H07Z1-K and H07Z-K are both flexible, single-core, halogen-free building wires rated 450/750 V, but they are not the same cable designation.
H07Z1-K is commonly specified to EN 50525-3-31 with a Class 5 flexible copper conductor and halogen-free thermoplastic insulation, typically with a maximum conductor operating temperature of 70°C.
H07Z-K is commonly specified to EN 50525-3-41 with a Class 5 flexible copper conductor and halogen-free cross-linked insulation designed for a 90°C conductor operating temperature.
Neither designation should automatically be described as fire-resistant. LSZH performance, flame propagation performance, and circuit integrity during fire are different technical properties and must be verified against the applicable test standards and project documents.
For buyers, contractors, distributors, and project engineers, the correct selection therefore requires more than checking whether the quotation says “LSZH cable.” The cable designation, standard, insulation compound, temperature rating, fire tests, CPR classification where applicable, and supporting documents must all agree.
Quick Answer: What Is the Difference Between H07Z1-K and H07Z-K?
The main technical difference is the insulation system and its associated temperature class.
| Item | H07Z1-K | H07Z-K |
|---|---|---|
| Typical product standard | EN 50525-3-31 | EN 50525-3-41 |
| Rated voltage | 450/750 V | 450/750 V |
| Conductor | Class 5 flexible copper | Class 5 flexible copper |
| Insulation family | Halogen-free thermoplastic compound | Halogen-free cross-linked compound |
| Typical maximum conductor temperature | 70°C | 90°C |
| Low-smoke / halogen-free focus | Yes, subject to specified tests | Yes, subject to specified tests |
| Flame propagation | Verify exact test and product documentation | Verify exact test and product documentation |
| Fire-resistant circuit integrity | Not established by designation alone | Not established by designation alone |
| Typical selection reason | LSZH flexible fixed wiring | LSZH flexible wiring where 90°C construction is specified |
Do not substitute one for the other only because both are described commercially as “LSZH building wire.”
The project specification should identify the exact designation and applicable standard.
What Is H07Z1-K Cable?
H07Z1-K is a harmonized, flexible, single-core, halogen-free wire intended for fixed and protected electrical installations.
A typical construction includes:
- Plain annealed copper conductor
- Class 5 flexible conductor construction
- Halogen-free thermoplastic insulation
- Rated voltage of 450/750 V
- Typical maximum conductor operating temperature of 70°C
The flexible conductor makes H07Z1-K practical for conduit, trunking, distribution boards, switchgear, control equipment, and other locations where routing a rigid conductor would be less convenient.
However, the letter sequence should not be treated as a marketing shortcut.
When a quotation says H07Z1-K, buyers should confirm that the supplier’s datasheet actually identifies EN 50525-3-31 and that the insulation, dimensions, conductor construction, voltage rating, marking, and fire-performance documentation correspond to that product.
What Is H07Z-K Cable?
H07Z-K is another harmonized, flexible, single-core halogen-free cable, but it belongs to a different insulation and temperature family.
H07Z-K specified to EN 50525-3-41 uses a Class 5 flexible copper conductor with halogen-free cross-linked insulation and is associated with a maximum conductor operating temperature of 90°C.
Typical applications may include:
- Switchboards
- Distribution boards
- Electrical cabinets
- Control panels
- Protected fixed wiring
- Industrial equipment
- Public-building electrical systems
The 90°C insulation rating does not, by itself, mean that H07Z-K can carry more current in every installation.
Final conductor sizing can still be limited by the installation method, ambient temperature, grouping, terminal ratings, protective device, local wiring rules, and project design.
H07Z1-K vs H07Z-K: Why the Insulation Difference Matters
The difference between thermoplastic and cross-linked insulation is more important than it may appear from the cable name.
H07Z1-K under EN 50525-3-31 is generally associated with a halogen-free thermoplastic insulation system and a 70°C conductor operating temperature.
H07Z-K under EN 50525-3-41 uses a halogen-free cross-linked insulation system designed for a higher conductor operating temperature.
