Detailed Description
What Is LSZH Cable?
LSZH (Low Smoke Zero Halogen) cable is a power or control cable in which the outer sheath — and optionally the core insulation — is made from a mineral-filled polymer compound that, when exposed to fire, emits no halogen acid gases (HCl, HBr, HF) and produces minimal smoke. The LSZH designation is defined by three IEC standards: IEC 60754-1 (zero halogen — HCl <0.5%), IEC 60754-2 (low acidity — pH >4.3, conductivity <10 μS/mm), and IEC 61034-2 (low smoke — ≥60% light transmittance).
LSZH cable is specified for buildings and enclosed spaces where the fire safety strategy requires cables that do not contribute to the two primary hazards of burning cables: toxic and corrosive gas (from PVC's chlorine content) and dense, vision-obscuring smoke. In a building fire, the majority of fatalities are caused by smoke inhalation, not burns. PVC cables contribute significantly to both smoke density and toxic gas production. LSZH cables eliminate the halogen gas hazard and reduce the smoke hazard to a level that maintains visibility for evacuation and firefighting.
LSZH vs PVC — The Fire Safety Comparison
| Fire Safety Parameter | PVC Cable | LSZH Cable | Test Standard |
|---|---|---|---|
| Halogen acid gas (HCl) | 20–30% HCl by weight of PVC | <0.5% (halogen-free) | IEC 60754-1 |
| Smoke density (light transmittance) | <20% (dense black smoke — visibility <2 m) | >60% (visibility 8–10 m) | IEC 61034-2 |
| Combustion gas acidity (pH) | <2.0 (highly acidic — HCl dissolves to hydrochloric acid) | >4.3 (mildly acidic from CO₂ dissolution only) | IEC 60754-2 |
| Corrosion damage to electronics | Severe — HCl + moisture = hydrochloric acid corrosion of copper, solder, steel | Minimal — no halogen acids to cause corrosion | — |
| Flame retardance mechanism | Chlorine radicals in gas phase | Endothermic decomposition of ATH/MDH + water vapor release + char formation | — |
| Flame retardance effectiveness | Good — PVC is inherently flame-retardant | Good — mineral flame retardant loading of 50–60% by weight provides equivalent or better flame retardance | IEC 60332-1/3 |
| CPR Euroclass (typical) | Dca or Eca | Cca or B2ca | EN 50575 / EN 13501-6 |
The practical consequence for building design: a building wired with PVC cable that experiences an electrical fire in a cable riser shaft will have the riser shaft filled with dense, black, acidic smoke. The smoke will migrate to upper floors through the riser, reducing visibility in escape stairs to near zero, and the HCl gas will cause respiratory distress and eye irritation in occupants. The same building wired with LSZH cable will have significantly less smoke (visibility maintained for minutes longer, which can be the difference between successful evacuation and fatalities) and no HCl gas to attack occupants' respiratory systems or the building's steel reinforcement and electronic systems after the fire.
Why Choose Yichi LSZH Cables
- IEC 60754 / IEC 61034 type-tested and certified: The halogen-free and low-smoke performance is verified by testing at an ISO/IEC 17025 accredited laboratory. The test report demonstrates the cable's HCl emission (<0.5%), smoke density (>60% transmittance), and combustion gas acidity — not claims from the material data sheet
- CPR Euroclass B2ca to Dca — your choice per the building fire strategy: B2ca-s1a,d1,a1 for escape routes and high-risk areas; Cca for general building areas; the CPR Declaration of Performance (DoP) is provided with every cable batch and is the legal evidence of compliance for the EU market
- XLPE + LSZH or full LSZH construction: Standard construction uses XLPE core insulation (halogen-free PE) + LSZH sheath — a cost-effective combination that provides the electrical performance of XLPE with the fire safety of LSZH. Full LSZH construction (LSZH insulation + LSZH sheath) is available for applications where every cable layer must be LSZH — typically hospitals, data centers, and tunnels
- Mineral flame retardant system — ATH/MDH, not halogenated additives: The LSZH compound's flame retardance comes from aluminum trihydrate and magnesium dihydrate — minerals that absorb heat and release water vapor when heated. This is why LSZH is halogen-free: it does not rely on halogen chemistry for flame retardance. The mineral loading (50–60% by weight) provides the fire performance; the polymer binder provides the mechanical properties
- Full 0.6/1 kV power and 300/500 V control range — halogen-free throughout: One manufacturer for the complete building LSZH cable specification — power distribution cables, control cables, and (with fire-resistant options) life safety cables — all with the same qualified LSZH compound on the outer sheath