Combustibility

Definition

These test checks whether and to what extent a fire started by external ignition can spread in deposited dust.

Determination

An attempt is made to ignite the dust sample heaped to form a strip of product about 2 cm wide and 4 cm long at one end with a glowing platinum wire with a temperature of about 1000 °C. The wire is immersed only briefly in the dust sample, so that the latter is not heated. A 5 mm to 20 mm thick ceramic plate is used as a base. In the case of melting substances, a modified combustion test is also carried out on a sample to which 20 % in weight kieselgur has been added. The result frequently indicates obvious combustion behaviour.

The combustibilityis evaluated by the class numbers BZ 1 to BZ 6.

Combustibility	BZ
Does not catch fire	BZ 1
Catches fire briefly and extinguishes rapidly	BZ 2
Local burning or glowing without spread	BZ 3
Spread of a glowing fire	BZ 4
Spread of an open fire	BZ 5
Very rapid combustion	BZ 6

Remark

The values specified in brackets refer to the modified combustion test with melting substances after admixing 20 % by weight kieselgur.

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