BCAB #1840

February 20, 2020

Re: Occupancy Classification of a Flour Mill

Project Description

The project is a proposed flour mill operation to be located in an existing fully sprinklered two storey building containing multiple suites of medium hazard industrial occupancy. The flour mill will occupy one suite of about 894 m2, which is approximately 20% of the building area it is located in.

The production capacity of the mill is about 1.5 metric tonnes of finished flour product from 2 metric tonnes of grain, per hour. It is proposed the mill would operate about 9 hours per day.

The flour mill’s dust collection equipment is designed to contain dust within the equipment, and manage flash fires and primary explosions through explosion venting ducted to the exterior of the building.

Applicable Code Requirements

Sentence 3.1.2.1.(1) of Division B and the definitions of medium-hazard industrial occupancy and high-hazard industrial occupancy from Sentence 1.4.1.2.(1) of Division A of the British Columbia Building Code 2018.

3.1.2.1.(1) Except as permitted by Articles 3.1.2.3. to 3.1.2.6., every building or part thereof shall be classified according to its major occupancy as belonging to one of the Groups or Divisions described in Table 3.1.2.1. (See Note A-3.1.2.1.(1).)

High-hazard industrial occupancy (Group F, Division 1) means an industrial occupancy containing sufficient quantities of highly combustible and flammable or explosive materials which, because of their inherent characteristics, constitute a special fire hazard.

Medium-hazard industrial occupancy (Group F, Division 2) means an industrial occupancy in which the combustible content is more than 50 kg/m2 or 1200 MJ/m2 of floor area and not classified as a high-hazard industrial occupancy.

Decision being Appealed (Local Authority’s Position)

The local authority has determined that the subject flour mill operation is classified as a Group F, Division 1 high-hazard industrial occupancy, consistent with the guidance offered in Note A-3.1.2.1.(1) which lists flour mills as an example of a Group F, Division 1 major occupancy. Dust collection and dust control are mandatory requirements in the British Columbia Fire Code notwithstanding the major occupancy classification.

Appellant's Position

The appellant maintains that the subject flour mill operation can be classified as a Group F, Division 2 medium hazard occupancy. The equipment is designed to contain and manage fire hazards of flash fires and/or dust explosions, and housekeeping required by other regulations manages dust buildup. The flour mill operation should not be considered to be a special fire hazard because of the features for eliminating the risk of fires or explosions.

Appeal Board Decision #1840

It is the determination of the Board that the default major occupancy classification of the subject flour mill is a Group F, Division 1 high-hazard industrial occupancy.

Reason for Decision

• The decision is consistent with the guidance offered in Note A-3.1.2.1.(1).
• The appellant has not provided sufficient information to demonstrate that the subject flour mill does not constitute a special fire hazard.

Lyle Kuhnert

Chair, Building Code Appeal Board