This report describes an unusual case of long-term arsenic exposure, apparently of industrial origin. The afflicted worker suffered from a complex of medical problems of sudden onset. Chemical (atomic absorption spectrometry, AAS) and physical (electron dispersion spectrometry, EDS) examination of the work environment showed long-term deposition of high levels of arsenic in a cleaning bath. When a new acidic cleaning solution was employed, elemental arsenic was apparently volatilized as arsine gas, resulting in sudden toxicity. Periodic reoccurrences of debilitation were explained by repeated use of the acid cleaning solution; each new application released a deeper layer of the metallic arsenic previously deposited on the bath walls electrolytically. The original source of the arsenic appears to have been prior cleaning of arsenic-contaminated agricultural spray equipment.