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.

Frequently Asked Questions

What does the Consequence Modeling Calculator analyze?

It models potential consequences of accidental releases including jet fire, pool fire, VCE (vapor cloud explosion), BLEVE, and toxic dispersion.

What standards does this consequence modeling tool follow?

It follows API 521, CCPS guidelines, TNO Yellow Book methods, and 49 CFR 192 for consequence analysis.

What types of fire scenarios can this calculator model?

The calculator models jet fire, pool fire, VCE, and BLEVE scenarios, calculating thermal radiation and overpressure effects.

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