Safety Aspects of Handling Isocyanates in Urethane Foam Production

Chemicals in any form can be safely stored, handled or used if the physical, chemical, and hazardous properties are fully unders tood, and if proper precautions, including the use of adequate safeguards and personal protection equipment, are taken. In this paper , the chemicals to be considered are the g roup of chemicals known as polyisocyanates, a n d the methods of every-day handling of them is impor tant and involves a number of safety precautions. The word " isocyanates " , as used today, covers a small g roup of polyfunctional organic chemicals which are being used in increasing quantities in widely varying industries. The most common isocyanate (see Table I) is toluene diisocyanate, which is a mixed isomer of 2:4 and 2:6 toluene diisocyanate used in the product ion of rigid and flexible urethanes and urethane coatings. Other common isocyanates a re methylene bis (4 phenyl isocyanate), which is being used in increasing quantities in the product ion of rigid urethanes, and as a bonding agent for elastomers and textile fibres, a n d naphthalene 1:5 diisocyanate, used quite extensively in the product ion of solid urethane elastomers. Polyisocyanates have assumed importance as the building units of high molecular weight polymers having properties of adhesives, plastics, rigid or elastic foams, and synthetic rubbers.