EN ISO 11612 vs EN ISO 11611: Heat, Flame and Welding Protection
The short answer
EN ISO 11611 protects welders: it covers spatter, molten metal and brief contact with flame during welding. EN ISO 11612 protects workers exposed to heat in general — convective, radiant, molten aluminium or iron splash — and its codes (A1, A2, B1–B3, C1–C4, D1–D3, E1–E3, F1–F3) tell you which specific hazards the garment passed. A welding jacket is usually EN ISO 11611; a furnace or foundry garment is usually EN ISO 11612.
If a customer asks for "FR clothing", that is not a specification. The hazard decides which of these two standards applies.
Last updated: September 2026.
Key takeaways
- 11611 is welding-specific, including spatter and molten metal droplets.
- 11612 is heat in general, with letter codes for each hazard type.
- Read the codes on the garment, not just the standard number.
- Both are distinct from arc flash (ASTM F1506) and from flash fire (NFPA 2112).
- A garment can carry several standards, and dual certification is normal in heavy industry.
1. Standard vs use case vs purchasing notes
| Standard | What it covers | Typical use case | What to check when buying |
|---|---|---|---|
| EN ISO 11611 | Welding and allied processes: spatter, molten metal, brief flame contact | Welders, welding assistants, maintenance welding | Class 1 or 2, plus the A1/A2 limited flame spread code |
| EN ISO 11612 | Heat and flame protection in general industry | Foundries, furnaces, smelters, glass, cement | The full code set: A, B, C, D, E, F codes relevant to the hazard |
| ASTM F1506 | Arc-rated clothing | Electrical work | Arc rating in cal/cm² |
| NFPA 2112 | Flash-fire-resistant clothing | Oil and gas, petrochemical | Garment-level certification |
2. What the EN ISO 11612 codes mean
| Code | Hazard tested | Typical value printed |
|---|---|---|
| A1 / A2 | Limited flame spread, surface or edge ignition | Pass or fail |
| B1–B3 | Convective heat | Level 1 to 3 |
| C1–C4 | Radiant heat | Level 1 to 4 |
| D1–D3 | Molten aluminium splash | Level 1 to 3 |
| E1–E3 | Molten iron splash | Level 1 to 3 |
| F1–F3 | Contact heat | Level 1 to 3 |
A foundry garment might read "EN ISO 11612 A1 B1 C1 E3", which tells you exactly which hazards it survived. A garment marked only "EN ISO 11612" without codes is not a useful specification.
3. What to specify on a purchase order
| Item | Specification to write | Why |
|---|---|---|
| Standard and codes | "EN ISO 11612 A1 B1 C1 E3" or "EN ISO 11611 Class 2 A1" | Ambiguity here causes returns and safety incidents |
| Fabric | Inherent or treated FR, with the mill certificate | Determines wash life and performance |
| Weight | GSM range | Heavier fabric adds protection and heat stress |
| Reflective tape | FR-certified tape where hi-vis is also required | Standard tape can melt |
| Laundry | Industrial laundry performance if rented | May require EN ISO 15797 testing |
| Marking | Codes printed on the garment label | Required for site inspection |
4. Frequently asked questions
What is the difference between EN ISO 11611 and EN ISO 11612?
11611 is for welding and similar processes, covering spatter and molten metal droplets. 11612 covers heat in general industry and uses letter codes to show which hazards, such as radiant or convective heat, the garment passed.
Can a welding jacket be used in a foundry?
Only if it is certified to EN ISO 11612 with the codes the foundry hazard requires, such as molten metal splash. Welding certification alone does not cover those hazards.
What does class 1 or class 2 mean in EN ISO 11611?
Class 1 is for lighter welding duties and Class 2 for heavier work with more spatter. The class reflects the test severity rather than the fabric weight alone.
Do these standards cover arc flash?
No. Arc-flash protection is measured under ASTM F1506 in cal/cm². Garments can be certified to both, and utilities usually specify arc-rated clothing.
Is treated FR cotton enough for welding?
It can be, provided the finished garment is certified to EN ISO 11611 with the relevant codes. Treated fabric requires correct laundering to keep its performance.
What should I ask the factory for?
The garment-level test report with the standard and codes named, plus the fabric certificate. For hi-vis FR garments, add the reflective tape certificate.
Get the right heat and welding standard quoted
Tell us the process and the hazard, and we will quote the correct standard and code set with the garment test report and fabric certificate named in the quotation.
