What Is LSZH Wire and Cable?
LSZH means low smoke zero halogen. It describes cable materials selected to limit smoke and halogen-acid gas under specified fire-test conditions. The abbreviation does not identify one universal cable design, performance class, or approval. Buyers should name the required product specification and test methods instead of treating “LSZH” as a complete datasheet.
An LSZH cable may use low-halogen or halogen-free insulation and jacket compounds, but the full construction matters. Conductors, fillers, tapes, binders, printing inks, and other components can affect whole-cable behavior. A label on the jacket alone does not prove that every component or the finished cable meets a project requirement.
“Wire” often means one insulated conductor, while “cable” usually refers to one or more conductors assembled into a construction. Industry terminology varies. For procurement, list the conductor count, size, insulation, jacket, shielding, ratings, length, and required evidence so suppliers quote the same item.
Why Specify LSZH Cable?
Project teams may specify LSZH where limiting smoke obscuration or halogen-acid gas during a fire is part of the building, transport, equipment, or customer requirement. This can be relevant in occupied or enclosed spaces where evacuation, visibility, corrosion concerns, or system recovery matter. LSZH materials do not prevent a fire, guarantee safe evacuation, or establish that a cable is suitable for every installation.
Typical project discussions include public buildings, rail and transit systems, data centers, industrial facilities, ships, tunnels, and equipment installed in confined areas. These are examples of contexts where a project may call for low-smoke or halogen-free properties, not a universal rule that every cable in those environments must be LSZH. Applicable building, transport, marine, product, and installation rules vary by jurisdiction and system.
The useful question is not simply “Is this cable LSZH?” Ask what defined fire behavior is required, which cable construction is covered, how the requirement will be verified, and which authority or customer specification governs acceptance. A system designer or compliance specialist should confirm those requirements before ordering.
What Is Inside an LSZH Cable?
LSZH is generally achieved through material selection and compound formulation. Jacket and insulation suppliers may use different polymer blends and additives to balance smoke, halogen content, flame behavior, processing, flexibility, and durability. “Halogen-free” does not identify a single polymer, and a material-family name alone does not prove the performance of the finished cable.
The cable architecture still needs to match its electrical and mechanical duty. A basic design can include copper conductors, conductor insulation, cores or pairs, fillers, wrapping, an optional metallic shield, and an outer sheath. Power, control, data, and flexible cables require different conductor geometries and electrical properties. Adding an LSZH outer sheath does not automatically make an otherwise unsuitable cable appropriate for a circuit.
| Cable element | What to define | Why it matters |
|---|---|---|
| Conductor | Copper or other specified metal, size, strand construction, core count | Sets electrical resistance, current and voltage-drop design inputs, and termination compatibility |
| Insulation | Material designation, thickness or construction, voltage and temperature ratings | Controls electrical separation and affects thermal and mechanical behavior |
| Core arrangement | Numbering, color, pairs, lay, and filler details | Affects identification, signal performance, assembly, and fit |
| Shield | Foil, braid, drain wire, coverage and termination method | Supports the specified electromagnetic compatibility design |
| Jacket/sheath | Exact compound or performance specification, color, diameter and markings | Affects environmental protection, handling, and fire-performance evidence |
| Finished assembly | Connectors, terminals, branches, labels, strain relief, sealing | Determines interface, fit, and finished-product acceptance |
When a cable includes an LSZH jacket but uses other materials inside, project requirements may still be met—or may not be. The answer depends on the governing product specification and the test scope. Request a datasheet and test documentation tied to the exact construction and revision being quoted.
Which LSZH Fire Tests Should Buyers Check?
