If you source cable from China, you have almost certainly seen "WDZ", "WDZA" or "WDZC" on a quotation and wondered whether it is the same thing as the LSZH (low-smoke, zero-halogen) cable your market requires. It is not the same — and the gap matters, because it is the difference between a compliant installation and a rejected one. This guide decodes the Chinese WDZ code system, shows which international tests it actually corresponds to, and — most importantly — explains why WDZ is not a substitute for an EU CPR Euroclass or a North American listing.
Why "WDZ" confuses overseas buyers
Western specs usually name a test standard and a performance class (e.g. "halogen-free to IEC 60754-1, Euroclass Cca-s1b,d1,a1"). Chinese quotes instead name a model code (WDZA-BYJY, WDZC-YJY and similar). The code packs a lot of meaning into four letters, but it says nothing about market access. Buyers who assume "WDZ = LSZH = compliant everywhere" are the ones who get burned at inspection.
Decoding the code: W, D, Z and the A/B/C/D grades
Chinese cable designations under GB/T 19666 (General rules for flame-retardant and fire-resistant wires and cables) are built from letters:
- W = halogen-free — the materials evolve little or no halogen acid gas when burned.
- D = low smoke — smoke emission is limited.
- Z = flame retardant — the cable resists flame propagation.
- ZA / ZB / ZC / ZD = flame-retardant class A / B / C / D, graded by the severity of the vertical bunched-cable burn test. Class A is the most demanding of this family.
- N (when present, e.g. WDZN) = (fire resistant) — circuit integrity maintained under fire, tested to GB/T 19216, the family equivalent of IEC 60331.
So WDZA reads as: halogen-free, low-smoke, flame-retardant class A. WDZC is the same family at the C level. It is a materials-and-flame-performance claim, not a certificate for any particular country.
What GB/T 19666 actually tests
The good news is that China's test methods are largely adoptions of the IEC series, so a genuine Chinese test report looks familiar to a Western engineer:
| Property | Chinese standard | International near-equivalent | What it measures |
|---|---|---|---|
| Flame spread (bunched cable) | GB/T 18380.3x | IEC 60332-3-xx | Char length after a vertical tray burn; drives the A/B/C/D class |
| Smoke density | GB/T 17651.2 | IEC 61034-2 | Light transmittance through smoke (commonly ≥ 60%) |
| Halogen acid gas content | GB/T 17650.1 | IEC 60754-1 | Halogen content (commonly ≤ 0.5%, expressed as HCl) |
| Corrosivity of evolved gases | GB/T 17650.2 | IEC 60754-2 | pH (commonly ≥ 4.3) and conductivity (commonly ≤ 10 µS/mm) |
Values above are the widely used thresholds; always confirm the exact limits and edition against the supplier's current test report, since standards are revised.
The international equivalents buyers actually recognise
- IEC 60754-1 / -2 — halogen-free by gas analysis and corrosivity.
- IEC 61034-2 — smoke density / light transmittance.
- IEC 60332-3-10 — bunched-cable flame spread, with its own A/B/C/D categories.
- EN 50575 (EU Construction Products Regulation) — reaction-to-fire Euroclasses B2ca, Cca, Dca, Eca, Fca, determined by EN 50399 (or EN 60332-1-2 for the lower classes), with add-on suffixes for smoke (s1/s2/s3), flaming droplets (d0/d1/d2) and acidity (a1/a2/a3).
⚠️ The critical gap: WDZ is not a CPR Euroclass
This is the single most expensive misunderstanding in Chinese cable sourcing.
GB/T 19666 and EN 50575 use different test rigs and different classification logic. A bunched-burn result under GB/T 18380 does not convert into an EN 50399 heat-release result, so no supplier can honestly claim "WDZA = Cca". A cable can be legitimately WDZA and still have no declared Euroclass at all.
Practical consequences:
- EU market: the cable must be tested to EN 50575, carry a Declaration of Performance (DoP) naming the Euroclass plus s/d/a suffixes, and be CE marked. A GB/T report is not sufficient.
- North America: the authority having jurisdiction (AHJ) works from the NEC and UL listings; a GB/T code carries no weight at inspection.
- Other regulated markets (UK/BS, Brazil/ABNT, Korea/KS, etc.) each require their own approval.
Treat "WDZ" as a materials family claim, and treat market access as a separate certification you must buy and document.
Family-level mapping (not a 1:1 substitute)
| Chinese grade | Rough international family | Market access |
|---|---|---|
| WDZA | IEC 60332-3 category A bunched burn + halogen-free + low smoke | Still needs EN 50575 / UL / local approval |
| WDZB | Same family, class B | Same |
| WDZC | Same family, class C | Same |
| WDZD | Same family, class D (more limited) | Same |
| WDZN | Adds fire resistance (GB/T 19216 ≈ IEC 60331 family) | Same |
🔴 All correspondences above are family-level, not model-by-model substitutions. Never write or accept "WDZ directly replaces X" without the target-market test report.
Buyer checklist: what to demand in the RFQ
- Ask for the test report, not the code. Request GB/T 19666 class plus the IEC-equivalent reports: IEC 60754-1/-2, IEC 61034-2, IEC 60332-3.
- If the destination is the EU: demand an EN 50575 DoP with the explicit Euroclass and s/d/a suffix, and confirm CE marking.
- If North America: demand the applicable UL listing and NEC-compliant construction.
- State halogen limits numerically (halogen content, pH, conductivity) instead of writing only "LSZH".
- Check the whole construction. "WDZ" should cover insulation and sheath — not just one layer.
- Watch DZ vs WDZ. A "DZ" (low smoke, flame retardant) claim without the "W" is not halogen-free.
For the EU side of this, see our EN 50575 CPR Euroclass guide, and for the material question behind the halogen-free claim, XLPO vs XLPE vs LSZH.
FAQ
Q1: Is WDZ the same as LSZH? A: Close in intent, not identical in definition. WDZ means halogen-free + low smoke + flame retardant under GB/T 19666; LSZH in Western specs is normally defined by passing IEC 60754 (halogen), IEC 61034 (smoke) and a flame test. Ask for the IEC reports to confirm equivalence.
Q2: Does WDZA equal CPR class Cca? A: No. They come from different test regimes (GB/T 18380 bunched burn vs EN 50399 heat release). A WDZA cable can have no Euroclass at all. For the EU you must obtain an EN 50575 DoP stating the actual class.
Q3: What does the A/B/C/D in WDZA, WDZB, WDZC, WDZD mean? A: The flame-retardant class under GB/T 19666, graded by the severity of the vertical bunched-cable burn test. A is the most demanding of the family, D the least.
Q4: Can I install a WDZ cable in the EU if I have the GB/T test report? A: Not on that basis alone. The CPR requires EN 50575 classification, a Declaration of Performance and CE marking for cables placed on the EU market. The GB/T report supports the material claim but is not market access.
Q5: How do I verify a supplier's halogen-free claim? A: Ask for IEC 60754-1 (halogen acid gas content) and IEC 60754-2 (pH and conductivity) test reports from an accredited lab, with the report number and date — then check that the tested construction matches what you are buying.
Sourcing note
🔴 Disclaimer: the mappings in this article are standard-family correspondences for buying guidance, not certified equivalences. Always obtain current test reports and the target-market certificate before specification or acceptance.
Need halogen-free, low-smoke or fire-resistant cable with the right documentation for your market? Send me the code on your quote and I will tell you what it actually covers — reach me on WhatsApp: nquiry . Pricing follows the day's copper price; confirm by inquiry.
