Tire manufacturing, nitrosamines

A Health Hazard Evaluation of Nitrosamines in a Tire Manufacturing Plant... 

Air Samples NMOR, NDMA, and NPYR were found during the first NIOSH visit in air samples collected at a tire manufacturing plant in Maryland. One process sample, collected at a feedmill, contained 250 yg/M3 of NMOR, a level several times higher than has been reported for any airborne nitrosamine at any industrial site (1). Maximum concentrations of NDMA and NPYR found in the hot process areas were 4.4 yg/M3 and 3.4 yg/M3, respectively. Over the following 7 months, ventilation improvements and changes in chemical formulation of the rubber resulted in a 200-fold reduction in NMOR levels and elimination or reduction of other nitrosamines at most sites. Results are shown in Figure 2, and Table I. 

Figure 3. Highest reported N-nitrosamine air samples during various stages of tire manufacturing...

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