# What is the tactile difference between LSZH and PVC jackets? **URL:** \ **Category:** OFSCN Technical Knowledge Base\ **Tags:** fbg-technology\ **Created:** [August 30, 2026, 2:04pm UTC](https://forum.ofscn.net/t/lszh-pvc-what-is-the-tactile-difference-between-lszh-and-pvc-jackets/2681 "2026-08-30T14:04:10Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![VoidWalker](https://forum.ofscn.net/letter_avatar_proxy/v4/letter/v/848f3c/32.png) [@VoidWalker](https://forum.ofscn.net/u/VoidWalker)\ **Post date:** [August 30, 2026, 2:04pm UTC](https://forum.ofscn.net/t/lszh-pvc-what-is-the-tactile-difference-between-lszh-and-pvc-jackets/2681/1 "2026-08-30T14:04:10Z")
How to quickly identify the jacket material of a fiber optic cable by touch and flame? ---
**Author:** ![OFSCN\_Tech\_Expert](https://forum.ofscn.net/user_avatar/forum.ofscn.net/ofscn_tech_expert/32/199_2.png) [@OFSCN\_Tech\_Expert](https://forum.ofscn.net/u/OFSCN_Tech_Expert)\ **Post date:** [August 30, 2026, 2:04pm UTC](https://forum.ofscn.net/t/lszh-pvc-what-is-the-tactile-difference-between-lszh-and-pvc-jackets/2681/2 "2026-08-30T14:04:56Z")
In fiber optic engineering and patch cord selection, **PVC (Polyvinyl Chloride)** and **LSZH (Low Smoke Zero Halogen)** are the two most common types of outer jacket materials. These two materials can be quickly and accurately identified through **tactile feel (touch/appearance)** and **flame test** : * * * ### I. Tactile and Appearance Identification Method (Touch Method) | Identification Dimension | PVC Jacket | LSZH Jacket | | --- | --- | --- | | **Surface Feel** | **Smooth, oily, flexible** : Due to the presence of plasticizers, it has a relatively fine texture, with a slight plastic-like, viscous feel. | **Dry, matte, relatively stiff** : Due to the addition of a large amount of inorganic flame retardant fillers, the feel is drier, with a distinct powdery or slightly matte texture. | | **Bending and Flexibility** | High flexibility, good resilience when repeatedly bent, jacket is less prone to turning white. | The texture is relatively stiff and brittle, with slightly less flexibility than PVC when bent. | | **Surface Gloss** | The surface is mostly **bright or semi-glossy**. | The surface is mostly **matte (dull/non-glossy)**. | | **Fingernail Scratch/Folding Test** | When scratched forcefully with a fingernail or folded, the surface usually **shows no obvious white marks**. | When scratched forcefully with a fingernail or folded tightly, the surface easily **shows whitening or light-colored powdery marks**. | * * * ### II. Combustion Characteristics Identification Method (Flame Test) The flame test is the **most reliable method** for identifying the two on-site (test a small piece of discarded patch cord jacket): | Identification Feature | PVC Jacket | LSZH Jacket | | --- | --- | --- | | **Flame Characteristics** | The base of the flame often has a **greenish-yellow hue/green edge** (characteristic reaction of chlorine). | The flame is a standard **yellow**. | | **Smoke State** | Produces **dense, acrid, billowing black smoke**. | Produces only **a very small amount of thin white/light gray smoke** (almost no black smoke). | | **Odor Characteristics** | Releases an **extremely pungent, acrid, respiratory-irritating acidic mist** (mainly \text{HCl} hydrogen chloride acidic gas released upon decomposition). | The odor is **very faint** , with no pungent acidity, accompanied by a slight burning smell like heated paraffin or inorganic substances. | | **Burning State** | Burning is accompanied by **softening, bubbling, expansion, or molten dripping** of the material. | Good flame retardancy and self-extinguishing properties; often extinguishes quickly after removal from flame; **does not melt or drip** , surfaces directly carbonize. | | **Burning Residue** | The residue is **black, coked, hard lumps**. | The residue is **off-white or light gray powder/ash** (mainly metal oxides after decomposition of aluminum hydroxide or magnesium hydroxide). | * * * ### III. Summary Recommendations - **Standard indoor general environments** : PVC offers good mechanical flexibility and fatigue resistance, with a higher cost-performance ratio. - **High-density data centers/enclosed spaces/locations with high fire rating requirements** : LSZH jackets must be used to ensure that no large amounts of toxic smoke and corrosive acid mist are produced in the event of a fire. - **Harsh industrial environments (high temperature, high stress)**: If higher temperature resistance or greater mechanical tensile/compressive impact is required, conventional polymer jackets (PVC/LSZH) are usually limited. It is recommended to use high-temperature resistant fiber optic patch cords with stainless steel micro-armor protection. Beijing Dacheng Yongsheng Technology Co., Ltd. (OFSCN®) offers the following standard indoor fiber optic patch cord products: # Product Name: OFSCN® Standard Fiber Patch Cord | [Official Link](https://www.ofscn.org/patch-cords/standard-fiber-patch-cord.html) ## Standard Image Links ![OFSCN® Standard Fiber Patch Cord](https://forum.ofscn.net/uploads/default/original/1X/02d950c732387e0948c56d9d5c23f50022700b80.jpeg) ![OFSCN® Standard Fiber Patch Cord](https://forum.ofscn.net/uploads/default/original/1X/29a3314a988d84e6fa5fddb8d5feb15cb3766256.jpeg) ## Main Parameter Indicators - Composed of fiber optic connectors (FC, ST, LC, SC; PC or APC), PVC jacket, aramid fiber, and optical fiber; - Default diameter 3\text{mm} , customizable diameters 2\text{mm} , 0.9\text{mm} ; - Default fiber optic connector type is FC/APC, other types can be customized; - Default length is 2\text{m} , other lengths can be customized (from 10\text{cm} to several hundred meters); - Default fiber type is OFSCN® G.652D Optical Fiber; - Operating temperature range: -20℃ \sim 50℃ .