Hazards of Isocyanates

THE incidence of respiratory illness amongst workmen manufacturing and using various isocyanate products has been one of the most fascinating and controversial problems of toxicology arising in the years since the last World War. These products are of immense technical and commercial importance. During the last 10 years their use has increased many fold, and it will be obvious from the remarks of Dr. Lowe that compounds of this type are finding their way into an increasing number of industries. In my opening sentence I described the medical problems as "fascinating and controversial". They are fascinating in that violent symptoms may follow minimal exposure. GOLDBLATT (1956) referred to the absence of a mathematical relationship between the exciting dose, and the intensity of the response. They are controversial in that, despite the vast number of papers describing both clinical and experimental findings, that have been published since the original observations of FUCHS and VALADE (1951), there is still no agreement on the biological mechanisms involved in the production of the effects that occur in man. This arises partly from the difficulty