Researchers from the Centers for Disease Control and Prevention (CDC), National Institute for Occupational Safety and Health (NIOSH) conducted an engineering control evaluation at Kraft Atlantic, a producer that manufactures food flavorings and gelatin, to evaluate their manufacturing processes regarding potential exposure to diacetyl and other food-related flavorings; document the effectiveness of existing exposure control techniques; and identify areas where engineering controls may need to be developed or improved. A separate NIOSH team of industrial hygienists conducted an exposure assessment at this facility. Personal sampling and ventilation assessment were conducted to evaluate potential risks during various tasks monitored during the engineering control survey. Diacetyl exposure is of concern at the Boston, Massachusetts, Kraft Foods facility, with all eight (four personal and four area) positive samples for diacetyl being well above the proposed NIOSH recommended exposure limit of 0.02 mg/m3 for eight hours, and the NIOSH proposed REL of 0.09 mg/m3 for short term exposure limit. Several other chemicals that may be of concern were detected at levels below 1 mg/m3. All the chemicals sampled for, with the exception of 2,3 pentanedione, 2,3 hexanedione, and 2,3 heptanedione, are considered Flavoring and Extract Manufacturers Association (FEMA) high priority chemicals for consideration as substances that may pose respiratory hazards in flavor manufacturing workplaces. However, for those chemicals that have Occupational Safety and Health Administration (OSHA) Permissible Exposure Limits (PEL), all samples were below the PELs. The chemicals 2,3 pentanedione, 2,3 hexanedione, and 2,3 heptanedione, are structurally similar chemicals to diacetyl and are increasingly being used as replacements for diacetyl in flavor formulations. There is some concern that these chemicals may exhibit similar or related toxicological properties as diacetyl. Research is currently being conducted to ascertain this. None of the area and personal samples contained detectable amounts of these chemicals. Acetaldehyde was detected at Kraft Atlantic, but well below occupational exposure limits. Acetaldehyde is considered by NIOSH to be a potential carcinogen. Therefore, exposures to this compound should be minimized to the greatest extent possible. Evaluations were based on a variety of tests including air velocity measurements, real-time monitoring, and smoke release observations. Most of the local exhaust ventilation (LEV) systems at Kraft consisted of flexible ducts connected to plastic hoods. The experiments showed that generally there is good capture by all the LEV hoods. All hoods performed well under all test conditions. General and task-specific recommendations are included to control and reduce both diacetyl and dust exposures. General Recommendations: 1. Use engineering controls such as LEV and work practices aimed at reducing dust and chemical vapor generation are primary preventive steps for reduction of exposure. 2. Clean spills immediately. Shovel large dry spills carefully into a waste bag. Workers might need to wear respiratory protection when cleaning spills. 3. Do not clean a dry spill with a brush or compressed air. Vacuum or wet cleaning processes are recommended. 4. Enclose the mixer as much as possible by using lids and, if possible, provide seals on the lids and other access points. 5. Where possible, locate the working area away from doors, windows, and walkways to prevent drafts from interfering with the ventilation and the spreading of dusts. Task-specific Recommendations: 1. The use of ventilation at the barrel opening has been recommended for capture of vapors during transfer of chemicals. For drum filling, the Industrial Ventilation control guidance recommends the use of an annular exhaust hood around the interface between the drum and feed pipe (at the bung hole). The recommended airflow is a minimum of 100 feet per minute (fpm) across the drum cap/bung hole. For flammable liquids, suitable fans and equipment as well as appropriate grounding schemes should be used to prevent the buildup and discharge of static electricity. 2. Since weighing and pouring are often performed on a bench-top workstation, the addition of a ventilated booth for the bench weighing area is recommended to control dust and vapor exposure. 3. Bag dumping and disposal during the tumbler filling operation can potentially create a significant amount of dust. Bag opening, dumping, and disposal of empty bags should be done in a ventilated enclosure. A ventilated bag dump station, consisting of a hopper outfitted with an exhaust ventilation system to pull dusts away from workers as they open, dump, and discard bags of powdered material, is frequently used in bag dumping operations and should be considered for this facility.