Health Hazard Evaluations (HHEs)

(2009) Report on an investigation of asthma and respiratory symptoms among workers at a soy processing plant, The Solae Company, Memphis, Tennessee. (Click to open report)
On December 12, 2006, the National Institute for Occupational Safety and Health (NIOSH) received a confidential Health Hazard Evaluation (HHE) request from workers at the Solae Company's plant in Memphis, Tennessee. The requesters described respiratory symptoms and diagnoses, including sinus congestion and asthma, which they attributed to the workplace. They noted exposure to soy materials, lime (calcium oxide (CaO)), microbial contaminants such as mold, and insects. NIOSH investigators conducte... (Click to show more) On December 12, 2006, the National Institute for Occupational Safety and Health (NIOSH) received a confidential Health Hazard Evaluation (HHE) request from workers at the Solae Company's plant in Memphis, Tennessee. The requesters described respiratory symptoms and diagnoses, including sinus congestion and asthma, which they attributed to the workplace. They noted exposure to soy materials, lime (calcium oxide (CaO)), microbial contaminants such as mold, and insects. NIOSH investigators conducted telephone interviews with workers, a union representative, treating physicians, and company management and safety officials. On March 6, 2007, NIOSH investigators visited the plant to observe the process, measure concentrations of airborne dust, collect bulk samples of soy materials, and interview workers about their symptoms and exposures. They later conducted an industrial hygiene survey (July 9-13 and July 30-August 3, 2007). NIOSH investigators collected personal and area air samples from different plant areas, sub-areas, and jobs during the survey. They collected: personal (breathing-zone) air samples for inhalable dust and inhalable soy antigen; personal (breathing-zone) and area air measurements for airborne dust of respirable and thoracic size fractions using a real-time sampler; and area air samples for inhalable dust, inhalable soy antigen, total dust, total endotoxin, selected metals, and particle size distributions. They also collected bulk samples of soy materials from different sub-areas of the plant. From July 23-August 2, 2007, NIOSH investigators also conducted a medical survey of current workers at the plant; it consisted of an interviewer-administered questionnaire; lung function testing, including spirometry, bronchodilator, and methacholine challenge testing; and skin and blood allergy testing. Inhalable dust exposures were highest for the autopack operator, unloading switch operator, and sanitation job categories. Some of the samples from these job categories, as well as from starch dumping, exceeded the Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) for total dust as particulate not otherwise regulated (PNOR) and the American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit values (TLV) for inhalable dust. The task of starch dumping, which produced the highest dust concentrations measured (21.7 mg/m3), was typically done by workers from several different job categories outside their normal shift work, using respiratory protection. Detectable soy antigen air concentrations were measured in all plant areas and sub-areas; the highest geometric mean inhalable soy antigen area concentration was in the flake processing room (308,000 ng/m3). Job categories with the highest geometric mean soy antigen concentration as measured by personal samples included the unloading switch operator (27,540 ng/m3), curd operator (25,960 ng/m3), and unloading lead (14,360 ng/m3). Currently, there are no occupational exposure standards or guidelines specifically for soybean dusts, though the more general PNOR standard does apply to soybean dusts. The highest endotoxin concentration, 217 EU/m3, was measured in the flake processing room; all other endotoxin concentrations were below 50 EU/m3. Calcium was detected in 5 of 67 total dust air samples; if the calcium in these samples was all present as lime (CaO), the highest corresponding lime concentration in air would have been approximately 0.52 mg/m3, a level well below the existing OSHA standard for lime dust. Of the 281 workers currently employed at the plant by the Solae Company, 147(52%) consented to participate in the medical survey and completed the questionnaire. Participation rates varied by worker classification, ranging from 66 of 94 (70%) production workers to 42 of 114 (37%) non-production workers. NIOSH staff conducted lung function testing for 140 of these workers, skin allergy testing for 132, and blood allergy testing for 135. Participating workers at the Solae plant in Memphis had higher than expected prevalences of physician-diagnosed asthma, sinusitis, and wheeze (a symptom of asthma) compared to the U.S. adult population. The prevalences of current and ever physician-diagnosed asthma for participating males were higher than expected based on a survey of the state of Tennessee, but these differences did not reach statistical significance. Among participants with adult-onset, physician-diagnosed asthma, most were diagnosed after hire at Solae. The incidence rate was five times greater after hire than before hire, consistent with a temporal relationship of occupational exposures preceding asthma diagnosis. Compared to non-production workers, production workers were more likely to report asthma-like