| Full title | Fire classification of construction products and building elements. Part 6: Classification using data from reaction to fire tests on power, control and communication cables |
| Publisher | CEN (European Committee for Standardization); published in the UK by BSI as BS EN 13501-6 |
| Current edition | EN 13501-6:2018+A1:2022. BS EN 13501-6:2018+A1:2022 published 30 November 2023 |
| Status | Current. Supersedes EN 13501-6:2018 |
| Class source | Commission Delegated Regulation (EU) 2016/364, Table 4 |
| Related standards | EN 50399, EN 60332-1-2, EN ISO 1716, EN 61034-2, EN 60754-2, EN 50575 |
What it covers
EN 13501-6 gives the procedure for classifying the reaction to fire performance of electric cables. In this standard, “electric cables” means all power, control and communication cables, including optical fibre cables.
The classes and their limits are set in law by Commission Delegated Regulation (EU) 2016/364, Table 4. EN 13501-6 explains how test data from the named test methods are used to assign a class. It does not describe the tests themselves. Those are in the test standards listed below.
Reaction to fire is about how a cable contributes to a fire: how far flame spreads, how much heat and smoke it gives off, whether it drops burning material and how acidic its fire gases are. It is not the same as fire resistance, which is about a cable keeping a circuit working during a fire.
The main classes
There are seven main classes. Aca is the best. Fca is the class for a cable that does not meet Eca, meaning its flame spread H in EN 60332-1-2 is more than 425 mm.
| Class | Test methods | Classification criteria |
|---|---|---|
| Aca | EN ISO 1716 | Gross calorific potential PCS ≤ 2.0 MJ/kg |
| B1ca | EN 50399 (30 kW flame source) and EN 60332-1-2 | FS ≤ 1.75 m, THR1200s ≤ 10 MJ, peak HRR ≤ 20 kW, FIGRA ≤ 120 W/s, H ≤ 425 mm |
| B2ca | EN 50399 (20.5 kW flame source) and EN 60332-1-2 | FS ≤ 1.5 m, THR1200s ≤ 15 MJ, peak HRR ≤ 30 kW, FIGRA ≤ 150 W/s, H ≤ 425 mm |
| Cca | EN 50399 (20.5 kW flame source) and EN 60332-1-2 | FS ≤ 2.0 m, THR1200s ≤ 30 MJ, peak HRR ≤ 60 kW, FIGRA ≤ 300 W/s, H ≤ 425 mm |
| Dca | EN 50399 (20.5 kW flame source) and EN 60332-1-2 | THR1200s ≤ 70 MJ, peak HRR ≤ 400 kW, FIGRA ≤ 1300 W/s, H ≤ 425 mm |
| Eca | EN 60332-1-2 | H ≤ 425 mm |
| Fca | EN 60332-1-2 | H > 425 mm |
For Aca, the PCS limit applies to the product as a whole, excluding metallic materials, and to any external component such as the sheath.
Abbreviations
- FS: flame spread (damaged length) in the EN 50399 test.
- THR1200s: total heat release over the 1200 s test.
- Peak HRR: highest heat release rate during the test.
- FIGRA: fire growth rate index.
- H: flame spread in the EN 60332-1-2 single cable test.
- PCS: gross calorific potential, measured in a bomb calorimeter to EN ISO 1716.
Additional classifications
Classes B1ca, B2ca, Cca and Dca must also carry a smoke class, a flaming droplets class and an acidity class. Aca, Eca and Fca have no additional classification.
Smoke production (s)
| Class | Criteria |
|---|---|
| s1 | TSP1200 ≤ 50 m² and peak SPR ≤ 0.25 m²/s |
| s1a | s1 and light transmittance ≥ 80% to EN 61034-2 |
| s1b | s1 and light transmittance ≥ 60% but < 80% to EN 61034-2 |
| s2 | TSP1200 ≤ 400 m² and peak SPR ≤ 1.5 m²/s |
| s3 | Not s1 or s2 |
TSP1200 is total smoke production over 1200 s and SPR is smoke production rate, both measured in the EN 50399 test. For B1ca the declared smoke class must come from the 30 kW test. For B2ca, Cca and Dca it must come from the 20.5 kW test.
Flaming droplets and particles (d)
| Class | Criteria |
|---|---|
| d0 | No flaming droplets or particles within 1200 s |
| d1 | No flaming droplets or particles persisting longer than 10 s within 1200 s |
| d2 | Not d0 or d1 |
Acidity (a)
| Class | Criteria (EN 60754-2) |
|---|---|
| a1 | Conductivity < 2.5 μS/mm and pH > 4.3 |
| a2 | Conductivity < 10 μS/mm and pH > 4.3 |
| a3 | Not a1 or a2 |
Reading a classification
A full classification is written as the main class followed by the additional classes, for example Cca-s1b,d1,a1. Read it as:
- Cca: met the Cca limits in EN 50399 at 20.5 kW and passed EN 60332-1-2.
- s1b: low smoke in EN 50399, with 60% to under 80% light transmittance in EN 61034-2.
- d1: no flaming droplets lasting more than 10 s.
- a1: the lowest acidity band in EN 60754-2.
A lower letter or number is always the better performance. Each part of the code is set by a separate measurement, so a cable can be strong on one and weaker on another.
How it relates to other standards
| Standard | Role |
|---|---|
| EN 50399 | Large-scale vertical ladder test. Gives FS, HRR, THR, FIGRA, SPR, TSP and flaming droplets for B1ca to Dca |
| EN 60332-1-2 | Single cable 1 kW flame test. Gives H for B1ca to Fca |
| EN ISO 1716 | Heat of combustion (PCS) for Aca |
| EN 61034-2 | Smoke density test. Splits s1 into s1a and s1b |
| EN 60754-2 | Acidity and conductivity of fire gases. Gives a1 to a3 |
| EN 50575 | Harmonised product standard for cables under the CPR. Calls up EN 13501-6 for the declared class |
The EN 60332-3 bunched cable tests are not used for CPR classification. They are a separate family of tests.
What it means in practice
- The reaction to fire class appears on the cable’s Declaration of Performance and its CE marking label, with the full code including s, d and a.
- A classification is only as good as the test evidence behind it. The classification report should name the test standards and the flame source used.
- When a specification calls for a minimum class, check every part of the code. A Cca-s3,d2,a3 cable and a Cca-s1a,d0,a1 cable share the same main class but are very different in smoke, droplets and acidity.
- Reaction to fire classes say nothing about circuit integrity in a fire. Fire resistant cables are tested to other standards.
Related reading: What is LSZH cable and when do you need it?.