Following a visit to a plastic bag sealing plant in July 2016, NIOSH investigators recommended changes to the facility’s local exhaust ventilation to improve air quality, according to a recently published report by the NIOSH Health Hazard Evaluation Program. A manager at the plant had requested the visit after employees expressed concern about the smoke generated by bag-making machines. No health complaints were reported. The plant produced sealed polyethylene bags for shipment to customers. To assess ventilation near the bag-making machines, NIOSH investigators used ventilation smoke tubes to observe airflow. Smoke appeared to be captured effectively by the LEV near the heat-sealing portion of one of the machines, and less effectively close to the operator’s station. The investigators theorized that fans employees placed around the machine to direct smoke away from the operator were interfering with the LEV. At another machine, investigators discovered loose connections, excess dust, and sharp bends in LEV ductwork, all of which can reduce LEV’s effectiveness. According to the HHE report, an exhaust hood on a third machine known as a flatbed bagger was not as effective as the LEV at other machines, which could have accounted for higher levels of carbon monoxide detected near the bagger. NIOSH recommended that the facility hire a ventilation engineer to improve the ductwork and positioning of the LEV and to further evaluate CO exposures. Read NIOSH’s .