When a buyer tells us their crew faces flash fire, arc flash or welding, the conversation moves immediately from fabric to certification. The two standards that govern that conversation test different things, document differently, and carry different labels — and assuming they are interchangeable is the most expensive mistake we see in FR sourcing.
What the two standards actually certify
NFPA 2112 certifies protection against short-duration flash fire — it is a pass/fail material and garment standard built around a full-garment thermal manikin test that predicts body burn. EN ISO 11612 is broader: it certifies protection against heat and flame across several hazard types, each reported as a coded performance level rather than a single pass/fail. A garment can carry both, but you should know which hazard your crew faces before demanding either.
NFPA 2112: the flash-fire pass/fail
NFPA 2112 is the standard US oil, gas and petrochemical safety programs reference (paired with NFPA 2113 for selection and use). Certification requires third-party testing of flammability after 100 industrial wash cycles, plus heat resistance, thermal shrinkage and the manikin burn test. The number buyers most often ask about — Arc Rating / HRC — actually comes from a different standard (NFPA 70E / ASTM F1959), so an NFPA 2112 label alone tells you nothing about arc protection. If your hazard includes arc flash, demand both data sets.
EN ISO 11612: the A-F code letters
EN ISO 11612 reports performance as letter codes, and decoding them is the buyer's job:
- A1 / A2 — limited flame spread (A1 = surface ignition, A2 = edge ignition)
- B — convective heat (level 1-3)
- C — radiant heat (level 1-4)
- D — molten aluminium splash (level 1-3)
- E — molten iron splash (level 1-3)
- F — contact heat (level 1-3)
A welding garment and a foundry garment may both be 'EN ISO 11612 certified' yet have completely different code profiles. Always ask for the full code string, not just the standard number.
Inherent vs treated — and why wash retention matters
FR fabric comes in two families. Inherent FR — Meta-Aramid (Nomex-equivalent) or modacrylic blends — has flame resistance built into the fibre, so it cannot wash out. Treated FR is a chemical finish on cotton or cotton-rich fabric; it is cheaper, but its protection degrades if laundered incorrectly. Both standards require testing after repeated wash cycles for exactly this reason. If a quote looks unusually cheap, confirm whether it is inherent or treated, and demand the post-wash test report — not the virgin-fabric one.
| Dimension | NFPA 2112 (US) | EN ISO 11612 (EU) |
|---|---|---|
| Result format | Pass/fail at garment level | Coded levels A-F |
| Core test | Thermal manikin body-burn | Heat & flame property panel |
| Arc rating included? | No — see NFPA 70E / ASTM F1959 | No — see IEC 61482 for arc |
| Wash conditioning | 100 industrial cycles | Min. 5 cycles, or as specified |
| Typical use | Oil, gas, petrochemical flash fire | Welding, foundry, general heat |
The documents to demand before you pay
- A third-party test report — not a self-declaration — naming the accredited lab
- The report tied to your fabric and colour, post-wash, not a generic virgin sample
- For EN ISO 11612, the complete code string (e.g. A1 B1 C1 E2 F1)
- For arc-flash crews, a separate arc rating (ATPV/EBT) report
- Garment-level certification, not just fabric — trims, thread and closures must be FR too
Speccing an FR program?
Tell us the hazard — flash fire, arc flash, welding or foundry — and we will quote inherent or treated FR against the right standard, with post-wash third-party test reports and the full EN ISO 11612 code string.
Request an FR quote →