symptoms that improve away from work. Work-related asthma-like symptoms were also associated with peak dust concentrations. Compared to workers exposed to lower peak concentrations, participants exposed to higher peak concentrations of dust were more likely to report work-related asthma-like symptoms. Additionally, workers who reported seeing or smelling mold in the workplace were more likely to report work-related sinusitis, nasal allergies, and rash compared to workers not reporting this exposure. Fourteen participants (10%) had airways obstruction on spirometry (six borderline and eight mild or worse severity). Eleven (8%) had spirometry results indicating a restrictive pattern. One had both airways obstruction and restriction. Two had a clinically significant response to bronchodilator and 12, including eight without airways obstruction on spirometry, had evidence of bronchial hyperresponsiveness on methacholine challenge testing. The prevalence of positive immunoglobulin E (IgE) to soy among Solae workers was five times greater than the prevalence among a group of comparison workers who were not occupationally exposed to soy, suggesting that immune recognition of soy among Solae workers resulted from occupational exposures. All asthma outcomes were significantly associated with immune response to soy, as measured by soy-specific IgE levels in the blood but not as measured by the skin prick test for soybean allergy. Concentrations of soy antigen and dust exposure were process-related. Compared to workers exposed to lower peak concentrations, those exposed to higher peak dust concentrations (measured by real-time sampling) were more likely to have spirometry indicating airways obstruction and to report work-related asthma-like symptoms. In addition, level of immunoglobulin G (IgG) to soy was associated with inhalable soy antigen level and work classification. Time-weighted-average inhalable soy antigen and dust concentrations were not associated with asthma outcomes in analyses involving all participants. (Click to show less)
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(2008) Contact dermatitis among machinists at an automotive parts manufacturer, Dana Corporation, Bristol, Virginia. (Click to open report)
NIOSH received a request for an HHE at Dana Corporation in Bristol, Virginia from the United Auto Workers, Local 9023. Employees were concerned that poor indoor environmental quality and exposures to chemicals, nylon powder, and dust from grinding machines were causing rashes, nose bleeds, and respiratory problems, and that SRMF levels from induction heaters were causing cancer. Discussions held with union and management representatives determined that dermatitis was the major concern among empl... (Click to show more) NIOSH received a request for an HHE at Dana Corporation in Bristol, Virginia from the United Auto Workers, Local 9023. Employees were concerned that poor indoor environmental quality and exposures to chemicals, nylon powder, and dust from grinding machines were causing rashes, nose bleeds, and respiratory problems, and that SRMF levels from induction heaters were causing cancer. Discussions held with union and management representatives determined that dermatitis was the major concern among employees. On June 13-15, 2006, NIOSH investigators held an opening meeting with management and union representatives and toured the plant to observe work practices. We measured sub-radiofrequency magnetic field (SRMF) levels near the induction heaters, collected bulk metalworking fluid (MWF) samples, evaluated potential acid gas exposures, assessed Local exhaust ventilation (LEV) at the nylon coating operation and the acid dip tank, interviewed employees privately, and performed medical evaluations of the skin. We found machines using MWFs that were not being cleaned between fluid change-out and machines leaking hydraulic oil into MWF reservoirs. Analysis of bulk MWF samples revealed irritant and sensitizing chemical components. Employees had direct skin contact with MWFs, and their training in the safe use and handling of MWFs was inadequate. Of the 72 employees interviewed, 37 reported a prior or current skin problem that they related to work; 11 employees had a rash that was likely work-related at the time of the evaluation. Exposures to SRMFs and acid gases were below OELs. Aerosol cans of antirust spray were used in areas without LEV, and powder had accumulated on horizontal surfaces near the nylon powder coating operation. We recommend developing a comprehensive MWF maintenance program, repairing machines to avoid oil leakage into MWFs, and avoiding the use of MWFs and biocides with irritating and sensitizing components such as formaldehyde-releasing agents. We recommend that employees report potential work-related health problems to their supervisors. The company should educate employees in the safe use and handling of MWFs, methods to prevent work-related skin disease, and appropriate use of PPE. Ventilation should be improved where antirust spray is used and in the nylon powder coating area when drums are charged. (Click to show less)
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(2008) Exposures at a pottery shop, FUNKe Fired Arts (formerly known as Annie's Mud Pie Shop), Cincinnati, Ohio. (Click to open report)
