Many overseas buyers mix up XLPO, XLPE and LSZH. The core point: XLPO and XLPE are cross-linked base materials (mostly for insulation), while LSZH is a flame retardant & environmental property specification. They are not at the same classification level.
By cable.wang Editorial Team · 6 min read · Updated 2026-10-22
1. Basic Definition
XLPE – Cross-Linked Polyethylene
XLPE is polyethylene modified by cross-linking process.
- Pros: Excellent electrical insulation, high voltage resistance, good ageing resistance, cost-effective. Standard XLPE is rated 90℃; radiation cross-linked XLPE can reach 125℃.
- Cons: Standard grade is halogen-containing, not inherently flame retardant. It will drip molten material and generate thick black smoke during combustion. Normal XLPE is NOT LSZH.
- Typical use: Insulation for YJV power cables, insulation layer for many solar cables.
XLPO – Cross-Linked Polyolefin
Polyolefin is a big family including PE, ethylene copolymers and more.
Important note: Chemically speaking, XLPE is one type of XLPO. But in cable trading, when people mention XLPO separately, they usually refer to modified low smoke zero halogen cross-linked polyolefin, to distinguish it from ordinary XLPE.
- Pros: Most commercial XLPO is LSZH formulation. Good flame retardancy, no dripping when burning, high temperature resistance (120℃~125℃ commonly), better flexibility than XLPE.
- Cons: Higher material cost and more difficult extrusion processing.
- Typical use: Insulation & sheath for solar cables, energy storage cables, flexible halogen-free wires.
LSZH – Low Smoke Zero Halogen
⚠️ LSZH is NOT a single raw material grade. It describes a performance requirement.
Cables marked LSZH produce little smoke and release no toxic halogen acid gas in fire.
LSZH base material can be cross-linked XLPO, or non-crosslinked polyolefin.
- Pros: Low smoke density and low toxicity in fire, safe for evacuation. Mandatory for tunnel, railway, marine and high-rise building projects.
- Cons: Comparatively harder, lower tear resistance, higher price.
- Typical use: Fire-resistant cables, railway cables, building wiring, tunnel cables.
2. Comparison Table
| Item | XLPE (Standard Cross-Linked Polyethylene) | XLPO (Trading Term: Halogen-Free Cross-Linked Polyolefin) | LSZH (Low Smoke Zero Halogen) |
|---|---|---|---|
| Nature | Cross-linked polyethylene, sub-category of polyolefin | Modified cross-linked polyolefin blend | Performance specification / formulation standard |
| Halogen | Normally halogen containing | Most are zero halogen | Must be zero halogen |
| Flame retardant | Not inherently flame retardant, needs extra additives | Built-in halogen-free flame retardant system | Flame class adjustable upon request |
| Combustion behaviour | Melting dripping, heavy black smoke, corrosive gas | Low smoke, no dripping, zero halogen gas | Low smoke, low toxicity, best smoke performance |
| Continuous temp rating | 90℃ standard / 125℃ radiation cross-linked | 120~150℃ | 70~125℃, depends on base resin (can be XLPO) |
| Electrical performance | ★★★★★ Best insulation | ★★★★ | ★★★ |
| Cost | Low | Medium-high | Medium-high |
| Common application | Power cable insulation | Solar & energy storage cable insulation + sheath | Building, transit, fire circuit sheath |
3. Common Misunderstandings (For Communication With Buyers)
- ❌ Myth: XLPO = LSZH
✅ Clarification: XLPO is base material; LSZH is an environmental & fire property. XLPO can be LSZH or non-LSZH. Most solar-grade XLPO on market is LSZH type. - ❌ Myth: XLPE = XLPO
✅ Clarification: In chemistry, XLPE belongs to XLPO family. But in commercial quotation, XLPO refers separately to halogen-free flame retardant cross-linked polyolefin, cannot be treated the same as regular XLPE. - ❌ Myth: LSZH is a plastic material name
✅ Clarification: It is a performance requirement, not a resin grade.
4. Quick Selection Guide
- General power cable, superior insulation, tight budget: XLPE insulation
- PV DC cable, energy storage cable, require high temperature resistance, no dripping, halogen free: XLPO (LSZH formulation)
- Metro, tunnel, high-rise fire wiring where low smoke non-toxic is compulsory: LSZH cable
FAQ
Q: Is XLPO the same as LSZH?
No. XLPO is a cross-linked base material (a modified, halogen-free polyolefin blend), while LSZH is a performance specification describing low smoke and zero halogen emission in fire. XLPO can be formulated as LSZH or not, but most commercial solar-grade XLPO on the market is LSZH type. Treat them as different classification levels: material vs. property.
Q: Can standard XLPE be used for solar PV DC cables?
Standard XLPE works as an insulation base and is used in many power cables, but PV DC cables normally call for XLPO in an LSZH formulation. The reason is compliance and safety: solar cables sit in high-temperature, outdoor and often enclosed environments where no-dripping, halogen-free and higher temperature rating (commonly 120–125°C) matter. Standard XLPE is halogen-containing, drips when burning and emits thick black smoke, so it is not the default for PV applications.
Q: Is LSZH a raw material or a standard?
LSZH is a performance requirement, not a resin grade. A cable marked LSZH must produce little smoke and release no toxic halogen acid gas during combustion. Its base material can be cross-linked XLPO, or a non-crosslinked polyolefin — the LSZH label tells you the fire/smoke behaviour, not the chemistry of the polymer itself.
Q: What temperature ratings do XLPE, XLPO and LSZH reach?
Standard XLPE is rated 90°C, with radiation cross-linked grades reaching 125°C. Commercial XLPO commonly runs 120–125°C and some grades reach 150°C. LSZH temperature rating depends on its base resin and typically spans 70–125°C. Always confirm the exact continuous and short-circuit ratings on the cable specification rather than assuming by material name.
Q: Which is more cost-effective, XLPE or XLPO, and when is LSZH worth the premium?
XLPE is the lowest cost with the best electrical insulation, so it is the economical choice for general power cable where fire-smoke rules are not strict. XLPO costs more (higher material and extrusion difficulty) but is the right call for PV, energy storage and flexible halogen-free wires. LSZH carries a premium and is worth it wherever low-smoke, non-toxic evacuation is mandated — tunnels, railways, marine and high-rise buildings. Match the spec to the application, not to the price tag.
Conclusion: XLPO and XLPE differ in base material and flame-retardant formulation; LSZH is a performance standard, not a material name. For PV cables, XLPO (LSZH-grade) is the default choice for safety and compliance. Match the spec to the application — not to the price tag.
