April 25, 2019

LSZH cables: an update on fire performance standards

Some demanding environments require high safety requirements in case of fire. Various standards guarantee the fire behaviour of cables, such as the CPR.

The installation of LSZH cables is suitable in these environments, emitting little smoke when subjected to fire. CAE GROUPE offers various fire resistant cables to meet your safety needs.

Why install LSZH cable?


LSZH cables are cables that emit low-density, halogen-free smoke when exposed to fire.

These LSZH (Low Smoke, Zero Halogen) cables are therefore particularly suitable for sites where the risk of fire can have serious consequences both in human terms and for the protection of property.

This includes public buildings, industries such as steel, chemicals, marine and nuclear sectors.


In the event of a fire, the combustion of PVC sheathed cables causes the release of opaque fumes and corrosive gases that are dangerous to humans, installations and industrial equipment.

It is therefore important to take into account the composition of these cables when dealing with fire safety. LSZH materials are preferred to reduce this risk.

Standards governing the fire performance of cables


Cables, like all building materials, must meet fire safety requirements. There are various standards to ensure this, which can be international according to IEC, European EN and national NF.

The latest regulation is EN 50575, more commonly known as CPR (Construction Product Regulation). It allows for European harmonisation of reaction-to-fire tests for cables and fixed wiring elements installed in a building.

The results of the tests lead to a classification of the performance and quality of the products. The 7 fire performance classes are called EUROCLASSES.

To find out more about the CPR regulations, read our article Adopt the right level of fire performance for your cabling infrastructure

The RPC does not replace all fire performance standards; they complement each other.

The other standards recognised and applied by cable companies are :


- NF C32-070 test C2 equivalent to IEC 60332-1: the cable is recognised as “flame retardant”

- NF C32-070 C1 test: the cable is recognised as “non-fire propagating”


The notion of "non-fire propagation" corresponds to the IEC 60332-3 standard. As the test protocols are different, we cannot speak of strict equivalence with NF C 32-070 C1.


IEC 60754-1 and 60754-2 (EN 50267-2-1 and 50267-2-2) define the ZH criteria by measuring the amount of halogenated acid gases emitted during combustion and the acidity level of these gases.

IEC 61034-1 and 2 define LS (Low Smoke) by measuring the density of smoke emitted from burning cables.


These French or international standards for the fire behaviour of cables coexist with the CPR for products related to the construction of a building. French legislation is still in transition between these two standards, the content of the decrees varies according to the environment (industry/building).