Flash Point Risk Check Calculator

Work out flash point risk check instantly with clear inputs, formula shown and shareable results.

About Flash Point Risk Check Calculator

Flash point is the lowest temperature at which a liquid gives off enough vapour to form an ignitable mixture. Once the liquid is at or above its flash point a flammable atmosphere exists above the surface, so both ambient and process temperatures must be compared against it. Handling at least 10 °C below flash point is normal good practice.

Formula

Risk margin

Margin = flash point - handling temperature; a negative margin means flammable vapour is present

Worked example

With the default values below, Flash Point Risk Check Calculator returns Margin between process and flash point of -22.0. Change any input above and every figure here is recalculated in your browser.

Inputs used

Flash point of the liquidaccepts -60–300 °C: 23 °C
Ambient temperatureaccepts -40–80 °C: 35 °C
Process or handling temperatureaccepts -40–400 °C: 45 °C

Results

Margin between process and flash point: -22.0 °C
Flammability classification: Flammable — flash point 23 to 60 °C
Ambient condition assessment: Ambient temperature is at or above flash point — flammable vapour present
Process condition assessment: Process temperature is at or above flash point — ignition sources must be eliminated

Step by step

1Values used
2Risk margin
3Margin between process and flash point= -22.0 °C
4Flammability classification= Flammable — flash point 23 to 60 °C
5Ambient condition assessment= Ambient temperature is at or above flash point — flammable vapour present
6Process condition assessment= Process temperature is at or above flash point — ignition sources must be eliminated

Assumptions and limits

The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 1 decimal place, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
Preliminary estimate only. Flammable liquid handling, storage and area classification must follow the applicable regulations and a competent person's assessment.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Preliminary estimate only. Flammable liquid handling, storage and area classification must follow the applicable regulations and a competent person's assessment.

Frequently Asked Questions

How is the Flash Point Risk Check figure worked out?

Margin = flash point - handling temperature; a negative margin means flammable vapour is present. Flash point is the lowest temperature at which a liquid gives off enough vapour to form an ignitable mixture.

Is a high flash point liquid safe?

Not if it is heated or misted. A fine spray or a soaked lagging can ignite far below the bulk flash point, which is why hot oil systems are a serious fire risk despite high flash points.

What values do I need to enter?

This calculator takes 3 inputs: Flash point of the liquid, Ambient temperature, Process or handling temperature. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.