In-depth survey report: control technology for new plastics processes at Herman Miller Company, Holland, Michigan, report no. CT-148-14b.
An indepth survey of control technology for reducing exposures to isocyanates at Herman Miller Company (SIC-2522), Holland, Michigan was conducted in May, 1984. Area and personal air samples were analyzed for toluene-2,4-diisocyanate (584849) (TDI), methylene-bis- phenylisocyanate (101688) (MDI), and total isocyanates. Engineering controls consisted of local exhaust ventilation of the foam fill booth, crush and glue table, and injection molding machine, isolation of pumps and mix tanks for the foam cushion line, and monitoring of TDI vapor in the foam fill booth and pump room. All but one TDI sample were below the limits of detection. TDI at a concentration of 20.5 micrograms per cubic meter (microg/m3) was found in a sample obtained in the pump room. The OSHA standard for TDI is 0.02 parts per million. TDI was detected in a personal sample, but could not be quantitated. No MDI was detected in any sample. Total isocyanates were detected in two samples, 92 and 99microg/m3, obtained in the foam filling and molding operations. There is no Federal standard for total isocyanates. The authors conclude that there is a potential hazard due to isocyanates in the foam filling process. Recommendations include improving ventilation and installing airless foam filling systems.