ISO 11612
Protective clothing against heat and flame
Supersedes EN 531:1995
The fabric has been tested by EN ISO 11612:2008 standards for a number of qualities including:
•HEAT RESISTANCE,
•LIMITED FLAME SPREAD,
•HEAT TRANSFER
- This standards replaces EN 531:1995, but please note that the protective garments which have an EN 531 certification remain valid.
- The standards specifies the performance requirements for garments which protect the body from heat and flame (except the hands).
- The standard is not applicable for fire fighters (EN 469) and welders (EN 470 – EN ISO 11611).
ISO 11612:2008 specifies performance requirements for garments made from flexible materials, which are designed to protect the wearer’s body, except the hands, from heat and/or flame. For protection of the wearer’s head and feet, the only items of protective clothing falling within the scope of this International Standard are gaiters, hoods and overboots. However, concerning hoods, requirements for visors and respiratory equipment are not given.
The performance requirements set out in ISO 11612:2008 are applicable to garments which could be worn for a wide range of end uses, where there is a need for clothing with limited flame spread properties and where the user can be exposed to radiant or convective or contact heat or to molten metal splashes.
I. ISO 15025- Code letter A (part of ISO 11612)
- А – indicates that the garment meets the requirements for limited flame spread.
- This 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). This test is also used for EN 531A.
- The application of a flame can take place in two ways:
- А1 — surface ignition method
- А2 — edge ignition method
- Requirements for parameter A
- in procedure A (leads to Class A1), the flame is applied horizontally (similarly to EN 470-1 and EN 531)
- in procedure B (leads to Class A2), the flame is applied laterally.
- Minimum requirement, fabric combination conforms to the old EN 533 index 3
II. ISO 9151 – Code letter B (part of ISO 11612)
- B – indicates that the garment provides protection against convective heat. (Insulation against convective heat)
- Convective heat: determination of the heat transmission when exposed to flames.
- The sample is held above the flame and the rise in temperature on the topside of the sample is measured with a calorimeter. Subsequently, the length of time the sample can remain exposed before its temperature rises by 24 °C is determined.
- Requirements for parameter B
- B1:4 < 10 seconds
- B2:10 < 20 seconds
- B3:>21 seconds
| Code letter B indicates that the fabric provides protection against convective heat. | Requirements for parameter B | The highest level of protection against convective heat is Level 3. |
| B1 | 4 < 10 seconds | Level 1 (Basic protection) |
| B2 | 10 < 20 seconds | Level 2 (Middle protection) |
| B3 | > 20 seconds | Level 3 (High protection) |
III. ISO 6942 – Code letter C (part of ISO 11612)
- C – indicates that the garment provides protection against radiant heat (infrared rays).
- 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 length of time the sample can remain exposed before its temperature rises by 240C is measured. The test procedure is the same as ISO 11611, but the classification is different:
- Requirements for parameter C:
- C1: 7 < 20 seconds
- C2: 20 < 50 seconds
- C3: 50 < 95 seconds
- C4: 95 seconds and longer
| Code letter C indicates that the fabric provides protection against convective heat. | Requirements for parameter C | The highest level of protection against radiant heat is Level 4. |
| C1 | 7 < 20 seconds | Level 1 (Basic protection) |
| C2 | 20 < 50 seconds | Level 2 (Middle protection) |
| C3 | 50 < 95 seconds | Level 3 (High protection) |
| C4 | 95 seconds and longer | Level 4 (Highest protection) |
IV. ISO 9185 – Code letter D and E (part of ISO 11612)
- D – indicates that the garment provides protection against spatters of molten metal (molten aluminum)
- Determining the level of protection against spatters of molten metal.
- 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.
- The quantity of molten metal which deforms the membrane is determined.
- Requirements for parameter D (The classification for molten aluminium):
- D1: 100 < 200 grams
- D2: 200 <350 grams
- D3: 350 grams and more
| Code letter D indicates that the fabric provides protection against spatters of molten aluminum | Requirements for parameter D | The highest level of protection against spatters of molten aluminum is Level 3 |
| D1 | 100 < 200 grams | Level 1 (Basic protection) |
| D2 | 200 < 350 grams | Level 2 (Middle protection) |
| D3 | 350 grams and more | Level 3 (High protection) |
- E – indicates that the garment provides protection against spatters of molten metal (molten iron)
- Determining the level of protection against spatters of molten metal.
- 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.
- The quantity of molten metal which deforms the membrane is determined.
- Requirements for parameter E (The classification for molten iron):
- E1: 60 < 120 grams
- E2: 120 < 200 grams
- E3: 200 grams and more
| Code letter E indicates that the fabric provides protection against spatters of molten iron | Requirements for parameter E | The highest level of protection against spatters of molten iron is Level 3 |
| E1 | 60 < 120 grams | Level 1 (Basic protection) |
| E2 | 120 < 200 grams | Level 2 (Middle protection) |
| E3 | 200 grams and more | Level 3 (High protection) |
Protective clothing – Clothing to protect against heat and flame
Here you can see all the required tests for ISO 11612 given in a table:
| Fabric Tests | Code letter | Test Method | REM | |
| 1. | 5.2 Pretreatment | ISO 6330: 2000 | See Note | |
| 2. | 6.2.1 Heat resistance (180°C) | ISO 17493: 2000 | 94 | |
| 3. | 6.2.2 Heat resistance (260°C) | ISO 17493: 2000 | 94 | |
| 4. | 6.3.2 Flame spread – face ignition (A1) | A1 | ISO 15025: 2000 (A) | 120 |
| 5. | 6.3.3 Flame spread – edge ignition (A2) | A2 | ISO 15025: 2000 (B) | 120 |
| 6. | 6.4 Dimensional change | ISO 5077: 2007 | 37 | |
| 7. | 6.5.1 Tensile strength | ISO 13934-1: 1999 | 66 | |
| 8. | 6.5.2 Tear strength | ISO 13937-2: 2000 | 66 | |
| 9. | 6.9.2 pH – value | ISO 3071:2005 | 45 | |
| 10. | 7.2 Convective heat (B) | B | ISO 9151: 1995 | 116 |
| 11. | 7.3 Radiant heat (C) | C | ISO 6942: 2002 | 116 |
| 12. | 7.4 Molten aluminium splash (D) | D | ISO 9185: 2007 | 366 |
| 13. | 7.5 Molten iron splash (E) | E | ISO 9185: 2007 | 432 |
| 14. | 7.6 Contact heat (F) | F | ISO 12127: 1996 | 116 |
Note: The cleaning pre-treatment cost depends on the type of cleaning and the number of cycles specified by the manufacturer. BTTG Fire Technology Services can undertake cleaning to ISO 6330; the cost of 5 wash/dry cycles, for example, is £120 (+VAT). If dry-cleaning to ISO 3175 or “industrial” washing to ISO 15797 is required this will be subcontracted (price on application).
V. ISO 12127 – Code letter F (part of ISO 11612)
- F – indicates that the garment provides protection against contact heat.
- Exposure to contact heat. In this test, a fabric sample is exposed to contact heat.
- Requirements for parameter F:
- F1: 5 < 10 seconds
- F2: 10 < 15 seconds
- F3: 15 seconds and longer
| Code letter F indicates that the fabric provides protection against contact heat | Requirements for parameter F | The highest level of protection against radiant heat is Level 4. |
| F1 | 5 < 10 seconds | Level 1 (Basic protection) |
| F2 | 10 < 15 seconds | Level 2 (Middle protection) |
| F3 | 15 seconds and longer | Level 3 (High protection) |