This does not make one universally “better” than the other.
The correct product is the one required by the project specification.
For example, a building specification calling specifically for H07Z1-K should not automatically be changed to H07Z-K simply because the second product has a higher insulation temperature. Approval, dimensions, termination, CPR declaration, local rules, and the original project design may also matter.
LSZH, Flame-Retardant and Fire-Resistant Are Not the Same Thing
This is the most important technical distinction when specifying H07Z1-K or H07Z-K cable.
The three terms describe different aspects of cable behavior during a fire.
| Term | What It Describes | What It Does Not Automatically Prove |
|---|---|---|
| LSZH / LSOH | Low smoke and reduced halogen-related combustion products | Circuit integrity during fire |
| Flame-retardant | Ability to limit flame propagation under a specified test | Low smoke, zero halogen or continued electrical operation |
| Fire-resistant | Ability to maintain circuit integrity for a specified period under defined fire conditions | Automatically low smoke or halogen-free unless separately tested |
LSZH
LSZH means Low Smoke Zero Halogen or Low Smoke Halogen Free, depending on market terminology.
For procurement purposes, the phrase itself is not enough.
The buyer should identify which tests support the claim. Depending on the specification, documentation may refer to areas such as:
- Halogen acid gas content
- Acidity and conductivity of combustion gases
- Smoke density or light transmission
IEC 60754-series and IEC 61034-series tests are commonly referenced for these performance areas.
A supplier writing only “LSZH” on a quotation without identifying the actual standard or supporting report leaves an important technical gap.
Flame-Retardant
Flame-retardant performance is concerned with limiting the spread of flame.
IEC 60332 is a commonly used family of cable flame-propagation tests. However, even within IEC 60332 there are different test arrangements and categories.
For example, a test on a single vertical insulated conductor is not the same as a test on vertically mounted bunched cables.
Therefore, a buyer should not request simply:
Flame retardant cable
A better requirement identifies the applicable test standard and, where relevant, the required category.
Fire-Resistant
Fire resistance is different again.
A fire-resistant cable is expected to maintain electrical circuit integrity for a specified test period under defined fire conditions.
Circuit-integrity tests belong to a different test family, such as applicable IEC 60331 requirements.
Passing an IEC 60332 flame-propagation test does not establish IEC 60331 circuit integrity.
Likewise:
LSZH ≠ fire-resistant
and:
Flame-retardant ≠ fire-resistant
If emergency lighting, fire alarms, smoke extraction systems, evacuation equipment, or other safety circuits must continue operating during a fire, the required circuit-integrity standard must be specified separately.
Does H07Z1-K Automatically Mean Flame-Retardant?
Do not rely on the designation alone to describe every fire-performance level required by a project.
Commercial H07Z1-K products commonly provide flame-propagation, low-smoke, and halogen-free performance, but the buyer should still verify:
- Exact EN cable standard
- Product type or variant
- Flame test reference
- Smoke test reference
- Halogen/corrosivity test reference
- CPR class where applicable
- Declaration of Performance
- Third-party approval where specified
Some manufacturers offer different reaction-to-fire classes or product variants under the broader H07Z1-K family.
Therefore, do not automatically copy a CPR class such as Cca, Dca, or Eca from another manufacturer’s datasheet into your own RFQ.
The class must match the product actually being supplied.
Does H07Z-K Automatically Mean Fire-Resistant?
No.
H07Z-K is a halogen-free, low-smoke flexible single-core cable designation, but that does not automatically make it a circuit-integrity cable.
Its 90°C insulation system describes thermal capability under the relevant product standard.
It does not prove continued electrical operation during fire.
If the project requires a fire-resistant cable, request the specific circuit-integrity standard and test report separately.
This distinction prevents one of the most common procurement errors: approving an LSZH cable for a circuit that actually requires fire survival.
H07Z1-K / H07Z-K vs H07V-K
H07V-K is one of the most useful reference products because all three cable types can use flexible Class 5 copper conductors and may look similar from the outside.
