HazardBench

Licence: —

Scenario setup Define the source, environment and risk assumptions. Results update only when you run the calculation.

1 — Chemical

Custom material / add a substance

Enter documented properties in the units shown. Saved materials stay in this browser. Vapour pressure and diffusivity use the standard model correlations. A user threshold is not an AEGL or IDLH value.

Saved custom materials

Material properties are fed into the calculation automatically once a substance is selected.

2 — Scenario

Consequence model Release type

3 — Release conditions

Vessel pressure (barg)

Material temperature (°C)

Downstream pressure (bara)

Compressibility factor Z

Gas inventory model

Vessel gas volume (m³)

Liquid inventory model

Liquid surface above opening (m)

Tank cross-sectional area (m²)

Dynamic viscosity (mPa·s, optional)

Two-phase aerosol uncertainty bound

Opening geometry

Cd selection

Opening diameter (mm)

Chosen discharge coefficient Cd

Cd is selected from geometry and flow regime. Contraction and line friction are recorded separately.

Source height (m)

Jet orientation

Jet-fire radiant fraction (optional)

Leave blank to use the catalogue estimate (status Estimated). Enter a sourced value from 0.05 to 0.5 to override it; the result records which was used.

Pool-fire surface emissive power, kW/m² (optional)

Leave blank to use the catalogue estimate (status Estimated). Enter a sourced value from 10 to 350 kW/m² to override it.

Direct rate (kg/s)

Inventory mass (kg)

Release duration (s)

Bund area (m²)

Include plume rise (stack / vertical vent)

4 — Atmospheric conditions

Observed wind used to derive stability (m/s)

Wind measurement height (m)

Wind direction (° from north)

Air temperature (°C)

Relative humidity (%)

Surface roughness / environment

Stability selection

Solar period

Solar radiation (W/m²)

Cloud cover (oktas, 0–8)

Reference wind speed for each stability class (m/s)

Class A

Class B

Class C

Class D

Class E

Class F

Each selected class uses only its own wind. Calm values below 0.5 m/s are not computed; near-calm values below 1 m/s are explicitly limited.

Mixing-layer height (m)

Averaging time (s)

Pasquill–Gifford stability classes (multiple)

Manual mode checks selected classes against the entered meteorology; derived mode runs the compatible class or adjacent boundary classes.

5 — Receptor and monitoring

Receptor height (m)

Calculation range (m)

Monitoring distances (m, comma separated)

Population density (people/km²)

Scenario frequency (1/yr)

Population present (%)

Unprotected/outdoor population (%)

Sheltered fatality factor (%)

These analyst-defined factors convert census density into the effective exposed population used by the societal-risk calculation.

6 — Quantitative risk (QRA)

Release environment Degree of congestion

Immediate ignition

Delayed ignition

Explosion probability

Wind rose

Frequency of wind blowing from each direction, in per cent. The total is normalised automatically.

Consequence analysis workspace

Review model outputs, spatial effects and risk evidence.

Material—

Scenario—

Release—

Conditions—

Set the inputs and press RUN.

Engineering charts are drawn here after a run.

Contours and the map appear here after a run.

Probit and risk are computed here after a run.

No result has been saved for comparison yet.

PDF and Excel output is produced here after a run.