3003 W CASINO RD BLDG 45-01 2018-09-20

Page 2of3 GPNPP-06-0309 FPN No. 1: This classification usually includes locations where volatile flammable liquids or flammable gasses or vapors are used but that, in the judgment of the authority having jurisdiction, would become hazardous only in case of an accident or of some unusual operation conditions. The quantity of flammable material that might escape in case of accident, the adequacy of ventilating equipment, the total area involved, and the record of the industry BOE/A/G or business with respect to explosions or fires are all factors that merit consideration in determining the classification and extent of each location." The Boeing Company request that the Paint Hangar Class 1, Division 2 areas as required by 2005 NEC 516 be reduced by 50% as shown on preliminary drawings 45-003-EOB, -EOC, and-EOD (submitted), based on the following design features: 1. The paint hangars have a process ventilation system that supplies air through ceiling diffusers vertically down and is exhausted through floor grates and discharged outside of the building. The airflow during painting mode is approximately 450,000 cubic feet per minute. 2. The ventilation system shall be interlocked with the spray application equipment (paint and solvent wash) to prevent spraying or cleaning operations unless the ventilation system is operating and functioning properly. Spray or cleaning operations shall be automatically stopped if the ventilation system fails. 3. The existing paint hangars at the Boeing Everett site have operated safely for over 20 years under these and similar operating conditions. Per NFPA 33, the concentration of the vapors and mists in the exhaust stream of the ventilation system shall not exceed 25 percent of the lower flammable limit. To verify compliance The Boeing Company hired an outside consultant that conducted tests in all existing paint hangars at Everett to determine the actual concentration of hazardous vapors. Tests were performed by Clayton Group Services, Inc. of Seattle. The results show that the maximum concentration of flammable vapors is less than 1% by volume of air. The LEL concentration was a constant zero percent throughout the sampling period. For more detailed results and test locations see the attached reports and drawings. Occupancy Classification The current painting operation within the existing hangar stores and uses 96 gallons (8 — 12 gallon containers) of solvent (Class 1B Flammable Liquid) and 21C