The critical difference is insulation.
H07V-K is a PVC-insulated flexible building wire, while H07Z1-K and H07Z-K use halogen-free insulation systems.
| Comparison | H07V-K | H07Z1-K | H07Z-K |
|---|---|---|---|
| Typical standard | EN 50525-2-31 | EN 50525-3-31 | EN 50525-3-41 |
| Rated voltage | 450/750 V | 450/750 V | 450/750 V |
| Conductor | Class 5 copper | Class 5 copper | Class 5 copper |
| Insulation | PVC | Halogen-free thermoplastic | Halogen-free cross-linked |
| Typical max conductor temperature | 70°C | 70°C | 90°C |
| LSZH | No | Yes, subject to specified tests | Yes, subject to specified tests |
| Low-smoke focus | No | Yes | Yes |
| Halogen-free | No | Yes | Yes |
| Flame propagation | Verify product test | Verify product test | Verify product test |
| Fire-resistant by designation | No | No | No |
| Typical selection | General protected wiring | LSZH protected wiring | 90°C LSZH protected wiring |
H07V-K should therefore not be described simply as the “non-fireproof version” of H07Z-K.
That wording mixes several independent cable properties.
PVC cables can still meet specified flame-propagation requirements while remaining halogen-containing and producing different smoke and combustion-gas characteristics from LSZH cable.
Similarly, an LSZH cable is not automatically fire-resistant.
For a more detailed comparison of PVC flexible and rigid building wire, see our H07V-U vs H07V-K cable guide.
When Should You Choose H07V-K Instead?
H07V-K remains a practical building wire where:
- PVC insulation is permitted by the specification
- LSZH performance is not required
- The installation is protected
- 70°C insulation is suitable
- Local wiring requirements permit the product
- Cost control is important
It is widely used for protected wiring in conduits, panels, electrical equipment, and similar indoor applications.
A project should not automatically be upgraded or downgraded between H07V-K and H07Z cable types without checking its fire strategy and local requirements.
For a broader overview of common European-style building wires, see our building wire types guide.
Where Are H07Z1-K and H07Z-K Used?
These cable families are primarily intended for protected fixed-wiring applications where flexible conductors and reduced fire emissions are required.
Electrical Cabinets and Switchboards
Class 5 conductors are easier to route between breakers, contactors, relays, terminals, meters, and control devices.
The cable should still be terminated using an appropriate terminal system for flexible conductors.
Public Buildings
LSZH wiring is frequently specified in projects where smoke generation and corrosive gases are important parts of the fire strategy, including certain:
- Hospitals
- Schools
- Airports
- Commercial buildings
- Hotels
- Transport facilities
- Public buildings
The project specification and local regulations determine whether H07Z1-K, H07Z-K, another LSZH cable family, or a fire-resistant cable is required.
Data Centers and Equipment Rooms
Reduced corrosive combustion products can be important around electronic equipment, but “data center cable” is not a separate approval created by the H07Z designation.
The installation environment, circuit design, fire strategy, containment system, and local requirements must still be checked.
Industrial Panels
H07Z-K can be useful in applications where a Class 5 flexible conductor, halogen-free construction, and 90°C insulation class are specifically required.
Do not interpret its higher insulation temperature as permission to ignore panel terminal ratings or conductor-sizing rules.
What Documents Should a Buyer Actually Check?
A quotation saying:
H07Z1-K, LSZH, CE
is not enough for a technical approval.
For a real procurement review, compare the documents with the physical cable and purchase specification.
1. Product Datasheet
The datasheet should identify the exact product being supplied.
Check:
- H07Z1-K or H07Z-K designation
- Applicable EN standard
- Rated voltage
- Conductor class
- Conductor material
- Size range
- Insulation material
- Maximum conductor temperature
- Insulation thickness
- Approximate outside diameter
- Bending requirements
- Installation limitations
- Fire-performance references
Do not accept a generic LSZH cable datasheet when the quotation is for a specific harmonized designation.
