Fiber Cable Maintenance

Cleaning Procedures for Fiber Cable Connections

The most prominent cause of fiber-optic dropped packets or network outages comes from dirty or comprised fiber connections. If a particle of dust, lint, oil, or any other dirt gets on the end of the connector, it will interrupt the signal being sent. These seemingly small particles can throw a hiccup in the data transfer capabilities of your network, leading to costly network failures and downtime. It is important to address why clean environments and proper cleaning maintenance of your fiber transceivers and cables is necessary for the health of your network.

Signs a fiber connection may be contaminated

Performance Monitoring

Signs of contamination usually exhibit themselves in the form of performance degradation

Signal Loss​
If you notice a loss of signal strength, this could be a sign of contamination. This can be monitored by viewing the Rx Power (Receiving Power) through the system.
Error Rates
Increased error counts, such as input errors, CRC errors, or packet loss can also indicate possible contamination or other issues.
Link Flapping
If the connection flaps between connected and disconnected, this is also a sign of possible contamination.

Scope Inspection of Contaminated
LC Fiber Connection

Cable Inspection & Diagnosis

Examining a fiber core with an Integrated Fiber EndFace Inspector can help identify when damage or contaminates are effecting the throughput of light in the fiber.

Why is maintenance important?

In order to maintain optimal performance in a fiber network, it is paramount that fiber never be left exposed. Maintaining clean connections ensures your cables will perform to their proper specifications. Transceiver connectors and fiber cables should always be plugged in or covered with a dust cap in order to protect the fiber core. Any contamination in a fiber connection can cause failure of the component or the whole system overall. Microscopic dust particles that partially or completely block the fiber core generate strong back reflections which in turn cause instability in the laser system.

If a fiber cable was cleaned and properly inspected upon original installation, there are still ways in which the connectors can acquire contamination over time, even if the cable has never been removed. Here are some potential causes:


In data centers or cabinets with active cooling, the airflow intended to cool equipment can inadvertently introduce or move around dust and particles, leading to contamination.

Wear and Tear

Over time, connectors may degrade or wear out due to constant thermal cycling, causing them to release minute particles, which can contaminate the end-face.


If there are temperature fluctuations in the environment where the connectors are located, condensation can form on the connector end-face, leading to potential contamination.


If the connectors are placed within an enclosure or patch panel, connections within the same enclosure can introduce contaminants every time they are accessed, plugged, or unplugged.

Airborne Contaminants

Dust and other particles in the air find their way into even secure environments. Depending on the cleanliness of the environment, small amounts of dust or other airborne particles can settle on exposed connectors.

Microscopic Particles

Not all contaminants are easily visible to the naked eye. Minute particles from the surrounding environment can settle on connectors. These might have been missed during the original inspection or could have been introduced later.

Degradation of Materials

Over time, the materials used in the connectors, or nearby components, might degrade, releasing tiny particles that can contaminate the fiber optic end-face.

Diagnosing Connector Contamination

Visual Inspection

  • Microscope Examination
    Use an inspection microscope, ideally with at least 200x or 400x magnification, to inspect the end-face of the connector. This will allow you to see contamination like dust, dirt, oil, or other debris.
  • Connector Health
    Check the physical condition of the connectors. Visible wear, cracks, or damage can be sites of contamination.

Physical Environment Monitoring

  • Environment Examination
    If the environment where the cable operates has recently become dirtier or dustier, there is an increased likelihood of contamination. Keeping tabs on environmental changes can give clues about potential contamination sources.

Optic Baseline Monitoring

  • Compare Against Good Cable
    If you suspect contamination, and the visual inspection or tools don't provide a clear answer, try swapping the suspect cable with a known good one. If the issues resolve after the swap, it is possible that the original cable was the problem.

