# What are "anti-fungal" requirements? **URL:** \ **Category:** OFSCN Technical Knowledge Base\ **Tags:** fbg-technology\ **Created:** [August 7, 2026, 3:29pm UTC](https://forum.ofscn.net/t/what-are-anti-fungal-requirements/2512 "2026-08-07T15:29:27Z")\ **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 7, 2026, 3:29pm UTC](https://forum.ofscn.net/t/what-are-anti-fungal-requirements/2512/1 "2026-08-07T15:29:27Z")
Would jumper surfaces grow fuzz in a tropical rainforest or humid tunnel, affecting performance? ---
**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 7, 2026, 3:30pm UTC](https://forum.ofscn.net/t/what-are-anti-fungal-requirements/2512/2 "2026-08-07T15:30:10Z")
In tropical rainforests or humid tunnels, mold/fungus growth on the surface of fiber patch cords can indeed affect optical performance and compromise the mechanical integrity and lifespan of the fiber optic system, especially in environments with high humidity (relative humidity frequently reaching \text{RH} \> 85\% ) and suitable temperatures (20^\circ\text{C} \sim 35^\circ\text{C}). * * * ### I. Mold Growth Mechanisms and Their Impact on Fiber Patch Cord Performance #### 1. Physical and Chemical Degradation of Jacket Materials Standard fiber optic patch cords typically use polymeric materials such as polyvinyl chloride (PVC), low-smoke zero-halogen (LSZH), or certain polyurethanes (PU) for their outer jackets. If the material formulation contains low-molecular-weight plasticizers or fatty acid additives that are readily utilized by microorganisms, mold mycelia can adhere and proliferate using these as nutrients: - **Structural Damage** : Through metabolic processes, mold secretes acidic and enzymatic products that degrade long polymer chains, leading to discoloration, stickiness, embrittlement, cracking, or even peeling of the outer jacket. - **Microbending Additional Loss** : Non-uniform corrosion of the jacket or localized changes in internal stress can cause uneven pressure on the internal optical fibers, resulting in micro-scale bends (microbends) that induce additional optical signal attenuation. #### 2. Contamination of Fiber Connector End-faces and Increased Loss - **Optical Path Blockage** : When mycelia spread along the patch cord surface to the fiber connector end-faces (e.g., ceramic ferrules of FC, SC, LC connectors), the mycelia and their byproducts can directly obstruct the fiber core’s transmission path (typically only about 9\ \mu\text{m} in diameter for single-mode fibers). - **Sharp Increase in Loss** : End-face contamination leads to a drastic increase in insertion loss (Insertion Loss) and deterioration of return loss (Return Loss), potentially causing localized thermal damage to the end-face due to optical power absorption. * * * ### II. Anti-fungal Requirements in Engineering For transmission cables and sensor components in harsh environments, international and domestic standards (such as GB/T 2423.16, GJB 150.10A, IEC 60068-2-10) stipulate stringent “anti-fungal testing” specifications: - **Fungal Growth Rating** : After 28 days of incubation in a fungal growth chamber, the fungal growth rating must be Level 0 (no visible mycelial growth under a microscope) or Level 1 (not visible to the naked eye, only sparse mycelia visible under a microscope). - **Selection of Anti-fungal Materials** : Priority is given to inorganic all-metal encapsulated structures or high-density polyethylene (PE) / polyimide materials with extremely high anti-fungal ratings to completely cut off the nutrient source for mold. * * * ### III. OFSCN® Solutions for Humid and High Mold Risk Environments For extreme environments such as tropical rainforests and humid tunnels, Beijing Dacheng Yongsheng Technology Co., Ltd. (OFSCN®) offers protective fiber optic patch cord products based on seamless stainless steel tubes and all-metal armored structures, which physically prevent organic mold growth: 1. **[OFSCN® 2.0mm Steel Wire Rope Fiber Optic Patch Cord](https://www.ofscn.org/patch-cords/strong-02.html)** This product features an all-metal encapsulated structure composed of a 0.6mm galvanized steel wire rope and a 1.0mm seamless stainless steel tube. The exterior is free of organic plastic jacketing, providing protection entirely through metal materials. It offers no nutrient source for mold growth, effectively solving the mold issue in humid tunnels and rainforest environments. 2. **[OFSCN® 2.0mm Micro Steel Armored Fiber Optic Patch Cord](https://www.ofscn.org/patch-cords/strong-01.html)** Incorporates a 0.6mm seamless stainless steel tube for protection, offering excellent resistance to moisture ingress and high compressive strength, effectively preventing increased attenuation of internal optical fibers in humid conditions. 3. **[OFSCN® 3.0mm Steel Wire Rope Fiber Optic Patch Cord](https://www.ofscn.org/patch-cords/strong-03.html)** Combines a seamless stainless steel tube with a weather-resistant, high-density PE outer jacket. This design provides exceptional tensile and compressive strength while offering superior resistance to mold and humid heat.