BlazeTech Logo CONTACT US

Off-site Consequence Analysis for Fire, Explosion and Dispersion of Hazardous Chemicals

A four-day coordinated course is offered by BlazeTech Corporation:

Day One will cover the basics of Off-site Consequence Analysis (OCA) and their regulatory context. Example OCAs will be carried out for worst-case and alternate scenarios using BlazeTech's computerized version of the EPA OCA Tables Attendees will receive a free copy of this software with registration.

Day Two will cover Advanced Off-site Consequence Analysis.  We will examine alternate scenarios using more realistic modeling methods compared to those that form the basis of the EPA Tables.  These will yield more accurate and often shorter hazard distances than the ones predicted by EPA Tables. For example, accounting for reaction of halogenated compounds with atmospheric moisture may produce cloud lift-off and result in a significant decrease in the hazard distance at ground-level.

Day Three will cover the dispersion hazards from the simultaneous release of a mixture of reacting chemicals in the open atmosphere.  This includes the normal discharge from demilitarization operations (OBOD) and rocket launches as well as accidental releases resulting in conflagrations involving several chemicals or multiple reactions.  We will feature BlazeTech's ADORA software (Atmospheric Dispersion of Reacting Agents). This software is unique in its ability to calculate the products of reactions, i.e., the emission factors from major conflagrations.

Day Four will provide hands-on training for ADORA.

Course Outline

Day One: Basic Off-site Consequence Analysis

Regulatory Issues

  • CAA 112r Requirements and RMP
  • Applicability and Regulated Substances
  • Programs 1, 2 and 3
  • Requirements for OCA Calculations
  • Worst-case Scenario
  • Alternate Release Scenario
  • Regulatory Status of Models

Characterization of Accidental Releases

Major Historical Accidents

  • Fire, Explosion and Dispersion
  • OCA using BlazeTech's Computerized EPA Tables
  • Toxic Gas/Liquid
  • Flammable Gas/Liquid
  • Thermal Radiation
  • Overpressure

Related Issues

  • Toxicity
  • Mitigation Effects
  • Hazard/Risk Analysis

Class Discussion

Day Two: Advanced Off-Site Consequence Analysis

  • Source Term Characterization
  • Dense Cloud and Plume Rise
  • Complex Terrain, Deposition
  • Instantaneous Buoyant Puff Rise
  • Building Effects/Plume Lift Off
  • Plume Modeling with One-step Reaction
  • Averaging time/toxicity
  • Comparison of Available Models


  • Deflagration, Detonation and Transitions
  • Confined Explosion of Gases
  • Unconfined Vapor Cloud Explosions
  • Blast and Overpressure Calculations
  • TNT Equivalent Yields
  • Multi-energy Method
  • Structural Response


  • Pools and jets
  • Vapor Clouds and Flash Fires
  • Fire balls and BLEVEs
  • Thermal Radiation

Class Discussion
Day Three: Dispersion Hazards from Release of Mixtures of Reacting Chemicals

  • Regulatory Context: RCRA and state requirements
  • Open Burn Open Detonation  (OBOD)
  • Rocket Launch and Accidents
  • Industrial Conflagrations
  • Cloud Physics
  • Burn vs. Detonation
  • Fireballs and Stems
  • Above vs. Below Ground Detonation

Cloud chemistry

  • Thermochemical Equilibrium
  • Kinetic Approximations
  • Prediction of Emission Factors

Case Studies Using ADORA

  • Dugway's Bangbox MunitionTests
  • Discharge from Titan IV and Delta Rockets
  • Propane Conflagration involving Chlorine
  • Parametrics to Minimize Off-site Hazards
  • Water Deluge Effects

Class Discussion
Day Four: Hands-on Training for ADORA

Case Studies

Input/Outputs, Databases