Health hazard evaluation report HETA 92-0263-2424, Boise Cascade, Timber and Wood Products Division, Kettle Falls, Washington

In response to a confidential request from employees at Boise Cascade, Timber and Wood Products Division, Kettle Falls, Washington, an evaluation was conducted of exposure to fly ash and smoke emissions from veneer dryers at the facility and around two fluidized bed combustors located adjacent to the site. A case of manganese poisoning had been reported in a worker. Bulk samples of residue collected on the inside and outside surfaces of veneer dryers indicated manganese was present in concentrations ranging from 1,900 to 6,600 micrograms per gram (microg/g). Fly ash collected near the fluidized bed combustors ranged in manganese concentration from 3,300 to 5,200 microg/g. Respirable silica concentrations exceeded the NIOSH recommended exposure limit of 0.05mg/cubic m. The authors conclude that a potential occupational health hazard existed for workers exposed to manganese and silica. The authors recommend specific measures to improve working conditions and health and safety practices at this facility.