Some hazards in the manufacture and use of plastics.

The expansion of the plastics industry during the last few years has introduced the possibility of hazards from new polymers and from modifications to old products. The first two sections of this paper deal with the diminishing incidence of dermatitis in synthetic resin plants using formaldehyde and with the toxic properties of some chemicals added during the manufacture of polyvinyl chloride compositions. After a brief reference to the hazards of catalysts used in the manufacture of new polymers in the polythene series, an account is given of the dangers of polytetrafluoroethylene. At high temperatures this important new polymer gives rise to decomposition products that may be harmful when inhaled, and smoking contaminated tobacco is one of the commonest ways in practice by which workmen may be affected. Animal experiments have confirmed the dangers of excessive heating of this polymer although the symptoms differ from those in human beings so that it is still not possible to incriminate any one of the products evolved at these temperatures. In a description of the hazards of manufacture of copolymers of butadiene that are new to this country the toxic properties of the monomers are given in some detail since