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EU A.12: Flammability (contact with water)

This test method can be used to determine whether the reaction of a substance with water or damp air leads to the development of dangerous amounts of gas or gases which may be highly flammable.

Study Design

Course of the test

The test item will be tested according to the step by step sequence described below; if ignition occurs at any step, no further testing is necessary because the substance is regarded as hazardous. If it is known that the test item does not react violently water it will proceeded to step 4.

Step 1:

A small quantity (approx. 2 mm diameter) of the test item will be placed in a petri dish which contains deion. water at 20 °C. A note will be made of whether any gas is evolved and if ignition of the gas occurs.

Step 2:

A filter paper will be floated flat on the surface of deion. water at 20 °C in a petri dish. A small quantity (approx. 2 mm diameter) of the test item will be placed onto the centre of the filter paper. A note will be made of whether any gas is evolved and if ignition of the gas occurs.

Step 3:

The test item will be made into a pile approximately 2 cm high and 3 cm in diameter with an indentation on the top. A few drops of water will be added to the hollow and a note will be made whether any gas is evolved and if ignition of the gas occurs.

Step 4:

The container of the test item will be inspected for any powder < 500 µm (particle size). If the powder constitutes more than 1 % w/w of the total, or if the sample is friable, then the whole of the test item will be ground to a powder before testing. Otherwise the test item will be tested as received.
The test will be performed at room temperature (approximately 20 °C) and atmospheric pressure.
10 to 20 mL of water will be put into the dropping funnel of the apparatus and 10 g of the test item will be put in the conical flask. The volume of gas evolved will be measured by suitable apparatus.
The tap of the dropping funnel will be opened to let the water into the conical flash and a stop watch will be started. The gas evolution will be measured each hour during a seven hour period. If, during this period, the gas evolution is erratic, or if, at the end of this period, the rate of gas evolution is increasing, then measurements will be continued for up to five days. If, at any time of measurement, the rate of gas evolution exceeds 1 litre/kg per hour, the test will be discontinued.

This test will be performed in triplicate.

If the chemical identity of the gas is unknown, the gas will be analyzed. When the gas contains highly flammable components and it is unknown whether the whole mixture is highly flammable, a mixture of the same composition will be prepared and tested according to the method A.11.

Endpoints

The substance is considered hazardous if:

- spontaneous ignition takes place in any step of the test procedure,

or

- there is evolution of flammable gas at a rate greater than 1 litre/kg of the substance per hour.

Guidelines and literature

  • European Economic Community (EEC), EEC Directive 92/69, Annex V, Part A, Methods for the determination of physico-chemical properties, A.12 „Flammability (Contact with Water)“, EEC Publication No. L383, December 1992.