to replace the need for carbon paper. The top paper is coated on the undersurface with a suspension of microcapsules containing a colorless dye. The receiving paper is coated on the front surface with a color-developing material. When pressure is applied to the top sheet, the microcapsules are broken, allowing the colorless dye to react chemically with the color-developing material on the bottom sheet. Two types of reactions have been reported from this material. One reaction is allergic contact dermatitis to the chemical color former, paratoluene sulfinate of Michler's hydrol.