What is True “Halogen-Free”?
According to the IEC 60754-1 standard, a cable is considered truly halogen-free if it emits less than 0.5% hydrogen halide gas when burned. This means materials must contain no fluorine, chlorine, bromine, or iodine. True halogen-free cables reduce toxic gas emissions and corrosion in case of fire, protecting human health and electronic equipment.
Comparison of Mainstream Halogen-Free Materials: LSZH vs. TPU vs. EVA
Halogen-free cable insulation and sheathing use various materials, each with distinct properties. LSZH (Low Smoke Zero Halogen) compounds are widely used for their low emissions and flame retardancy. TPU (thermoplastic polyurethane) offers superior mechanical strength and abrasion resistance but at a higher cost. EVA (ethylene-vinyl acetate) provides excellent flexibility and processing ease but may sacrifice flame resistance. The selection depends on application-specific requirements such as flexibility, strength, cost, and fire safety.
| Material | Halogen-Free | Flame Retardant | Flexibility | Mechanical Strength | Cost |
|---|---|---|---|---|---|
| LSZH | Yes | Excellent | Medium | Good | Medium |
| TPU | Yes | Good | High | Excellent | High |
| EVA | Yes | Fair | Excellent | Moderate | Low |
“Smoke Density” Testing of Halogen-Free Cables
Smoke generation is a critical safety indicator, especially for enclosed environments like tunnels or subways. Halogen-free cables produce far less smoke compared to traditional PVC cables. Under smoke density testing (as per IEC 61034), typical PVC cables show smoke density values exceeding 600, severely reducing visibility. In contrast, LSZH cables demonstrate values below 100, making them critical for emergency escape scenarios. Data shows that at a distance of 3 meters, PVC smoke reduces visibility to 0%, while LSZH maintains over 60%. This performance not only supports evacuation but also protects sensitive electronics from acidic smoke corrosion.
Debate on the Lifespan of Halogen-Free Cables
While halogen-free materials are environmentally friendly, they are often thought to have shorter service lives due to reduced UV and heat resistance compared to PVC. However, modern LSZH formulations have significantly improved in durability, achieving similar lifespan performance in indoor or shielded applications. Aging remains a concern only under harsh UV or thermal cycling conditions without additional protection.
Cost Analysis: Why Are Halogen-Free Cables 30%–50% More Expensive?
Halogen-free cables are more expensive mainly due to raw material costs—LSZH and TPU compounds are pricier than PVC. Additionally, the manufacturing process requires specialized extrusion equipment and tighter quality control to ensure low-smoke, non-corrosive behavior during fires. Smaller production scales and strict compliance with fire and toxicity standards further increase the cost burden.
Conclusion and Customer Recommendations
For enclosed or public spaces, halogen-free cables offer critical fire safety advantages. We recommend using LSZH cables for all sensitive or human-occupied environments, despite the slightly higher cost, for maximum protection and regulatory compliance.
