Halogen-free and LSZH cables are now indispensable components in the quest for improved fire safety, the safeguarding of sensitive equipment and compliance with stringent regulations within the industrial environment of today. These cables mitigate toxic smoke and corrosive gases during a fire event, thus protecting personnel, electronics and infrastructure in state-of-the-art plants. They are increasingly being called for by engineers and plant managers in the automation industry, in control cabinets and critical infrastructure where PVC cables cannot be used.
Whether you are installing, replacing, or purchasing new products, this guide offers practical guidance and information on halogen-free and LSZH materials, the various standards involved, relevant industry use cases, and design best practices to help you make well-informed decisions for safe, compliant installations.
What “Halogen-Free” and LSZH Mean in Modern Cable Design
Halogen Free cables are designed to be free from the presence of chlorine, fluorine, bromine and iodine in their compounds used for the insulation and jacket. This means that undesirable halogen acid gases are not released during combustion, thereby reducing the toxicity and corrosion potential in the event of a fire.
Halogen-Free Cables
“Halogen-free” means “material-based” halogen-free. It prevents the emission of corrosive products of combustion harming the machinery or electronics. But performance depends on the label as well as conforming to certain fire-behaviour criteria.
LSZH / LSOH / LS0H Cables
LSZH (Low Smoke Zero Halogen) cables feature low smoke and zero-halogen materials. Emit low amounts of visible smoke and no acidic gases, enhancing the ability to see during evacuations and to keep sensitive equipment safe. The chemistry is defined as “halogen-free”, while the focus on LSZH is on tested fire performance.
Materials Used in Halogen-Free and LSZH Industrial Cables
Choosing the proper compounds is essential for durability under industrial use environments such as flexing, temperature fluctuation and chemical exposure.
Common Halogen-Free Jacket and Insulation Materials
Hulk Electric has specialties in advanced halogen-free solutions that employ high performance materials like cross-linked polyolefins (XLPO), thermoplastic elastomers (TPE), polyurethane (PUR), silicone rubber and polyethylene blends. These offer excellent flexibility, mechanical strength and environmental resistance specifically designed for drag chains, robotics and automation applications.
Flame-Retardant Mechanisms in LSZH Compounds
Incorporation of mineral fillers in LSZH formulations, such as aluminum trihydrate (ATH) and magnesium hydroxide. These are endothermic in nature and, on being heated, release water vapour to bring the flame back down to extinguish the smoke without producing corrosive gases. It is important to maintain flexibility and abrasion resistance when using high filler loads, especially when compounding.
Key Standards and Tests for Halogen-Free / LSZH Cables
Ensuring conforming cables operate as expected in a real fire is done by complying with international standards.
Halogen Acid Gas Content – IEC 60754
This standard is used for measuring acidity, pH, conductivity of combustion gas, which results in minimal emission of halogen and reduced corrosiveness.
Smoke Density – IEC 61034
Smoke opacity is measured in terms of the 3m cubed test. The light transmission of LSZH cables is high (usually ≥60-70%), better than PVC, and can maintain good visibility.
Flame Propagation – IEC 60332 Series
These tests assess the single-cable and bundled flame spread characteristics, which provide self-extinguishing properties that restrict fire spread from one cable to another.
Regional and Application-Specific Standards
Check for EN 50575 (CPR) standards in Europe, UL standards in North America and others such as BS 7211. Our RoHS, REACH and industry-specific (Industrial automation) certified halogen-free cables are produced at Hulk.
Where Halogen-Free and LSZH Cables Are Used in Modern Industrial Plants
These cables are ideal for applications where fire safety, uptime and equipment protection are critical.
Power and Control Circuits in Safety-Critical Areas
In electrical rooms, MCCs, control panels and evacuation routes, LSZH cables are the best option to protect people and minimize corrosion damage to valuable equipment after fire.
Industrial Automation, Machinery and Conveyors
Halogen-free and LSZH cables are used to reliably carry signals and power for the industrial robotics market, material handling applications, and food processing lines, where motion and washdown are often frequent. Hulk’s high flex halogen-free models have been designed for such demanding applications.
Data, Communication and Network Infrastructure in Plants
Control system, vision system and plant IT infrastructure are shielded against smoke and corrosive damage from sensitive networks by LSZH Ethernet, fieldbus and sensor cables.
Design and Installation Best Practices for LSZH Cables in Industrial Environments
Handling properly for maximum performance and life.
Handling, Bend Radius and Pulling Tension
Follow manufacturer’s bending and tension recommendations. Some lszh jackets may be stiff because of fillers, use proper tools and don’t bend in sharp angles that may cause cracking.
Routing and Environmental Protection
Use smooth trays or conduits to route cables away from abrasion areas. Keep out UV, chemicals and mechanical stresses, particularly in outdoor or high flex areas.
Matching Cable Type to Function and Standards
It is important to consider the type of cable to be used in combination with the function and standards.
Always check datasheets for precise specifications of voltage, temperature, flex cycles and fire performance ratings.
Designing for Maintenance and Future Expansion
The design must be tailored to meet the needs for maintenance and future expansion.
Schedule for flexibility and convenience. Maintain uniformity when upgrading plants by documenting specifications.
The performance and total cost of ownership of the cable are balanced with safety using the right halogen-free and LSZH cables. Modern industrial plants are more reliable and regulatory compliant by paying attention to materials, standards, and application-specific design.
Offering customized high-flex halogen free, LSZH cable for industrial automation, robotics and more at Guangdong Hulk Electric (Dongguan) Co., Ltd. Our team has the in-house production capability, rigorous testing and global certifications to support engineers in specifying solutions that operate reliably in real operating conditions. Tell us about your project requirements, and we’ll help you get your next plant upgrade.
