Get in touch with us
On this page:

    Revit Guides

    Data Management

    ELI5

    Since July 2017, all power, control and communication cables permanently installed in buildings must comply with the Construction Products Regulation (CPR). This includes classification under BS EN 13501-6, which assesses cables for their reaction to fire. This guide is your reference for navigating Euroclass ratings, selecting compliant products, and understanding where each cable type fits into UK practice.

    BS EN 13501-6 vs BS EN 13501-1

    Although both use similar notation (B, C, D, etc.), they involve different test methods. For example, B2ca for cables is not the same as B for wall linings, but both imply strong fire performance.

    Euroclass Ratings for Cables (BS EN 13501-6)

    ClassPlain-English meaning (short)Typical notes
    AcaNo contribution to fire (effectively non-combustible)Rare for cables
    B1caVery limited contribution to fireStricter than B2ca
    B2caLimited contribution to fireCommon high-spec class; tested incl. EN 50399
    CcaControlled contribution to fireTested incl. EN 50399
    DcaAcceptable basic performanceLower than Cca; limited flame spread
    EcaBasic flame propagation pass onlyEntry level
    FcaNo performance determined / fail EcaAvoid for escape routes

    Higher up the list = better fire performance (Aca → B1ca → B2ca → Cca → …).

    Optional modifiers you can append to the class

    You’ll often see a full designation like B2ca-s1a,d1,a1.

    SuffixWhat it controlsOptions (best → worst)Plain-English meaning
    sSmoke productions1a, s1b, s2, s3s1a = very low smoke; s1b = low smoke; s2 = moderate; s3 = no limit
    dFlaming droplets/particlesd0, d1, d2d0 = none; d1 = none persisting >10 s; d2 = no requirement
    aAcidity/corrosivity of gasesa1, a2, a3a1 = very low; a2 = limited; a3 = no requirement

    Minimum Euroclass Recommendations (UK context)

    Fire Classification for Cables

    • BS 7671 requires cable flame-prop limits and ≥60% light transmittance to BS EN 61034-2 when cables are permitted in protected escape routes. The “≥60%” aligns with CPR “s1b” (s1a ≥80%, s1b ≥60%–<80%). 

    • Classes Cca / B2ca use the EN 50399 large-scale flame spread & heat release test (on top of EN 60332-1-2), giving a robust flame-prop baseline that dovetails with the Wiring Regs’ “non-flame-propagating” intent. 

    • d1 (limited flaming droplets) and a2/a1 (limited acidity) are not explicitly set in BS 7671, but they’re widely adopted in UK practice for escape routes because they support tenability (reduced burning droplets/corrosive smoke). These attributes are part of the EN 13501-6 scheme.

    Cable classification example:

    Minimum: Cca-s1b,d1,a2:

    • Cca: limited fire growth/heat release and controlled flame spread under EN 50399.
    • s1b: low smoke– light transmittance ≥60% and <80% (the s1 family is the most stringent for smoke; s1a ≥80%). 
    • d1: Limited flaming droplets/particles – none persisting >10 s. (d0 = none at all; d2 = no requirement)
    • a2: Limited (intermediate) acidity of combustion gases (less stringent than a1, more than a3); assessed to EN 60754-2 within the EN 13501-6 scheme.

    Preferred: B2ca-s1a,d1,a1

    • B2ca: Stricter cable class than Cca (very limited contribution to fire growth/heat release) per EN 50399.
    • s1a: Very low smoke– light transmittance ≥80%
    • d1: Limited flaming droplets/particles – none persisting >10 s.
    • a1: Very low acidity/corrosivity of combustion gases.

    Common Cable Types and Ratings (with UK product examples)

    Prysmian FP600S (BS 7846-F120) meets the latest CPR Euroclass rating:

    • B2ca–s1a, d1, a1, which is superior to B-s3, d2.
    • B2ca: Higher fire resistance than B-s3.
    • s1a: Very low smoke production (better than s3).
    • d1: Minimal flaming droplets (better than d2).

    General Guidance

    • CPR Class should be printed on the sheath
      E.g. “BASEC Approved, CPR: Cca-s1a,d1,a1”
    • LS0H cables feel softer than PVC — more prone to nicking on sharp edges
    • If in doubt — use Cca or better in public areas or risers
    • Fca = fail → Do not install

    Other Multicore SWA Options

    If, for some reason, FP600S is not suitable (cost, availability, or otherwise), you can look at alternative BS 7846-F120 or fire-rated SWA cables from other manufacturers – many now offer B2ca–s1,d1 (or s1a,d1) ratings. Examples include:

    • Draka Firetuf Powerplus (sometimes listed as B2ca–s1,d1,a1)
    • Nexans Fire-Performance Armoured cables meeting BS 7846-F120 & CPR B2ca

    Always confirm with the manufacturer’s datasheet or DoP (Declaration of Performance) that the specific drum/batch of cable has the required CPR rating.

    This post is related to the Wiring in Protected Escape Route guidance where you find much more usefull info. 

    Main image downloaded from: https://cpr.europacable.eu/  Accessed: 2025-06-04

    On This page

      Leave a Reply

      Your email address will not be published. Required fields are marked *

      share this page