Low smoke, halogen-acid gas, and flame propagation are separate characteristics. A test for one does not establish the others. The IEC catalogue describes IEC 60754-1 as a method for determining halogen-acid gas from materials taken from cable construction, IEC 61034-2 as a procedure for measuring smoke density from burning cables under defined conditions, and IEC 60332-1-2 as a single insulated wire or cable vertical flame-propagation test. Specify the applicable edition and acceptance criteria for your project; the standard number alone may not contain every requirement.
| Requirement | Example test family | What the buyer should confirm |
|---|---|---|
| Halogen-acid gas | IEC 60754 series | Part and edition, measured property, material or whole-cable scope, threshold, and report sample identity |
| Smoke density | IEC 61034 series | Part and edition, test configuration, acceptance criterion, and whether the required product construction was tested |
| Flame propagation | IEC 60332 series | Applicable part, single-cable or bunched-cable arrangement, specimen configuration, and pass criteria |
| Product approval or system rule | Applicable cable, building, transport, or customer specification | Jurisdiction, installation method, certification scope, marking, and documentation required for acceptance |
Do not infer a universal pass threshold from the acronym LSZH. Different sectors and product specifications can set different test configurations, minimum values, or combinations of tests. If a project cites a classification or harmonized product standard, have the responsible compliance engineer confirm the exact edition and applicable product category.
A useful supplier evidence package identifies the manufacturer, cable type, part number, construction, tested sample, laboratory or issuing body, test standard and edition, date, result, and scope. Check whether the report covers the finished cable or only a compound specimen. A compound test can support material verification but does not by itself certify the complete cable or its installation.
LSZH vs. PVC and Other Cable Choices
No jacket material suits every project. A lower-smoke or halogen-free requirement may be important, while cost, processing, abrasion, moisture, chemicals, cold flexibility, temperature, and service life remain part of the decision. Compare specified cable products and test evidence rather than relying on broad material labels.
| Selection factor | LSZH construction | PVC construction | Practical decision |
|---|---|---|---|
| Fire-related smoke and gas | Formulated to meet specified low-smoke and halogen-related criteria when tested | Performance depends on the exact compound; do not assume it meets an LSZH requirement | Name the test methods and limits required by the project |
| Mechanical and environmental behavior | Varies by compound and cable design | Also varies by compound and cable design | Check abrasion, oils, chemicals, water, UV, temperature, and flex data for the exact part |
| Electrical function | Determined by conductor, insulation, geometry, and cable ratings | Same principle | Confirm voltage, temperature, current design, impedance or signal needs, and shielding |
| Cost and availability | May affect material options, lead time, and cost depending on specification | Broadly used in many cable constructions, subject to its rating | Compare equivalent constructions and total project requirements |
| Installation approval | Must meet the applicable product and installation rules | Must meet the applicable product and installation rules | Obtain approval for the selected cable in its intended system |
An LSZH designation is not a direct substitute for flame retardance, fire resistance, circuit integrity, plenum suitability, outdoor rating, or toxicity performance. Those terms describe different properties or regulatory classifications. If the cable must continue operating during a fire, verify the required circuit-integrity system and support method separately; a low-smoke jacket alone does not establish continued operation.
Performance Trade-Offs and Design Checks
Material selection affects more than fire-test results. Some LSZH compounds may be stiffer or behave differently during stripping, routing, or connector assembly than a familiar PVC construction. Actual performance varies by formulation and product, so confirm measurements from the exact cable rather than treating any general comparison as a guaranteed rule.
Before approval, check these design inputs:
- Electrical rating: conductor size, voltage, current design, resistance, voltage drop, dielectric performance, and signal or impedance needs.
- Temperature: conductor operating temperature, ambient range, storage conditions, and temperature rise in the actual installation.
- Movement: fixed routing, occasional movement, repeated flexing, torsion, drag-chain use, bend radius, and expected cycle life.
- Environment: moisture, oils, cleaning agents, chemicals, abrasion, vibration, sunlight, and installation inside or outside an enclosure.
- Termination: conductor strand class, insulation diameter, strip length, contact compatibility, crimp tooling, sealing, and strain relief.
- Fire evidence: specified test methods, current editions, specimen construction, acceptance limits, and project approvals.
- Manufacturing control: part-number and revision control, lot identification, incoming inspection, and change notification.
For a harness or cable assembly, materials and terminations must work together. A tight bend near a connector, an incompatible contact barrel, damaged insulation during stripping, or poor strain relief can undermine reliability even when the cable itself meets its datasheet. Route and terminate the cable according to the actual drawing and supplier process limits.
