EN ISO 11611

Within EN ISO 11611 there are a series of tests – the most important of which are described in ISO 6942, ISO 9150, ISO 15025 and EN 1149-2. ISO 11611 has two classes – if the fabric passes all the tests, it is designated as Class 1 and if the fabric receives a Class 2 rating for the ISO 6942 and ISO 9150 tests, it is designated as Class 2.

Class 1 – Lower Hazard Welding Applications
Class 2 – Higher Hazard Welding Applications

ISO 6942: This is a test method for assessing fabrics and fabric combinations exposed to radiant heat. In this test, a fabric sample is exposed to radiant heat (infrared rays). The temperature on the reverse (unexposed) side of the sample is registered using a calorimeter. Subsequently, the length of time the sample can remain exposed before its temperature rises by 24°C is measured.

This test is also used for EN 531C and has two different classes as follows:

Class 1 temperature increase occurs after ≥ 7 seconds
Class 2 temperature increase occurs after ≥ 16 seconds.

ISO 9150: Determining the behaviour of fabrics when exposed to small spatters of molten metal. In this test, droplets of molten metal are spattered on a vertically suspended fabric sample. The number of droplets it takes to cause an increase in temperature of 40°C on the reverse side of the sample is determined. This test also has two classes as follows:

Class 1 ≥ 15 droplets of molten metal
Class 2 ≥ 25 droplets of molten metal.

ISO 15025: The test method for limited flame spread. The test consists of applying a flame to a fabric sample for 10 seconds. To pass the test, the after flame & smoulder times and formation of holes must be within the tolerances (set in the standard). The application of a flame can take place in two ways:
in procedure A (leads to Class A1), the flame is applied horizontally
in procedure B (leads to Class A2), the flame is applied laterally.

EN 1149-2: This is a test method for measuring the electrical resistance of a fabric sample and determining whether an electrical charge passes through the sample from the outside to the inside. For further information on this EN Standard please refer to the EN1149 section.

Criteria for choice on the basis of the type of process

CLASS 1

Manual welding operations during which small amounts of spatter or droplets of molten metal are formed
– Gas welding
– TIG welding
– MIG welding
– Micro plasma welding
– Soldering brass
– Spot welding
– Shielded electrode MMA welding

CLASS 2

Manual welding operations during which large amounts of spatter or droplets of molten metal are formed, e.g.:
– MMA welding (using alkaline or cellulose electrodes)
– MAG welding (with CO2 or mixed gasses)
– MIG (high-voltage) welding
– Flux-cored arc welding
– Plasma cutting
– Gouging
– Oxygen cutting
– Thermal spraying

Criteria for choice on the basis of the type of work

CLASS 1

Operating machines, e.g.
– Oxygen cutting machines
– Plasma cutting machines
– Resistance pressure welding machines
– Thermal spraying
– Welding tables

CLASS 2

Operating machines, e.g.:
– In enclosed spaces
– When welding/cutting operations require reaching above head height or take place in comparable difficult positions