Image of “Flaming” cocktails is by Nik Frey (niksan).

What is Flashpoint?

Flashpoint means the lowest temperature of a liquid at which its vapour forms an ignitable mixture with air.

Flashpoint gives a measure of the risk of formation of explosive or ignitable mixtures when the liquid escapes from its packing.

A flammable liquid cannot be ignited so long as its temperature remains below the flashpoint.

How Flashpoint is tested?

A specified quantity of the liquid is introduced into a receptacle at a temperature well below the flashpoint to be expected, then slowly heated; periodically, a small flame is brought near to the surface of the liquid. The flashpoint is the lowest temperature at which a “flash” is observed.

The test methods can be divided into two groups, depending on the use in an apparatus of an open receptacle (open-cup methods) or a closed one which is only opened to admit the flame (closed-cup methods). As a rule, the flashpoints found in an open-cup test are a few degrees higher than in a closed-cup test.

How Flashpoint changes the rules to load dangerous goods on board ships?

SOLAS Regulation II-2/19.4 requires flag state administration to provide the ship with a document as evidence of compliance of construction and equipment with the requirements of regulation II-2/19 of SOLAS 1974 Convention. This document of compliance (DOC) certifies which cargo hold is permitted to carry which class of dangerous goods.

For cargoes with flashpoint below or above 23 Deg Celsius there is difference in permission and this is grouped  as below.

• Class 3 FP < 23°C
• Class 3 FP ≥ 23°C to ≤ 60°C
• Class 6.1 liquids FP < 23°C
• Class 6.1 liquids FP ≥ 23°C to ≤ 60°C
• Class 8 liquids FP < 23°C
• Class 8 liquids FP ≥ 23°C to ≤ 60°C

Class 4.3 Liquids having a Flashpoint less than 23°C under deck is prohibited by IMDG Code,

Below a sample section of DOCUMENT OF COMPLIANCE permitting dangerous goods having flashpoint below 60 Deg C in packaged form

Declaration of Flashpoint

Section 5.4.1.4.3.6 of IMDG Code states

“If the dangerous goods to be transported have a flashpoint of 60°C or below (in °C closed-cup (c.c.)), the minimum flashpoint shall be indicated.”

As per this requirement all dangerous goods belonging to below hazardous classes must have flashpoint in dangerous goods declaration

• Class 3
• Class 4.3 with subsidiary risk class 3
• Class 6.1 liquids with subsidiary risk class 3
• Class 8 liquids with subsidiary risk class 3