2. Cable Standard and Edition
Confirm whether the offered product is actually specified against:
H07Z1-K
- EN 50525-3-31
H07Z-K
- EN 50525-3-41
H07V-K
- EN 50525-2-31
Also check conductor construction against the relevant conductor standard, commonly IEC/EN 60228 Class 5 for these flexible designs.
A manufacturer writing “IEC cable” without identifying the actual cable standard is not the same as providing a complete specification.
3. Approval or Certification Record
If the project requires HAR or another third-party approval, request the actual approval record.
Check:
- Certificate holder
- Manufacturing location if stated
- Product designation
- Size range
- Voltage
- Applicable standard
- Certificate number
- Validity/status
- Authorized marking
A certificate belonging to another product family does not prove that the offered H07Z cable is covered.
4. CPR Declaration of Performance
Where CPR requirements apply to the cable’s intended use in a European construction project, request the applicable Declaration of Performance (DoP).
Check that the DoP matches:
- Manufacturer
- Product identification
- Cable family
- Reaction-to-fire class
- Intended use
- Referenced standard
- Assessment body information where applicable
Do not assume that every H07Z1-K or H07Z-K cable automatically has the same CPR class.
A designation such as H07Z1-K describes the cable family; a CPR reaction-to-fire class describes another declared performance characteristic.
5. Flame-Propagation Test Report
If the project specifies flame retardancy, identify the exact test.
The report should match the cable or material scope required by the specification.
Do not accept:
Flame retardant: Yes
as the complete requirement.
Confirm the standard and, where relevant, test category.
6. Halogen and Combustion-Gas Reports
For an LSZH claim, check the reports supporting the halogen-free or low-corrosivity performance.
Depending on the project specification, relevant documentation may include tests addressing:
- Halogen acid gas content
- Acidity
- Conductivity of combustion gases
The test report should identify the tested compound or cable construction clearly enough to connect it to the supplied product.
7. Smoke-Density Test Report
Low-smoke claims should also have a defined test basis.
Smoke-density testing measures smoke generation under specified test conditions rather than providing a general statement that a cable “does not smoke.”
The report and specification should identify the relevant standard and acceptance requirement.
8. Fire-Resistance Report — Only If Required
If the circuit must remain operational during fire, request the separate circuit-integrity test report required by the project.
This is not replaced by:
- LSZH certification
- IEC 60332 flame testing
- CPR reaction-to-fire classification
- A 90°C insulation rating
The fire-resistance test, exposure conditions, duration, cable construction, support method, voltage, and other project requirements must match the specification.
9. Conductor and Dimensional Test Data
For bulk procurement, request or inspect actual production data where required.
Useful checks include:
- Conductor DC resistance
- Conductor construction
- Nominal cross-section
- Insulation thickness
- Outside diameter
- Voltage withstand
- Finished cable appearance
- Color
- Marking
The physical product should match the approved datasheet rather than only the quotation description.
10. Cable Marking and Traceability
Before shipment, request a photograph or sample of the cable legend.
Check that the marking agrees with the approved documents for:
- Manufacturer or brand
- H07Z1-K / H07Z-K designation
- Size
- Voltage
- Standard or approval marking where applicable
- Production identification
- Other required project information
Our electrical cable jacket markings guide explains how to compare printed cable legends with certification and production records.
A perfect-looking cable print is not enough by itself, but inconsistent printing is an immediate reason to investigate further.
A Practical Document Cross-Check
Do not review each document independently.
Cross-check them against each other.
| Item | Datasheet | Certificate / Approval | DoP | Test Report | Cable Marking |
|---|---|---|---|---|---|
| Manufacturer | ✓ | ✓ | ✓ | ✓ | ✓ |
| Cable designation | ✓ | ✓ | ✓ | ✓ | ✓ |
| Standard | ✓ | ✓ | ✓ | ✓ | Where required |
| Voltage | ✓ | ✓ | — | Where relevant | ✓ |
| Size / size range | ✓ | ✓ | Product dependent | ✓ | ✓ |
| Fire performance | ✓ | Scope dependent | ✓ for CPR | ✓ | Product dependent |
| Batch traceability | Product dependent | — | — | Preferable | ✓ |
If one document says H07Z1-K, another certificate covers H07V-K, and the cable itself is marked only “LSZH 450/750 V,” the technical package should not be approved without clarification.