How to Specify LSZH Wire and Cable
A complete request for quotation (RFQ) translates “LSZH” into a verifiable product definition. State the application and governing specification, then provide the construction, electrical requirements, installation environment, and required evidence. If a parameter is not known, identify it for engineering review instead of allowing suppliers to fill in different assumptions.
| RFQ field | Information to provide |
|---|---|
| Application and destination | Equipment, system, installation location, market, and governing authority or customer specification |
| Cable identity | Manufacturer and part number if known, conductor count and size, insulation, jacket, shield, core arrangement, and color/marking |
| Electrical needs | Voltage, current design inputs, temperature rating, data or signal requirements, impedance, and shielding/grounding details |
| Mechanical and environmental needs | Length, bend radius, fixed or moving use, abrasion, moisture, oils, chemicals, UV, vibration, and temperature range |
| Fire requirements | Test standard and edition, required parts, acceptance thresholds, specimen scope, report or certification needs |
| Assembly details | Connector and terminal part numbers, pinout, branch lengths, labels, protective sleeves, sealing, and strain relief |
| Commercial and quality details | Prototype quantity, annual volume, packaging, inspections, tests, traceability, revisions, and change-control expectations |
Ask the supplier to confirm any proposed substitutions in writing. Review whether the alternative matches the electrical ratings, construction, fire evidence, approval scope, dimensions, and termination compatibility. A supplier statement that a replacement is “equivalent LSZH” is not enough when the project relies on a specific product approval or test report.
How OUKETECH Can Support an LSZH Cable Project
OUKETECH supplies custom cable assemblies and wire harnesses built to customer drawings and specifications. For an LSZH project, the appropriate scope is to review the specified cable and material documentation, coordinate the required construction for the assembly, and manufacture the defined interconnect where the project requirements and available evidence can be confirmed. Cable availability, certification scope, fire-test documentation, and suitability must be checked for each requested part number。
For a finished assembly, the drawing should identify cable part number and revision, connector interfaces, pinout, finished length, branch dimensions, labels, sleeves, strain relief, shielding termination, inspection criteria, and required electrical tests. OUKETECH’s custom cable assembly manufacturing and custom wire harness manufacturing guide explain the build-to-print assembly context. Buyers comparing supplier scope can review the OEM cable manufacturing overview.
Before a quotation, share the governing LSZH specification and the cable manufacturer’s technical documents. OUKETECH can then clarify whether the specified cable and assembly details can be supported, what evidence is available, and which open questions need customer or engineering approval. For project review, use the OUKETECH contact page and include the drawing, BOM, quantities, required approvals, and test expectations.
FAQ
What does LSZH mean on a cable?
LSZH means low smoke zero halogen. It signals material and fire-performance expectations, but does not define one universal cable construction or approval. Confirm the exact test methods and acceptance criteria.
Is LSZH cable fireproof?
No. LSZH does not mean fireproof. It does not by itself prove flame resistance, fire survival, circuit integrity, or continued operation. Specify each required fire property and the applicable system approval separately.
Does LSZH mean zero smoke?
No. “Low smoke” means smoke behavior is measured against defined test conditions and criteria. It does not mean no smoke is produced. The project specification should identify the test method and limit.
Are LSZH and halogen-free cable the same?
The terms are related but not interchangeable in every specification. LSZH emphasizes smoke and halogen-acid gas behavior under defined tests. “Halogen-free” can refer to a material-content requirement. Use the customer’s exact definitions and test methods.
Is LSZH always better than PVC?
No. The right choice depends on fire requirements, mechanical and environmental conditions, electrical design, cost, availability, and approval needs. Compare exact cable constructions and supporting documentation.
What documents should I request from an LSZH cable supplier?
Request the exact part-number datasheet, construction details, relevant test reports or certificates, test standards and editions, sample identity, report scope, ratings, markings, and change-control information. Confirm whether evidence covers the compound, finished cable, or assembly.
Can OUKETECH make an LSZH cable assembly?
OUKETECH supports custom cable assemblies and wire harnesses to customer specifications. Whether a particular LSZH cable, approval, test report, connector, and assembly configuration can be supplied must be confirmed during project review. Provide the specification and drawing for assessment.
Request an LSZH Cable Assembly Review
Send OUKETECH your cable specification, required fire-test standards, datasheets or approved part numbers, drawing, BOM, connector list, pinout, target quantities, and inspection requirements. The team can review the assembly scope and identify any open material, documentation, or approval questions before quotation.