Abstract: In June 2003, Employee #1, of Mission Flavors & Fragrances, Inc., Foothill Ranch, CA., began to experience coughing, spitting up mucous, and shortness of breath. Employee #1 was diagnosed with bronchiolitis obliterans due to diacetyl exposure in July 2004. The employer creates powder and liquid food flavors by mixing raw materials into a flavor product. The product then goes through quality control and is packaged and shipped to the customer. Employee #1 was a product mixer who would get a batch card, which is somewhat like a recipe card, and follow its instructions. Employee #1 used Diacetyl, as required by the batch cards, approximately 2 to 3 times per week. The Diacetyl is in liquid form and is used to create a butter flavor. After working for the Employer for 1.5 years, Employee #1 began to experience symptoms. Employee #1 used personal protective equipment, including goggles, work uniform, gloves, hairnet, and a dust mask. Employee #1 had not been trained on the use of a respirator and has had facial hair since he began working for the employer. During the time that Employee #1 worked, no ventilation was provided in the powder room. Employee #1 was unaware and not informed of the hazards of the chemicals he was using while working for the employer.