What Should Be Checked on a Sample?
Before approving a bulk order, a sample can be checked for more than appearance.
Compare:
- Cable marking
- Conductor flexibility
- Strand construction
- Conductor size
- Insulation thickness
- Outside diameter
- Surface finish
- Color
- Stripping behavior
- Packaging label
- Datasheet
- Test documentation
For material-related procurement, our wire compound and PVC cable compound guide explains why compound type and declared material properties should not be reduced to simple labels such as PVC or LSZH.
Common Buying Mistakes
Mistake 1: Assuming Every LSZH Cable Is Fire-Resistant
It is not.
LSZH concerns smoke and halogen-related fire emissions. Circuit integrity requires a separate fire-resistance specification.
Mistake 2: Assuming Flame-Retardant Means LSZH
A PVC cable can meet a specified flame-propagation test while still containing halogens.
The two properties are different.
Mistake 3: Treating H07Z1-K and H07Z-K as Identical
They belong to different standard and insulation-temperature families.
Confirm EN 50525-3-31 versus EN 50525-3-41 and the actual datasheet.
Mistake 4: Comparing H07V-K and H07Z-K Only by Price
Both may have Class 5 copper conductors and a 450/750 V rating, but their insulation systems and fire-emission characteristics are different.
Mistake 5: Copying Another Manufacturer’s Temperature or CPR Class
A temperature, CPR class, flame category, or LSZH test result should come from the product actually being purchased.
Do not copy specifications from a similar-looking cable.
Mistake 6: Accepting a Generic Certificate
The certificate must cover the correct designation, manufacturer, product scope, and required size range.
Mistake 7: Ignoring the Cable Marking
The final cable, packaging, datasheet, certificate, DoP, and test reports should tell the same technical story.
H07Z1-K / H07Z-K Buyer Specification Matrix
| Requirement | What to Specify |
|---|---|
| Cable designation | H07Z1-K or H07Z-K |
| Product standard | EN 50525-3-31 or EN 50525-3-41 |
| Voltage | 450/750 V |
| Conductor | Copper |
| Conductor class | Class 5 |
| Size | Project-specific mm² |
| Insulation | Exact applicable halogen-free compound |
| Temperature | Confirm 70°C or 90°C according to cable type |
| Flame performance | State exact required test |
| Smoke performance | State required test/criterion |
| Halogen performance | State required test/criterion |
| CPR | Required class and DoP where applicable |
| Circuit integrity | Separate requirement if fire-resistant cable is needed |
| Color | Project-specific |
| Packaging | Coil/reel length and tolerance |
| Marking | Approved legend before production |
| Documents | Datasheet, certificate, DoP and test reports as required |
How to Write an H07Z1-K or H07Z-K RFQ
Instead of writing:
Need LSZH building wire, please quote.
Use a controlled specification such as:
Cable designation: H07Z1-K
Standard: EN 50525-3-31
Rated voltage: 450/750 V
Conductor: Class 5 flexible copper
Size: 2.5 mm²
Color: Brown / blue / green-yellow
Quantity: Specify
Packaging: 100 m coils
Flame requirement: Specify exact required test
Smoke requirement: Specify exact required test
Halogen requirement: Specify exact required test
CPR class: Specify if required
Documents: Datasheet, applicable certificate, DoP and test reports
Marking: Submit sample legend for approval before production
For H07Z-K, replace the designation and standard with the project-specified EN 50525-3-41 construction and confirm the 90°C insulation requirement.
This makes competing quotations much easier to compare.
Can H07Z-K Replace H07Z1-K?
Not automatically.
