SLAB is ideal for determining toxic endpoint distances and distances to lower flammability limits (LFLs) for certain toxic and flammable chemicals in accordance with EPA’s Risk Management Program (RMP) requirements.
SLAB can be used to model continuous, finite, and instantaneous releases from evaporating pool, elevated horizontal or vertical jets, and instantaneous area or volume sources. Except for the evaporating pool sources, which are assumed to be all vapor, the remaining sources may be either pure vapor or a mixture of vapor and liquid droplets (aerosol). For each scenario, a user-specified averaging time is required.
SLAB was developed specifically to model heavier-than-air gaseous (dense gas) releases. A cloud from a dense gas release behaves very differently than a plume from a lighter-than-air release. Since the gas is heavier than air, the cloud characteristics are primarily gravity-driven.
Negative buoyancy and stable density stratification are among the factors that prevent the application of a Gaussian dispersion model from accurately simulating a dense gas release.
BREEZE SLAB can be applied to a number of scenario types including:
- Emergency response planning
- Industrial chemicals, highly-toxic chemicals
- Applies to a wide range of accidental release scenarios and report writing
Release Types
SLAB can model a number of release scenarios, including:
| Release Type |
Duration |
Evaporating Pool
|
• Continuous
• Finite
|
Horizontal Jet
|
• Continuous
• Finite
|
Vertical Jet / Stack
|
• Continuous
• Finite
|
Instantaneous
|
• Instantaneous
|
Liquid Spill
|
• Continuous
• Finite
• Instantaneous
|
Typical Users
The typical BREEZE SLAB user includes:
- Plant managers
- Emergency planner
- Process analyst
- PR staff
- Plant-level EH&S
- Students and researchers