When choosing the right cables in enclosed industrial environments, it goes beyond mere power transmission. When fire hazards occur, cables can provide critical protection for personnel and equipment, especially the LSZH cables, which are low in smoke and emit no halogens. These cables are designed to produce little smoke and no corrosive halogen acids when burned, which directly helps to ensure that people can be evacuated safely and less secondary damage will be done in a limited vent area.
We’ve supported engineers and plant managers in automation, robotics, and heavy industry specifying both performance and safety demanding, halogen-free solutions at Hulk Electric. This guide outlines practical issues regarding ventilation, smoke behavior, toxic gas risks and evacuation, which will help you decide about your facility.
Why Enclosed Industrial Spaces Need Special Attention
Some areas are enclosed, as opposed to covered production floors, that have their own fire safety issues. Smoke and gases are likely to build up quickly in underground rooms, cable tunnels, equipment corridors or sealed control areas where the air is not free to circulate.
Unlike the normal PVC cables which can release corrosive gases and thick black smoke, halogen-free cables employ less dense smoke and fewer corrosive acids. The difference can make a big difference as far as visibility, air quality, and being able to safely evacuate.
How Halogen-Free Cables Change Fire Behaviour
Smoke Density and Visibility
LSZH cables are specially designed to provide a higher level of light transmittance before and after fire, typically retaining 60% or more of the visibility. By contrast, standard cables will absorb 50% of the light after just minutes and up to 90% after only a few hours in an enclosed space, making it difficult to find exit routes or emergency signage.
In large complex industrial layouts, the increased visibility is essential, and rapid orientation can save lives.
Toxic and Corrosive Gas Emissions
PVC burning creates immediate health hazards with the release of hydrogen chloride and other halogen acids that will destroy sensitive electronics, drives, PLCs, and instrumentation. The Halogen-free cables significantly reduce acid emissions (typically ≤0.5% HCl according to the relevant standards) which reduces the inhalation hazards and costly damage to equipment after the incident.
Typical Enclosed Industrial Spaces Where LSZH Is Recommended
Underground and Tunnel-Like Areas
Lack of natural ventilation in cable basements, utility tunnels, and between buildings. In these areas, halogen free cables are the preferred cable to not fill up the cabinets quickly and facilitate safer emergency responses.
Enclosed Plant Rooms and High-Density Equipment Areas
Industrial spaces like control rooms, MCC rooms, PLC enclosures, and server spaces are where critical systems reside along with cabling. The options offered by LSZH provide protection against corrosive byproducts, for both operators and costly automation equipment.
Public-Access or High-Occupancy Industrial Areas
Specific areas like training centres, loading bays (if there is one) or visitor entry areas in industrial complexes may have higher requirements for public safety. Halogen free cabling fits in with these higher standards.
Ventilation, Smoke Risk and Evacuation – How to Decide
When assessing cable specifications adopt this practical workflow:
Step 1 – Map Ventilation Quality
Evaluate each space: open space with good ventilation vs poorly ventilated and/or mechanically restricted areas such as closed corridors and underground rooms. Areas where the airflow is limited should receive greater consideration for LSZH cables.
Step 2 – Assess Occupancy and Evacuation Complexity
Consider the number of staff, length and complexity of escape routes and the risk of smoke-filled areas. Cables that are halogen free will significantly enhance the chances of evacuation, as they will preserve visibility and air quality.
Step 3 – Evaluate Equipment Sensitivity and Recovery Needs
Take into account the value and density of the surrounding electronics. Limiting corrosive gas exposure helps minimise downtime and replacement following any incident.
When Halogen-Free Is Clearly Worth the Premium
Use halogen free / LSZH cables when space is:
- In enclosed areas or places with little air exchange (tunnels, under cover, closed rooms, etc.)
- High occupancy or complicated evacuation routes
- Analyze critical control systems and electronics so they can be housed.
For good reason, many standards and local regulations place focus on or impose requirements for LSZH in high-risk enclosed environments.
Where Conventional Cables Can Still Be Used
Where risk assessments and local codes permit, standard grade cables can be used in ventilated open plant areas, where the density of cables is moderate and escape routes are short in length, and where the total does not exceed the low level of occupancy. But do not use them in areas where smoke and toxicity can still be a problem, such as small or equipment-filled areas.
Practical Specification Tips for Enclosed Industrial Spaces
- Specify LSZH requirements in project specs (e.g., “All cables in enclosed control rooms and tunnels shall be halogen-free LSZH”).
- Use key standards like IEC 60332 (flame retardancy), BS EN 60754 (halogen acid gases) and IEC 61034 (smoke density).
- Partner with seasoned manufacturers that offer complete traceability, test reports, and user-specific configurations.
Our cables are halogen free with the same high standards as our high flex, servo, robot and high temp silicone lines at Hulk Electric (Dongguan) Co., Ltd. We have more than 35 international certifications and decades of real-world application experience to ensure reliable performance to satisfy strict safety requirements.
Provide your project information including space types, ventilation profiles or particular standards and our team will be able to advise you on best practice solutions for your enclosed industrial applications, without using halogen.