Electrically, the two products may share:
- 450/750 V rating
- Class 5 conductor
- Similar size options
- Flexible single-core construction
- Halogen-free fire-emission objectives
But substitution should still be approved against:
- Project specification
- Product standard
- Insulation type
- Dimensions
- Temperature rating
- Fire performance
- CPR requirement
- Termination
- Local installation rules
A higher temperature rating is not, by itself, proof of full interchangeability.
Can H07Z1-K Replace H07V-K?
Only when the installation specification and approvals permit the substitution.
H07Z1-K can provide a halogen-free alternative to H07V-K in appropriate protected installations, but the change affects the insulation system and may affect dimensions, handling, cost, fire documentation, and procurement requirements.
For standard protected wiring where LSZH is not required, H07V-K may remain the correct and more economical product.
Frequently Asked Questions
Is H07Z1-K an LSZH cable?
Yes, H07Z1-K belongs to the halogen-free, low-smoke single-core cable family. However, buyers should verify the exact applicable standard and supporting smoke and halogen test documentation rather than relying only on the commercial term “LSZH.”
What is the main difference between H07Z1-K and H07Z-K?
The key difference is the insulation system and associated temperature rating. H07Z1-K is generally associated with EN 50525-3-31 and a 70°C halogen-free thermoplastic construction, while H07Z-K is associated with EN 50525-3-41 and a 90°C halogen-free cross-linked construction.
Is H07Z-K fire-resistant?
Not automatically. H07Z-K is a halogen-free cable designation. Fire-resistant circuit integrity must be demonstrated by a separate applicable test if the project requires it.
Is LSZH the same as flame-retardant?
No. LSZH addresses smoke and halogen-related combustion characteristics. Flame-retardant testing evaluates flame propagation. Both properties may be required, but they are not interchangeable.
Is a flame-retardant cable fire-resistant?
No. Limiting flame propagation does not prove that the electrical circuit will remain operational during fire.
What is the difference between H07V-K and H07Z1-K?
Both use flexible Class 5 copper conductors and are commonly rated 450/750 V, but H07V-K uses PVC insulation while H07Z1-K uses a halogen-free insulation system.
What does the K mean?
In these harmonized cable designations, K identifies a flexible fine-stranded conductor construction.
Does H07Z-K always operate at 90°C?
H07Z-K specified to the applicable 90°C EN 50525-3-41 construction is designed for that conductor temperature class. Always confirm the actual manufacturer’s datasheet and certification instead of assuming a value from the cable name alone.
Does a 90°C cable automatically have a higher ampacity?
No. Final ampacity depends on conductor size, installation method, ambient temperature, grouping, terminal rating, protective device, and local electrical rules.
What documents should I request before buying LSZH building wire?
At minimum, request the exact product datasheet and the documents required by your project. These may include approval certificates, CPR Declaration of Performance, flame test reports, smoke-density reports, halogen/corrosivity reports, batch test data, and cable-marking confirmation.
Final Recommendation
H07Z1-K, H07Z-K, and H07V-K may all appear to be simple 450/750 V flexible single-core building wires, but their insulation and fire-performance boundaries are different.
Use H07V-K where a PVC-insulated Class 5 building wire is permitted.
Use H07Z1-K where the specification requires an EN 50525-3-31-type halogen-free flexible wire with the applicable 70°C insulation system.
Use H07Z-K where the specification requires the corresponding EN 50525-3-41 halogen-free cross-linked construction and 90°C temperature class.
Most importantly, do not reduce the purchase decision to three marketing words:
LSZH, flame-retardant and fire-resistant are three different technical concepts.
Before approving a bulk order, make sure the cable designation, standard, datasheet, certificate, CPR declaration where applicable, fire-test reports, cable marking, and physical sample all match.
KingForYou Cable supplies H07Z-K, H07V-K and other building and low-voltage cable products for distributors, contractors, OEM buyers, and project procurement.
For a quotation, send the cable designation, standard, conductor size, colors, quantity, destination market, packaging and required test documents through our contact page.
