(54ab) Economical Large-Scale Indoor Release Modeling Using the AIHA Mathematical Models for Estimating Occupational Exposure to Chemicals

Storage and processing of highly hazardous materials indoors is a common industry practice, but creates a challenge for manufactures to ensure adequate safeguards in the event of a release or spill. Indoor releases of toxic and flammable materials provide a challenge to economically model due to extensive time and specialized software requirements to generate results. The use of the American Industrial Hygiene Association (AIHA) Mathematical Models for Estimating Occupational Exposure to Chemicals provides a viable methodology for generating data to be used for emergency response, facility siting, and engineering design recommendations. This presentation will provide an example of modeling multiple sulfur dioxide (SO₂) release scenarios in a large manufacturing environment. The AIHA well mixed room model and two-zone (near field and far-field constant mass emission) model were used to model the SO₂ release scenarios for various release sizes and durations. The model results provided guidance for increased building safeguards, and assisted in the required level of respiratory protection for response to a SO₂release located within the manufacturing area and located in a segregated storage room. The example will cover the building environment variables and assumptions required to model such a scenario, and review the outputs of the models. A cost comparison of both the AIHA mathematical model and traditional methods of modeling indoor release scenarios using tools such as Computational Fluid Dynamic (CFD) models is provided.