The question each word answers
A flame-retardant cable is designed so that it does not carry a fire along its length. Once the source of the flame is removed, or once the flame reaches the end of a test ladder, the fire on the cable stops within a set distance. The relevant tests are IEC 60332-1-2 for a single cable and IEC 60332-3 for bunched cables, and in the EU the reaction-to-fire classes of the CPR. The cable itself may be destroyed; what matters is that it does not become a fuse that spreads fire between floors or rooms.
A fire-resistant cable is designed so that the circuit keeps working while the cable is in a fire, for a defined time. This property is called circuit integrity. The relevant tests are IEC 60331, BS 6387 (with its C, W and Z categories) and the EN 50200 route used in BS 8519. Fire-resistant cables are used for circuits that must keep running during an emergency: fire alarms, emergency lighting, smoke extraction, sprinkler pumps, firefighting lifts and evacuation systems.
Put simply: flame-retardant protects the building from the cable; fire-resistant protects the circuit from the fire. Most fire-resistant cables are also flame-retardant, but most flame-retardant cables are not fire-resistant.
The words also translate poorly. Supplier catalogues in several languages use terms that can mean either property, and a direct translation of a product name may read as "fire-resistant" when the cable has only passed a flame spread test. That is one more reason to specify by test standard rather than by description: a standard number means the same thing in every language and at every plant.
Side by side
| Point | Flame-retardant | Fire-resistant |
|---|---|---|
| Question answered | Does the cable spread fire? | Does the circuit keep working in a fire? |
| Typical tests | IEC 60332-1-2, IEC 60332-3 categories A to D, CPR classes under EN 50575 | IEC 60331, BS 6387 CWZ, EN 50200 and BS 8519 categories |
| Typical construction | Flame-retardant PVC or LSZH sheath and fillers | Mica tape fire barrier over the conductor, then insulation and usually an LSZH sheath; or mineral insulation |
| Typical uses | General power and lighting, cable trays, risers | Fire alarm, emergency lighting, smoke control, firefighting and life safety circuits |
| How it is stated on our pages | Flame-retardant to IEC 60332-1-2 or 60332-3 per test report | Circuit integrity to IEC 60331, BS 6387 CWZ or BS 8519 per test report |
What makes a cable fire-resistant
The usual construction adds a fire barrier directly over the conductor. Our reference construction on the fire-resistant cables page is 0.6/1 kV Cu/Mica/XLPE/LSZH 4x25 mm2: annealed copper conductor, mica tape, XLPE insulation, fillers and binder tape, and a low smoke zero halogen flame-retardant sheath, with outer diameter and weight per datasheet. In a fire the organic insulation and sheath burn away, while the mica layer stays in place around the conductor and keeps the cores apart for long enough to pass the test.
A second route is mineral insulation, where the conductors are surrounded by an inorganic insulating material inside a metal sheath. A partner plant catalogue lists a 0.6/1 kV mica tape mineral insulated corrugated aluminium sheathed 4x25 mm2 construction at about 39 mm overall diameter and about 1,749 kg/km, made to an enterprise standard. The mineral insulated cables guide covers these types.
The mica tape, the number of layers and the way the tape is applied all affect the result. That is why a circuit integrity claim belongs to a specific construction and a specific test report, not to a cable type in general.
Where buyers get it wrong
The first mistake is asking for a "fire cable" without saying which property is needed. Suppliers will often quote the cheaper flame-retardant construction, because it fits the words. On a project where the circuit feeds a smoke extraction fan, that cable would fail the specification at inspection, after it has been installed.
The second mistake is the opposite: specifying fire-resistant cable for general circuits that only need flame-retardant cable. Mica tape and the extra testing add material and time, so the cable costs more per metre and the choice of partner plants is narrower. The project engineer decides which circuits need circuit integrity; the rest can usually be flame-retardant.
The third mistake is reading a CPR class as fire resistance. A high CPR class such as B2ca says the cable contributes little to a fire; it does not say the circuit will keep working. Fire-resistant cables in EU buildings often need both a CPR class declared on the DoP and a circuit integrity test report, as two separate documents. The CPR classes guide explains the code.
The fourth mistake is accepting a label instead of a report. BASEC has publicly warned about cables sold as fire-resistant that turned out to have aluminium conductors and poor fire performance. A sheath print saying "fire resistant" proves nothing; the report, the tested construction and the plant's quality records do.
How to specify each one
- Flame-retardant only: "flame-retardant to IEC 60332-1-2" or "to IEC 60332-3-24 category C per test report", plus the CPR class if relevant.
- Fire-resistant: the circuit integrity standard and duration, for example "circuit integrity to IEC 60331 per test report" or "BS 6387 CWZ per test report", or the BS 8519 category for UK life safety systems.
- Smoke and acid gas: IEC 61034 and IEC 60754-1 or -2 if an LSZH sheath is required; see the smoke and acid gas test guide.
- Construction: conductor size and class, mica tape, insulation, sheath and core count, so the plant can match the construction to its reports.
- Quantity and timing: total metres per size and drum lengths, so the desk can check MOQ and lead time with the plant.
Fire-resistant constructions are a narrower field than standard power cable. The desk shortlists partner plants that already hold circuit integrity reports for the construction, often in special cable clusters such as Wuwei in Anhui and Yixing in Jiangsu, and checks each report before a sample or trial drum is agreed. Typical MOQ and lead time wording is on the MOQ and lead time page, and every order is confirmed in writing. Send the circuit list through the quote form and mark which circuits need circuit integrity.