Protective gloves for welders

There are a number of hazards associated with traditional metal welding. European standard EN 12477:2001+A1:2005 Protective gloves for welders has been developed which specifies minimum performance requirements and test methods appropriate to protective gloves used in manual metal welding, cutting and allied processes.

EN 12477:2001+A1:2005 requires performance to be determined against small splashes of molten metal, burning behaviour, convective (Type A only) and contact heat. Glove materials suitable for EN 12477:2001+A1:2005 applications also have to provide a degree of physical protection against typical occupational risks such as cutting, tearing, abrasion and puncture and also provide a minimum electrical resistance up to 100 volts dc for arc welding (not to be confused with protection against electric shock which is the subject of EN 60903). The standard was amended in 2005 (amendment 1) and has been updated to include EN 420:2003 gloves, as well as adding optional requirements for gloves intended to be used for arc welding, and for EN 1149-2:1997 – ‘Electrostatic properties’.

Welders’ gloves are categorised according to their performance:

• Type A: lower dexterity (with higher performance for physical characteristics such as abrasion, tear, puncture and convective heat resistance) recommended for all welding processes except TIG* welding
• Type B: higher dexterity (with lower physical performance) recommended for TIG welding.

The two types of gloves are subject to different minimum performance requirements under EN 388:1994, EN 407:1994 and EN 420:2003.

Welding gloves are subjected to the four physical tests detailed in EN 388 to determine their mechanical strength properties. Additionally they are tested for resistance to a small ignition source, using a gas burner as defined in ISO 6941.

Convective heat transmission through gloves is assessed using equipment detailed in EN 367:1992 Method of determining heat transmission on exposure to flame and enables materials to be ranked by calculation of a heat transfer index which is an indication of the relative protection under the specified test conditions. This clause is applicable to Type A gloves only. Hot contact tests determine protection against heat transmission.

The principle of the contact heat test is to apply a heated cylinder incorporating a thermal sensor to a piece of the material under test/evaluation and to monitor the temperature rise of another sensor placed behind the sample.

Assessment of heat transfer when products are subjected to small quantities of molten metal (as produced by a welders torch, for example), is carried out using a rig incorporating an oxyacetylene torch to project molten metal drops onto a test specimen. The ability for the drops to ‘run off’ the material, rather than stick, is critical to good performance.

Dexterity tests are relatively simple, with the dexterity level being determined by the smallest of different diameter pins that can be picked up while wearing the gloves.

In addition to the mandatory tests listed above, the standard now details an optional test intended for arc welding applications. Using EN 1149-2, electrical resistance is measured by attaching electrodes to either side of the material and applying a dc voltage between them. The resulting electrical resistance is then measured.

Many welders’ gloves are made from leather and therefore these also need to be assessed for pH and chrome VI content (using EN 420:2003).

Other European restricted substances legislation – for example, azo dyes – will also apply if certifying for the European market.

* Tungsten inert gas (TIG) welding produces a small intense arc via a pointed tungsten electrode in an inert atmosphere of argon or helium and is used for high quality and precision welding, particularly of aluminium.

Further information on SATRA’s PPE certification and testing services is available at www.satra.com/ppe