In building and construction, cable selection is an important aspect of overall fire safety. The Construction Products Regulation (CPR provides a harmonised European framework for assessing and classifying the reaction-to-fire performance of cables based on measurable criteria.
This performance-based approach enables cables to be assessed using harmonised test methods rather than assumptions based solely on the type of material they contain.
Why Choose PVC Cables?
PVC cables combine fire performance with the electrical, mechanical and economic characteristics required for a wide range of building and infrastructure applications.
Best Cost/Performance Ratio
Fire Safety
Circular Economy
Fire Safety and CPR Compliance
For cables permanently installed in construction works, the CPR establishes a common framework for declaring reaction-to-fire performance.
The classification of the complete cable takes account of several fire performance parameters, including:
- heat release and fire growth
- flame spread
- smoke production
- flaming droplets or particles
- acidity of combustion gases
No single parameter determines the overall fire performance of a cable. The resulting classification reflects how the complete cable performs under standardised fire tests.
PVC cable systems can be designed to achieve different CPR classifications depending on their construction, formulation and intended application.
Cable Classification Under EN 13501-6
Electric cables are classified according to their reaction-to-fire performance in classes ranging from Aca to Fca.
For cables with a combustible polymer content, the principal classes include:
- B1ca and B2ca – very limited contribution to fire
- Cca – limited contribution to fire
- Dca – higher permitted levels of heat release and fire growth than Cca
- Eca – meets defined requirements for vertical flame spread
- Fca – does not meet the requirements for Eca or has no performance determined under the relevant criteria
PVC cables can achieve demanding classifications including B2ca, depending on the cable design and formulation.
For classes B1ca, B2ca, Cca and Dca, additional classifications provide further information on:
- s – smoke production
- d – flaming droplets and particles
- a – acidity, based on pH and conductivity
For example, d0 indicates that no flaming droplets or particles occur during the specified test period. Smoke class s1 represents the most demanding main smoke-production category and can be further differentiated as s1a and s1b.
The CPR classification therefore provides a more complete description of cable fire performance than the polymer type alone.
The specific reaction-to-fire class required for a particular building or application is determined by national requirements in the EU Member States.
Performance in Case of Fire
PVC contains chlorine as an integral part of its polymer structure. This contributes to its resistance to ignition and flame propagation.
Modern PVC cable compounds can be formulated to provide a combination of:
- good resistance to ignition
- limited flame spread
- controlled heat release
- low smoke production
- absence of flaming droplets
The precise performance depends on the formulation and construction of the finished cable. This is why fire performance should be assessed using the classification of the complete cable rather than assumptions about an individual material.
Continuous developments in formulation technology have enabled PVC cables to achieve increasingly demanding levels of reaction-to-fire performance while maintaining the electrical, mechanical and durability characteristics required for cable applications.
A Performance-Based Approach
The CPR is based on demonstrated cable performance.
Terms such as “halogen-free” describe the chemical composition of a cable material but are not in themselves fire safety classifications. Cables made from different materials can therefore be assessed using the same harmonised test and classification framework.
For designers and specifiers, the relevant consideration is whether the finished cable achieves the reaction-to-fire performance required for its intended application.
Relevant Standards
The principal European standards relevant to the reaction-to-fire testing and classification of cables include:
- EN 13501-6 – Fire classification of construction products and building elements – Classification using data from reaction-to-fire tests on power, control and communication cables
- EN 50575 – Power, control and communication cables for general applications in construction works subject to reaction-to-fire requirements
- EN 50399 – Measurement of heat release and smoke production during flame spread testing of cables
- EN 60332-1-2 – Vertical flame propagation test for a single insulated wire or cable
- EN 61034-2 – Measurement of smoke density of cables burning under defined conditions
- EN 60754-1 – Determination of halogen acid gas content of gases evolved during combustion of cable materials
- EN 60754-2 – Determination of acidity by pH measurement and conductivity of gases evolved during combustion
- EN 50576:2022 – Extended application of test results for reaction to fire of electric cables