// multi-utility computation suite · offline · instant · precise
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sci.HAZOP-consequence-toxic-IDLH Calculator
Calculates centreline concentration from a toxic release at downwind distance x using Gaussian plume dispersion and compares to IDLH. Dispersion parameters σy and σz depend on Pasquill-Gifford stability class — Class A (unstable, sunny) gives fastest dilution; Class F (stable, night) gives slowest.
Inputs
Release Rate Kg S
Amount per unit of time or per unit quantity. Check the denominator before interpreting.
Mw G Mol
Body or object weight. For health calculators, usually in kg or lbs.
Idlh Ppm
Amount of solute per unit volume. Higher concentration = more solute dissolved.
U M S
Rate of movement. 1 m/s = 3.6 km/h = 2.237 mph.
Sigma Y M
Reference formula or conversion factor shown for context.
Sigma Z M
Reference formula or conversion factor shown for context.
Results
centreline concentration at x (ppm)
The proportional relationship between two quantities.
IDLH threshold (ppm)
Reference formula or conversion factor shown for context.
exceeds IDLH?
Reference formula or conversion factor shown for context.
Gaussian ground-level C = Q/(πσyσzu)
The measured or computed level on the applicable scale.