Building Code Guide 18-10: Breweries and Distilleries

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BCG 18-10: Breweries and Distilleries   

QUESTION: What is the building occupancy classification for breweries and distilleries? When is a Technical Opinion Report required? 

RESPONSE: Breweries and distilleries that mill, grind or crack grain on site will be assigned an H-2 occupancy due to the presence of combustible dust. If an applicant is proposing a lower occupancy classification than H-2, a Technical Opinion Report must be submitted for evaluation to demonstrate that the concentration of combustible dust and conditions do not create a fire or explosion hazard.

An H-2 or H-3 occupancy classification and a Technical Opinion Report may also be necessary when the quantities of flammable liquids, such as alcohol, in an open system, closed system or storage area exceed the Maximum Allowable Quantities (MAQ) per the Oregon Structural Specialty Code (OSSC)/ Oregon Fire Code (OFC).

1. Combustible Dust: 

   1. Bags of pre-milled grain. When malted grain is delivered pre-milled in bags there is a lower risk for combustible dust generation. Therefore, the following apply:
      1. It is assumed the conditions and concentration of dust from the pre-milled grain do not create a fire or explosion risk. Where dust is the only potentially hazardous material present (see section B below), the occupancy classification is assumed to be F-2 for a brewery and F-1 for a distillery.
      2. A 3rd party Technical Opinion Report is not required.
      3. A Hazardous Materials Inventory Statement (HMIS) is not required unless triggered by other materials.
      4. All other requirements in OFC Chapter 22 and OSSC Section 426 for combustible dust apply (e.g. sources of ignition and housekeeping). Dust control may be required based on excessive accumulation of dust as determined at subsequent inspections by the Fire Marshal. In these cases, a mitigation plan is subject to Fire Marshal and/or Building Official approval.
   2. Bags of whole grain or grain delivered in bulk. When malted grain is delivered in bags and cracked on site or delivered in bulk to a silo, bin, or grain room and cracked on site, there is an increased risk for combustible dust generation. Therefore, the following apply:
      1. A 3rd party Technical Opinion Report must be submitted to analyze the fire safety properties of the design and operation of the building and equipment.
      2. The occupancy classification is assumed to be H-2 unless the Technical Opinion Report demonstrates that the concentration of combustible dust and conditions do not create a fire or explosion hazard.
      3. The Technical Opinion Report must be prepared by a qualified expert and approved by the city reviewers.
   3. Existing Breweries and Distilleries. If an existing brewery or distillery with an F occupancy where grain is cracked on site submits a tenant improvement permit or if cited by Portland Fire & Rescue for operating outside the scope of an F occupancy then the applicant shall submit the following information:
      1. A detailed description of grain storage, cracking and conveyance.
      2. A Technical Opinion Report, as needed, to determine occupancy classification (F or H).
      3. Where the operator changes, either an updated Technical Opinion Report to describe the new processes or a letter from the new operator that all processes, equipment and housekeeping measures from the original Technical Opinion Report will be followed. 

2. Flammable Liquids: 

   Distilled spirits and alcohol mixtures with an alcohol content between 20% and 55% are Class IC flammable liquids; above 55% are Class IB flammable liquids. The MAQ is the same whether the alcohol is classified as 1B or 1C. Where limits are exceeded, the building will fall into one of the following classifications:

   • H-2 classification applies where the alcohol is used or stored in normally open containers or systems, OR in closed containers or systems pressurized at more than 15 psi gage.
   • H-3 classification will apply where the alcohol is used or stored in normally closed containers or systems pressurized at 15 psi gage or less.
   • Retail and wholesale sales - Reference OFC Table 5003.1.1 (1) footnote C and OSSC 444.1.1 (3). The quantities of alcoholic beverages in retail and wholesale sales occupancies shall not be limited providing the liquids are packaged in individual containers not exceeding 1.3 gallons.
   • Storage of beer, distilled spirits and wines in barrels and casks are subject to requirements in OFC 40/OSSC 456 but exempt from OFC 50/OSSC 414 and OFC 57/OSSC 444.

   In addition to the flammable liquids distilled on site, where alcohol is delivered in bulk from off site, the occupancy will be F-1 or H depending on the system pressure, and the quantities of alcohol in open system, closed system and storage. 

   Note: In a non-sprinklered building the maximum allowable quantity for alcohol in open use is 30 gallons for an F-1 occupancy. Filling a standard 53-gallon barrel with an open use process will trigger an H occupancy.

   1. New distilleries with listed equipment and quantities below MAQs: Where all equipment is listed by nationally recognized testing laboratories and the quantities of flammable liquids do not exceed the MAQ, the following apply:
      1. A 3rd party Technical Opinion Report will not be required.
      2. If flammable liquid is the only hazardous material present (see section A above), the occupancy classification is assumed to be F-1.
      3. All other requirements in OFC Chapter 57 and OSSC Section 444 for flammable liquids apply.
   2. New distilleries with unlisted equipment and quantities below MAQs: Where equipment is not listed by nationally recognized testing laboratories and the quantities of flammable liquids do not exceed the MAQ, the following apply:
      1. Stills and receivers not listed or labeled by a nationally recognized testing laboratory shall be evaluated as part of a Technical Opinion Report and must submit for approval from the building code appeals board.
      2. If flammable liquid is the only hazardous material present (see section A above), the occupancy classification is assumed to be F-1.
      3. All other requirements in OFC Chapter 57 and OSSC Section 444 for flammable liquids apply.
   3. New distilleries with unlisted equipment and quantities above MAQs: Where the distillery uses equipment that is not listed by a nationally recognized testing laboratories and the quantities of flammable liquids exceed the MAQ, the following apply:
      1. Stills and receivers not listed or labeled by a nationally recognized testing laboratory shall be evaluated as part of a Technical Opinion Report and must submit for approval from the building code appeals board.
      2. The occupancy classification is assumed to be H-2 or H-3, depending on the system pressure, and the quantities of alcohol in open system, closed system and storage.
      3. All other requirements in OFC Chapter 57 and OSSC Section 444 for flammable liquids apply.
   4. Existing distilleries. Where an existing distillery submits a tenant improvement permit or when cited by Portland Fire & Rescue for operating beyond the scope of an F-1 occupancy, the applicant shall submit the following information:
      1. A detailed description of the distillery process.
      2. Where the operator changes, either an updated Technical Opinion Report to describe the new processes or a letter from the new operator that all processes, equipment and housekeeping measures from the original Technical Opinion Report will be followed.  

HISTORY: Implemented May 7, 2018. Revised February 4, 2025.

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