On February 2, 2007, NIOSH received a management request for an HHE at FUNKe Fired Arts, previously known as Annie's Mud Pie Shop, in Cincinnati, Ohio. Although no health symptoms were reported, management was concerned about the potential for employees' long-term exposure to a variety of substances while performing duties at the pottery shop. Exposures of concern included silica from the clay mixing process, elements from mixing dry materials used in the glazes, and VOCs and gases during kiln f... (Click to show more) On February 2, 2007, NIOSH received a management request for an HHE at FUNKe Fired Arts, previously known as Annie's Mud Pie Shop, in Cincinnati, Ohio. Although no health symptoms were reported, management was concerned about the potential for employees' long-term exposure to a variety of substances while performing duties at the pottery shop. Exposures of concern included silica from the clay mixing process, elements from mixing dry materials used in the glazes, and VOCs and gases during kiln firing. Because management requires the use of respirators during clay and glaze mixing, they also requested information on proper respirator use and maintenance. On March 21, 2007, NIOSH investigators held an opening conference and toured the facility to review work processes. On April 11, 12, and May 24, 2007, NIOSH investigators collected eight 8-hour PBZ samples and six area air samples for respirable particulates and silica. Six separate PBZ samples were taken while employees performed specific dust-generating tasks. Wipe sampling for elements was conducted throughout the facility. An ergonomic evaluation of the work processes was performed. During the firing of the kilns, area air samples were taken for elements, NO2, SO2, CO, CO2, and VOCs. CO readings were also taken during forklift activities. None of the PBZ or area air samples exceeded the OSHA PELs or NIOSH RELs for any of the compounds measured, although one employee's exposure for silica was at the NIOSH REL of 0.05 mg/m3. Tasks that created the highest concentrations of respirable silica and particulates included moving bags of raw materials to and from storage and mixing clay. Short-term concentrations of silica were high, reaching 2.0 mg/m3 over 96 minutes of sampling. This exceeded ACGIH's excursion limit of 5 times the TWA TLV. VOCs, NO2, and SO2 concentrations were not detected above the MDC during the kiln-firing process. Although PBZ samples of CO were not taken during the use of the forklift, real-time area CO measurements taken at breathing zone level in the storage room peaked at 204 ppm, exceeding the NIOSH ceiling limit of 200 ppm. Due to the silica content of the clay and the potential for silica exposures to exceed OELs, we recommend using engineering controls to reduce employee exposures. This includes installing LEV in areas where high dust-generating activities take place and improving general building ventilation to allow adequate intake of outdoor air, mixing of indoor air, and dilution of potential airborne contaminants. Engineering controls are the preferred method over respirator use to reduce exposures to workplace contaminants. However, respirators should be used, and a formal respiratory protection program should be implemented until exposures can be reduced below the NIOSH REL and ACGIH excursion limit for silica. We also recommend establishing a health and safety training program for employees on appropriate equipment use and hazards. We further recommend that employees and students practice good hygiene in the workplace. Regular preventive maintenance for the forklift should be performed, eventually transitioning to a low or no emission forklift, and loading dock doors should be kept open while using the forklift to prevent the build-up of CO. (Click to show less)
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(2008) Gro-West Utica, New York. (Click to open report)
In September 2004, the National Institute for Occupational Safety and Health (NIOSH) received a management request for a health hazard evaluation (HHE) at Gro-West Inc. in Utica, New York. Gro-West management submitted the HHE request because they were remediating mold in a house being renovated for future use as a shelter for women and children. NIOSH was asked to evaluate the gaseous chlorine dioxide (ClO2) treatment process with respect to its effectiveness in removing microbial contamination... (Click to show more) In September 2004, the National Institute for Occupational Safety and Health (NIOSH) received a management request for a health hazard evaluation (HHE) at Gro-West Inc. in Utica, New York. Gro-West management submitted the HHE request because they were remediating mold in a house being renovated for future use as a shelter for women and children. NIOSH was asked to evaluate the gaseous chlorine dioxide (ClO2) treatment process with respect to its effectiveness in removing microbial contamination. NIOSH investigators conducted an evaluation in November and December 2004. Traditional and newer techniques for evaluating microbial contamination were used under field conditions to evaluate the ClO2 treatment effectiveness. The evaluation was performed in a microbially contaminated house, which had an undetected roof leak for an extended period that resulted in large areas of visible microbial growth. Concentrations of culturable fungi and bacteria, total fungi determined by microscopic count and polymerase chain reaction (PCR) assays, endotoxin, and (1-->3)-B-D-glucan were determined before and after the house was treated with ClO2. Area air samples