Health hazard evaluation report: HETA-2007-0033-3074, report on fixed obstructive lung disease in workers at a flavoring manufacturing plant, Gold Coast Ingredients, Inc., Commerce, California.
On October 24, 2006, Gold Coast Ingredients, Inc. requested a Health Hazard Evaluation (HHE) from the National Institute for Occupational Safety and Health (NIOSH) to medically screen workers for occupational lung disease at their Commerce, California, flavoring manufacturing plant. The company was participating in a voluntary special emphasis program for the flavor manufacturing industry, called the Flavoring Industry Safety and Health Evaluation Program (FISHEP). On September 6, 2006, Cal/OSHA had previously requested technical assistance (HETA 2006-0361) from NIOSH for an industrial hygiene and engineering control assessment at the same Gold Coast Ingredients plant to characterize work tasks, processes and procedures, and potential occupational exposures. A secondary goal was to develop recommendations for and evaluate the effectiveness of exposure control techniques. Reports and correspondence regarding the industrial hygiene surveys and the engineering control surveys at the plant were sent to the company previously and are summarized in this HHE report. They are also available in their entirety in the appendices of this report. Medical surveys of workers were conducted during October 30-November 1, 2006 and March 13-14, 2007; industrial hygiene surveys during November 14-16, 2006 and July 11-12, 2007; and engineering control surveys during November 14-16, 2006 and July 9-12, 2007. During the initial medical survey among 41 participants, one of 14 (7%) ever-production workers had severe fixed airways obstruction, later confirmed as bronchiolitis obliterans. Post-hire eye irritation was significantly more prevalent in current production workers (11 of 12, 92%) compared to current nonproduction workers (16 of 29, 55%) (p-value=0.03). On repeat spirometry, 1 of 11 (9%) current production workers was found to have developed new obstruction, with a 1-liter drop in the forced expiratory volume in the first second of exhalation (FEV1). Among 15 ever-production workers from both medical surveys, 2 (13%) had fixed airways obstruction. During the initial industrial hygiene survey, mean full-shift TWA diacetyl air concentrations were 0.46 ppm in the liquid production room, 0.34 ppm in the powder production room, and 0.21 ppm in the pre-production corridor for both area and personal samples. The highest task-based diacetyl air concentration (11.04 ppm) was measured when a worker (in a full-facepiece respirator with organic vapor and particulate cartridges) was pouring diacetyl from a bulk container into smaller containers in the pre-production corridor over a 10-minute period. Mean, full-shift TWA acetoin air concentrations were 0.15 ppm in the liquid production room, 0.09 ppm in the powder production room, and 0.07 ppm in the pre-production corridor. The highest task-based acetoin air concentration (1.05 ppm) was measured during mixing and pouring of a butter flavor in the liquid production room by a worker wearing a full-facepiece respirator with combined organic vapor and particulate cartridges; this activity took 61 minutes. Mean, full-shift TWA acetaldehyde air concentrations were 0.14 ppm in the powder production room, 0.07 ppm in the liquid production room, and 0.07 ppm in the pre-production corridor. A task-based acetaldehyde air concentration of 0.19 ppm was measured during pouring and mixing of ingredients for a fruit flavor in the liquid production room; this activity took 53 minutes. During the follow-up industrial hygiene survey, mean full-shift TWA area diacetyl air concentrations were 0.529 ppm in the liquid production room, 0.483 ppm in the powder production room, 0.098 ppm in the pre-production corridor, and 0.041 ppm in the distribution warehouse. The highest single-area 2-hour air concentration of diacetyl (6.33 ppm) was observed in the spray-drying room while a recipe with diacetyl was being encapsulated. Higher task-based diacetyl concentrations (ranging from 4.75 ppm to 17.38 ppm) were measured during some activities: 1) pouring liquid diacetyl; 2) scooping and sifting flavored powder products; 3) packaging flavored powder products; and 4) adding ingredients into flavor formulations. Mean full-shift TWA acetoin air concentrations were 0.20 ppm in the spray-drying room, 0.163 ppm in the powder production room, 0.077 ppm in the pre-production corridor, and 0.067 ppm in the distribution warehouse. The highest task-based acetoin air concentration (2.78 ppm) was measured during packaging of a dairy-flavored powder product in the powder production room over a 33-minute period. Mean full-shift TWA acetaldehyde air concentrations were 0.44 ppm in the spray-drying room, 0.343 ppm in the powder production room, 0.273 ppm in the liquid production room, and 0.029 ppm in the pre-production corridor. The highest task-based acetaldehyde air concentration (4.02 ppm) was measured during packaging of a powdered dairy-flavored product in the powder production room; this activity took 33 minutes. During the initial engineering control survey, NIOSH investigators performed a walkthrough of the plant to review production processes and provided recommendations on the design and implementation of engineering controls. During the follow-up survey, NIOSH investigators evaluated the local exhaust ventilation system (bench-top and booth-type hoods) installed in the liquid production room. When activated, the ventilated bench-top and booth-type hoods had good overall performance; however, NIOSH investigators made recommendations to further improve the performance and operability of the local exhaust ventilation. NIOSH investigators also recommended that management continue to install ventilation and other engineering controls to minimize exposure to hazardous chemicals in the powder production processes. Additionally, we recommended that workers wear full-facepiece respirators (with NIOSH-certified organic vapor and particulate cartridges) at all times when they are in the pre-production corridor, liquid production room, powder production room, spray-drying areas, or distribution warehouse. Workers who enter these areas should also undergo spirometry testing every three months. Workers with abnormal spirometry or a decline in FEV1 greater than 10% should be removed from exposure to flavoring chemicals until medically evaluated for appropriate restrictions.