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Flash Point
Flash Point
The Flash Point (or ignition temperature) is the lowest temperature (�C) and at atmospheric pressure (1013 mbar) at which a liquid gives off so much combustible vapor (at of near the liquid surface) that this vapor mixes intensively with air through a flameor spark can be ignited.
Although the definition of the flash point is quite straightforward, its determination encounters so many difficulties in practice thast it has been decided to specify the flash points with reference to the measurement methods used. To the best of our knowlegde, these methods are also presented in DOHSBase.
In transport regulations (UN, ADR, IMDG, IATA) and in GHS and CLP the following limit values are used for classification:
- Category 1: flash point < 23 �C and boiling point < 35 �C
- Category 2: flash point < 23 �C and boiling point > 35 �C
- Category 3: flash point > 23 �C and < 60 �C
Sometimes an extra category for flashpoint < 0 �C is used (derived from the old system below), or for substances with a flash point between 60 and 100 �C (category 4 in GHS).
The values below, stemming from the former European Dangerous Substances Directive (67/548/EC), are partly outdated, although still used by many companies for e.g. storage purposes:
- Flash Point < 21 �C
- Flash Point >21 �C and < 55 �C
- Flash Point > 55 �C and < 100 �C
- Flash Point > 100 �C