Health hazard evaluation report, HETA 2003-0114-2924, Felker Brothers Corporation, Marshfield, Wisconsin.
On December 23, 2002, the National Institute for Occupational Safety and Health (NIOSH) received a request from the International Brotherhood of Boilermakers regarding worker exposures to chromium and nickel compounds during the manufacture of high-quality, corrosive-resistant stainless steel products and fabricated piping systems at the two Felker Brothers Corporation facilities in Marshfield, Wisconsin. Union officials also expressed concerns about potential carcinogenic effects of these exposures. On February 5, 2003, NIOSH investigators made an initial site visit to gather information on stainless steel cutting, welding, grinding, and pickling processes. An in-depth industrial hygiene evaluation was conducted during May 28-29, 2003. In addition, a NIOSH physician conducted private medical interviews with 23 employees. Personal breathing zone (PBZ) air sampling was conducted on employees during stainless steel cutting, welding, grinding, and pickling operations. PBZ air samples were collected for elements (various metal compounds including nickel and chromium), total welding fumes, hexavalent chromium (Cr VI), ozone, nitrogen dioxide, carbon monoxide, and inorganic acids. Carbon dioxide, temperature, and relative humidity were also measured. PBZ air samples indicated the potential for some workers to be exposed to nickel and Cr VI concentrations above the NIOSH recommended exposure limit (REL) and to manganese above the American Conference of Governmental Industrial Hygienists' (ACGIH) Threshold Limit Value (TLV). The highest concentrations for nickel, manganese, and Cr VI occurred during operations in which workers welded inside large stainless steel pipes or welded fins on a large stainless steel pipe. Two detector tube results for ozone also indicated concentrations exceeding the NIOSH REL ceiling limit and the potential to exceed ACGIH, and the Occupational Safety and Health Administration (OSHA) occupational criteria (if continuous welding occurs throughout the work shift) during welding operations inside stainless steel pipes. A total of 23 employees were interviewed. The average tenure at Felker Brothers was 24 years (range: 6 months to 38 years). Seventeen of the 23 employees reported ever having work-related or work-aggravated health problems, mainly upper respiratory/mucous membrane irritation or musculoskeletal injury. Seven of the 23 employees reported current upper respiratory or mucous membrane irritation. All reported that these symptoms were not severe enough to keep them from working. Welding fumes, acid vapors from the pickling tank, general plant dust, and general plant ventilation could contribute to these symptoms. Twelve (52%) of those interviewed were previous smokers, 6 (26%) had never smoked, and 5 (22%) were current smokers. There was no significant relationship between current mucous membrane irritation and smoking status. PBZ air samples indicated the potential for some workers to be exposed to nickel and Cr VI concentrations above the NIOSH REL and to manganese above the ACGIH TLV. Although the potential for exposure to nickel and chromium exists, at the time of our evaluation, the types of cancers linked to exposure to these substances have not been reported among current or former employees of Felker Brothers. Welding fumes, acid vapors from the pickling tank, general plant dust, and general plant ventilation could contribute to irritant symptoms reported by some workers. Engineering controls (i.e., local exhaust ventilation) should be used in areas where sample results indicated exposures exceeding applicable occupational criteria. Other recommendations to reduce worker exposures are provided in the report.