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Evaluating and Testing Buildings for Shelter in Place

January 21, 2021

Emergency response planning may direct personnel in some buildings to shelter-in-place (SIP) during a toxic/flammable release. Many of our clients have asked questions such as the following regarding SIP:

  • Do toxics/flammables reach my occupied buildings for selected scenarios?
  • Can people evacuate the building or is it better to SIP?
  • What is the toxic/flammable leak rate into the building?
  • How long can personnel SIP before the inside atmosphere becomes hazardous?
  • What can be done to increase the time that personnel can SIP inside the building?
  • What is the emergency response plan if occupants must stop SIP and evacuate before the outdoor hazard is abated?

To qualify candidate buildings as shelter-in-place, it is crucial that you perform sufficient modeling and testing to fully understand the baseline risk. ABS Group uses the following three (3) stage approach to provide our clients the answers to these questions:

  1. Perform gas dispersion modeling to determine the toxic/flammable environment outside the building
  2. Assess the leakiness of the building through testing to identify major leakage sources
  3. Perform infiltration calculations to determine the duration the building can be used to SIP

What We Cover

During this webinar, we will discuss the fan pressurization testing method used to quantify leak rates in a building and how to use infrared thermography to identify specific locations for remediation. We will also briefly discuss the use of computational fluid dynamics (CFD) and how it can be used to predict the hazardous environment more accurately outside the building during a release. Finally, we will discuss additional strategies that can be implemented to lower risk to occupants and improve an existing building’s potential for use as a SIP.


Kevin Sweeney, Lead Engineer, ABS Group

Kevin Sweeney has 10 years of experience performing facility siting studies at petrochemical facilities as an engineering consultant with ABS Group. This experience includes performing quantitative risk assessments (QRAs) and consequence modeling to evaluate the hazards from vapor cloud explosions, fires and toxic releases. He has also conducted dozens of blower door tests on buildings in petrochemical facilities to evaluate their suitability for personnel as an emergency shelter during a toxic/flammable release. Kevin holds a B.S. in Mechanical Engineering from the University of Texas at San Antonio.

Chris LeBoeuf, Director, ABS Group

William (Chris) LeBoeuf is a licensed professional engineer in multiple states with over 18 years' professional experience as a structural engineering consultant in the Extreme Loads and Structural Risk division at ABS Group. His specialty expertise includes dynamic analysis and design of structures and equipment to mitigate hazards from extreme loading events, to include vapor cloud explosions, jet fires and bursting pressure vessels. Chris works extensively with industry explosion safety criteria documents such as NFPA 68; ASCE Design of Blast Resistant Buildings in Petro-Chemical Facilities; CCPS and AIChE Guidelines for Evaluating the Characteristics of Vapor Cloud Explosions, Flash Fires, and BLEVEs; and similar criteria documents. He has performed more than 50 site surveys to collect data on over 500 buildings. He has worked closely with facility owners, architects and contractors to implement upgrades from conceptual design through building commissioning. In addition, Chris has performed dynamic FEAs for a variety of related issues for petrochemical clients. He has used state-of-the-art finite element codes to analyze structures, structural components, facilities and equipment (e.g. storage tanks, blast chamber, pipe failure) for nonlinear response when subjected to adverse loading conditions and for assessment of conditional performance. Chris is a principal instructor for multiple short courses dedicated to understanding explosion effects and dynamic structural analysis, including "Facility Siting and Consequence Modeling - API 752/753."

About ABS Group

ABS Group of Companies, Inc. (, through its operating subsidiaries, provides data-driven risk and reliability solutions and technical services that help clients confirm the safety, integrity, quality and efficiency of critical assets and operations. Headquartered in Spring, Texas, ABS Group operates with more than 1,000 professionals in over 20 countries serving the marine and offshore, oil, gas and chemical, government and industrial sectors. ABS Group is a subsidiary of ABS, one of the world's leading marine and offshore classification societies.

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