Potential corrosion of metals by atmospheric organic acids.

Organic acids account for as much as a third of the free acidity in rain in industrialized regions of the earth and as much as two thirds of the free acidity in remote regions. This is of interest in materials degradation studies, as many metals and alloys are known to corrode in the presence of organic acids. Using aged copper field samples, we have conducted ion chromatographic studies which demonstrate that formate and acetate ions are incorporated into surface corrosion layers, where they may play significant roles in metal deterioration.