314. MDI Concentrations During Application of Spray-On Truck Bed-Liners

NIOSH alert: preventing asthma and death from MDI exposure during spray-on truck bed liner and related applications.

“…Typically, respirators should not be used as the primary control for routine operations except during situations such as implementation of engineering controls, some shortduration maintenance procedures, and emergencies. NIOSH exposure assessment data show that the engineering controls at the NIOSH survey sites did not reduce MDI concentrations below the occupational criteria, even at the sites with the best ventilation controls [Almaguer et al 2004]. Airborne MDI monomer concentrations in the spray enclosures during the spray-on application process routinely exceed both the NIOSH 10-minute ceiling limit (0.2 mg/m 3 ) and the OSHA PEL as a 15-minute ceiling concentration (0.2 mg/m 3 ).…”

“…Observations at the surveyed worksites suggest effective exhaust ventilation may have reduced MDI monomer concentrations in the spray enclosure during spray applications [Almaguer et al 2004]. Only one site had an exhaust system designed to effectively capture contaiminants in the spray enclosure; at this site, airborne MDI was reduced to concentrations near the NIOSH REL.…”

“…As a result, NIOSH began a study of the spray-on truck bed lining industry. NIOSH conducted walk-through surveys at spray-on truck bed liner facilities in Washington State, Colorado, Ohio, and Kentucky [NIOSH 2003a;Almaguer et al 2004]. Six sampling surveys were conducted in Ohio and Kentucky.…”

“…Nonmonomeric MDI was detected in the spray enclosure samples and ranged up to 42% of the total isocyanate group. All workers applying spray wore supplied-air, full-facepiece respirators, except for one who wore a supplied-air, half-facepiece respirator [Almaguer et al 2004].…”