A Quick Overview of FRLS Cables


FRLS is a pseudonym for Flame Retardant Low Smoke Cables. Designed to prevent the spread of fire and to lower the level of smoke and toxic gas during combustion.

Understanding how FRLS Works

Flame retardant is a substance that initiates chemical reactions to form a protective layer on the surface which refrains the cable from spreading the fire.

Low Smoke is a usually Polyolefin based material capable of forming a mineral hydration to give off cleaner smoke when burned.

Used in highly populated areas like:

  • Home and Apartments
  • Offices, Commercial & Retail Buildings
  • Schools and Libraries
  • Malls, Hotels, and Hospitals
  • Mass Transit – Airports, Railway Carriages, and Subways

Difference between FR & FRLS Cables

Fire Retardant (FR) cables are designed to restrict the fire from spreading into new areas. On combustion, like ordinary PVC Cables, it produces large amounts of black toxic smoke that block sighting and severely disrupt the evacuation and firefighting activities. Generated toxic fumes can cause severe irritation, and if inhaled, are considered lethal to humans.

Like we already discussed, FLRS cables are equipped with low smoke compounds to reduce the level of toxic fumes, negligible smoke, and desirably less corrosive gases. In the case of fire hazard, people can be evacuated safely to the exit.

There you have the difference.

Construction of most typical FRLS Cables

Image Courtesy: Havells
  • Conductor – Made of high conductivity copper, usually stranded
  • Insulation – Formulated with flame retardant materials (typically PVC)
  • Armour – Galvanised steel armouring to prevent rusting
  • Heat Barrier – High sustaining tape to absorb excessive heat
  • Inner and Outer sheath – made of low smoke compounds
  • Colours – Outer layer is colour-coded for easy identification in housewires and instrumentation cables
  • Voltage – Up to 1.1 kV

The cable construction varies slightly by brand, depending on demand and supply chains. Check the labels for full specifications.

General properties of FRLS Cables

    • ASTM-D 2863 – Standard test for measuring the minimum oxygen and temperature index
    • IEC 60332-1 & IEC 60332-3 – Flame tests on electric and optical fiber cables
    • IEC 60754-1 – Determination of the halogen acid gas evolved during combustion of electric cables
    • ASTMD -2843 – Standard test method for density of smoke during combustions
    • IEC 61034 – Measurement of the smoke density emitted from cables

Top Manufacturers of FRLS Cables in India

Polycab: Ranked India’s No.1 cable and wire manufacturing company in 2012. Polycab is a household brand name, best known for its cabling products in India.

Finolex: As per the survey was done by Business Today, Finolex is one of the best wealth creating companies in India. The company boasts of using 99.97% pure electrolytic quality copper conductors with virgin grade PVC in their built-up.

Havells: Deals with all kinds of electrical products ranging from household appliances to industrial cables. Havells enjoys dominance in the industrial as well as domestic market.

RR Kabels: Thrives on manufacturing Industrial cables to adhere to international standards. RR Kabels has received several commendations, which speaks for their quality.

KEI: Started with measly switchboard cables. Since then, within five years – KEI steadily expanded its product range to cover all types of cable and wires.

Where to go from here: You can read the difference between FRLS and FRLZ cables. I have seen people often get confused with these two types of cables due to lack of technical feasibility.


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