Massachusetts Experience with Toluene Di-isocyanate

Fifteen plants engaged in operations involving polyurethane were visited. Air studies were made in 13 plants and correlated with the clinical findings. Forty-eight accepted and 71 questionable cases of intoxication involving upper respiratory tract irritation, including 11 cases of bronchitis and disabling bronchospasm, were noted. In one plant, concentrations above 0.1 ppm were found, whereas the highest concentration in the workroom air in the other 12 plants was 0.07 ppm. It is concluded that the maximum allowable concentration (MAC) of 0.1 ppm is too high, and should be 0.01 or 0.02 ppm.