were collected and analyzed for volatile organic compounds (VOCs) present in the house before and after ClO2 treatment to see which VOCs were generated by the ClO2 treatment. Wipe samples of walls were collected for chloride, chlorate, and chlorite ion decontamination by-products before and after ClO2 treatment. Culturable bacteria and fungi concentrations and total fungal spore counts (as determined by spore trap and PCR) decreased significantly after the ClO2 treatment. However, microscopic analyses of tape samples collected from surfaces after treatment showed that fungal structures were still present on surfaces after ClO2 treatment. No significant differences in airborne endotoxin and (1-->3)-B-D-glucan concentrations were measured in the house before and after ClO2 treatment. An increase in chloride, chlorate, and chlorite ions occurred after ClO2 treatment, which was expected because these compounds are some of the end products of ClO2 disinfection. Due to the potential for health effects from residuals present after ClO2 treatment, additional clean-up techniques, such as using air cleaners and cleaning surfaces using high efficiency particulate air (HEPA) filter vacuums to reduce concentrations of spores and microbial components, were recommended. (Click to show less)
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(2008) Petersen-Dean Roofing Systems, Phoenix, Arizona. (Click to open report)
On October 29, 2004, the National Institute for Occupational Safety and Health (NIOSH) received a request from the United Union of Roofers, Waterproofers, and Allied Workers Local 135 to conduct a health hazard evaluation (HHE) among Petersen-Dean Roofing Systems employees at a job site in Phoenix, Arizona. The request listed silica and noise as potential hazards to roofers. This is one of four HHE requests received from the union asking NIOSH to examine silica and noise exposures among roofers ... (Click to show more) On October 29, 2004, the National Institute for Occupational Safety and Health (NIOSH) received a request from the United Union of Roofers, Waterproofers, and Allied Workers Local 135 to conduct a health hazard evaluation (HHE) among Petersen-Dean Roofing Systems employees at a job site in Phoenix, Arizona. The request listed silica and noise as potential hazards to roofers. This is one of four HHE requests received from the union asking NIOSH to examine silica and noise exposures among roofers in Arizona. On January 11-12, 2005, NIOSH investigators conducted an HHE at a residential work site in Phoenix, Arizona. Dust and noise measurements were taken during residential roofing operations. In addition, bulk samples of roof tile dust were collected to determine the silica content. NIOSH investigators selected homes where employees were cutting and laying roof tiles throughout the day. Noise exposures for the five roofers ranged from 85.5 to 96.3 decibels on an A-weighted scale (dBA). All full-shift time-weighted average (TWA) noise values exceeded the NIOSH recommended exposure limit (REL), three exceeded the Occupational Safety and Health Administration (OSHA) action level (AL), and none exceeded the OSHA permissible exposure limit (PEL). The 8-hour TWA for the total dust samples collected on employees ranged from 1.7 to 16 mg/m3, and for respirable dust samples, from 0.3 to 2.9 mg/m3. The respirable silica 8-hour TWAs collected on employees ranged from 0.04 to 0.44 mg/m3. One TWA for total dust exceeded the OSHA PEL of 15 mg/m3 for particulate not otherwise regulated. Respirable dust sampling results indicate that four of seven TWAs exceeded the general industry OSHA PEL, and three TWAs exceeded the construction industry OSHA PEL for respirable silica. Six of the seven TWAs for respirable silica also indicated concentrations exceeding NIOSH and the American Conference of Governmental Industrial Hygienists criteria. Three TWA noise values exceeded the OSHA AL of 85 dBA, and all TWA results exceeded the NIOSH REL. Medical screening was conducted on February 22-24, 2005. Employees from all four roofing companies were invited to participate if they had at least 5 years of experience as a roofer. The medical screening included a questionnaire, lung function test (spirometry), and a chest x-ray. Of the 118 employees who participated in all three tests, 13 were Petersen-Dean employees. Most roofers who participated in the medical screening had normal lung function. None of those with abnormal lung function had moderate or severe impairments. After controlling for the effects of smoking, NIOSH investigators found that lung function decreased with increasing years of dry cutting cement tiles. No chest x-rays showed findings consistent with silicosis. An occupational health hazard due to exposures to respirable silica and noise existed for employees of Petersen-Dean Roofing Systems. Recommendations for controlling workplace exposures include reducing or eliminating exposures by implementing engineering controls and enforcing the use of personal protective equipment under the OSHA respirator program guidelines. The employer should develop a training program regarding the potential health hazards of respirable silica exposure, and establish an employee medical monitoring program as specified by the OSHA Special Emphasis Program for Silicosis. Additional recommendations are included at the end of this report. (Click to show less)
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