Standard: EN 531 Clothing to protect against Heat and Flames
European norm EN 531: replaced by EN ISO 11612
EN 531:1995 Protective clothing for industrial workers exposed to heat (with the exception of firefighters and welders).
EN 531 specifies requirements for clothing designed to protect the wearer against heat and flames (not including firefighting clothing).
This standard has now been replaced by EN ISO 11612. EN 531 can still be used in previously certified clothing. However, new certification can only take place in accordance with ISO 11612
The contents of this standard
This standard’s pictogram is a flame placed above EN 531 followed by a series of letters and numbers. This standard has 5 different tests, the results of which are given as letters A, B, C, D and/or E. The meaning of the letters is explained below. For istance: 'EN 531:1995 A B2 C1'.
Different tests, codes
531A (EN 532)
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 hole formation must be within the tolerances set in the standard.
531B (EN 367)
Test method for convective heat during exposure to flames. In this test, a fabric sample is exposed to heat. The sample is held over a flame and the rise in temperature on the topside is measured using a calorimeter. Subsequently, the length of time the sample can remain exposed before its temperature rises by 24 °C is determined.
Class B1: 3 to 6 seconds
Class B2: 7 to 12 seconds
Class B3: 13 to 20 seconds
Class B4: 21 to 30 seconds
Class B5: 31 seconds and longer.
531C (EN 366)
Test method: Assessment of fabrics and fabric combinations during exposure 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 time it takes in seconds for the temperature of the fabric to rise sufficiently to cause the onset of second-degree burns is determined and denoted in 4 classes.
Class C1: 8 to 30 seconds
Class C2: 30 to 90 seconds
Class C3: 90 to 150 seconds
Class C4: 151 seconds and longer.
EN 531D or E (EN 373)
Assessment of the fabric resistance to spatters of molten metal. In this test, a membrane (with similar properties to human skin) is attached to the reverse of the fabric sample. Subsequently, sequentially rising quantities of molten metal (for the D value - molten aluminium and for the E value - molten iron) are splashed on the sample and the quantity at which the membrane deforms sufficiently to cause second-degree burns is determined and denoted in 6 classes.
Class D1: 100 to 200 grams
Class D2: 201 to 350 grams
Class D3: 351 gram and more.
Class E1: 60 to 120 grams
Class E2: 121 to 200 grams
Class E3: 201 gram and more.
The requirements set in this standard
- The respective clothing must always comply with EN 531A, plus 1 of the other codes (B to E). The label must indicate the test values of the constituent fabric (combination)
- Clothing must meet the requirements stipulated in EN 340
- Model requirements only apply in respect of D and/or E codes
- Trouser-legs must be long and wide enough to overlap the top of the wearer's footwear
- Trouser-legs may not have any raised seams
- Exterior pockets must have a flap that is at least 10 mm wider than the actual pocket on both sides
- Metal fastenings must be covered on the outside
- Pleats, etc. must be avoided
- It must be possible to remove the clothing quickly in an emergency.