Calculators › Consequence Modeling
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Consequence Modeling Toolkit

Jet Fire · Pool Fire · VCE · BLEVE · Toxic Dispersion

Consequence Modeling Calculator
Quantifies potential impacts of fire, explosion, and toxic release scenarios using industry-standard methods. Provides thermal radiation distances, overpressure zones, and toxic dispersion modeling for risk assessment, HCA identification, and emergency planning.
Select Scenario Type:

Release Parameters

lb/s
s
psig
°F

Material Properties

g/mol
kJ/kg
Common values: CH₄: MW=16, k=1.31 | C₃H₈: MW=44, k=1.13 | H₂S: MW=34, k=1.32

📚 Learn the Theory

Comprehensive guide to dispersion modeling, thermal radiation, overpressure, and HCA determination per 49 CFR 192.

Read Engineering Guide →

Formula Reference

Jet Fire Thermal Radiation
q = τ × Qrad / (4πR²)
q = Heat flux (kW/m²)
τ = Atmospheric transmissivity
Qrad = Radiated power (kW)
R = Distance from flame (m)

Thermal Radiation Criteria

kW/m²Effect
1.6Safe indefinite exposure
5.0Pain threshold (20s)
12.51% lethality (1 min)
37.5100% lethality (<1 min)

Overpressure Criteria

psiDamage
0.3Glass breakage
1.0Minor structural
3.0Heavy damage
5.0Building collapse

Standards & References

  • API 521
    Pressure-Relieving Systems (2020)
  • CCPS Guidelines
    Chemical Process QRA (2000)
  • TNO Yellow Book
    Physical Effects Methods (2005)
  • 49 CFR 192.903
    HCA Identification (PIR formula)
  • EPA RMP
    Offsite Consequence Analysis

Important Notes

  • Results are screening-level estimates for preliminary analysis.
  • Use validated software (PHAST, ALOHA, CANARY) for detailed studies.
  • Stability class F with 2 m/s wind is typical worst-case for HCA analysis.
  • Heavy gases (SG > 1) require dense gas models like DEGADIS.
  • Congestion/confinement significantly affects VCE severity.

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