How To Clean a Fiber Cable

Gather Cleaning Supplies:
• Lint-free cleaning swabs or sticks, specifically designed for fiber optics.
• Non-abrasive cleaner (air duster)
Dry Cleaning (Stay away from alcohol-based cleaning sticks)
  • Open the dust cover or remove the dust plug from the module
  • Use a non-abrasive cleaner (canned air) to remove any dirt or debris.
  • Insert a lint-free cleaning stick of the appropriate size (2.5 mm or 1.25 mm) and turn clockwise. Dry cleaning is recommended. Do not use alcohol-based cleaning sticks!
  • Remove the cleaning stick, close the dust cover or reinsert the module’s dust plug. Always keep the dust cover or dust plug inserted in the module when not in use.
  • Always make sure that the connector that will be plugged into the module is also clean before connecting it to the module to prevent cross-contamination
  • This procedure should always be followed when connecting or disconnecting fiber to or from the module.
  • Inspect After Cleaning
    After cleaning, it's a good practice to inspect the connector end-face using a fiber inspection microscope. This ensures that the cleaning process was successful and that there's no residue or other contaminants left behind.
    Safety Precautions
    • When working with optical modules, make sure you're in an area equipped for ESD (electro-static discharge) protection and follow all necessary safety measures.
    • Before handling any module, confirm that it's powered down and treat each module delicately.
    • Only use Clean Dry Air (CDA) or a trusted source of canned compressed air.
    • While using compressed air, keep the can in a vertical position. Angling it might cause unwanted liquids to be discharged with the air.
    Protective Caps
    After cleaning, if the transceiver will not be used immediately, ensure you place a protective cap over the connector to prevent future contamination.
    Regular Cleaning and Inspection
    Cleaning your cables can significantly extend their lifespan and ensure consistent and reliable performance. Proper care and handling are essential, given the sensitive nature of optical connections.

    General Guide For When to Clean

    • Installation
      Fiber cables should be inspected at the time they are installed. The installation inspection helps ensure there is no contamination present.
    • After Installation
      After installation, the cables should be inspected to ensure they were not contaminated during the installation process.
    • Regular Inspections
      Following installation, regular inspections are key. The specific timeline for these inspections can depend on the operating environment. For instance, if the cables are exposed to harsh environmental conditions (e.g., dust, heat, humidity), more frequent inspections may be necessary.
    • Prior to Reconnecting
      If a cable has been disconnected for any reason, the cable should both be inspected and cleaned before it is reconnected.
    • Scheduled Maintenance
      As a part of scheduled maintenance, fiber optic cables should be inspected and cleaned. This is often done annually, but the frequency may be adjusted based on the environment and how critical the network is to operations.

    Cable Maintenance Products

    Fiber Connector Cassette Fiber Cleaner- APC/UPC LC, SC, ST, FC, MT, MU, E2000 (500+ Cleans)

    Reel-type cleaners quickly and effectively clean a variety of connectors. Reel-type cleaners are a safe cleaning option without the need for alcohol, which can be toxic and flammable. They have refillable cleaning tapes making them ideal for lab, assembly lines and field use.

    For Fiber Connectors (LC, SC, ST, FC, MT, MU)

    • 1
      Have cleaner and desired cabling ready to use together
    • 2
      While holding cable with one hand, use other hand to firmly secure the cleaner and press down the release to open position
    • 3
      Run cabling in 1 direction toward yourself (1 swipe per cable, do not run multiple times to avoid contamination)
    • 4
      Release the latch to close the exposed cleaning material
    • 5
      Repeat procedure for each cable needed
    LC/MU Simplex Click Pen Fiber Cleaner (800+ Cleans)

    Designed for cleaning LC and MU type connectors, this fiber cleaner can easily remove dirt, dust, oil and grease from an optical fiber adaptor. With the ability to each into the entire area within the connector, it makes cleaning of the ferrule endface a simple task with the push of a button.

    For Fiber Connectors (LC/MU):

    • 1
      Remove the top of outer cap of LC/MU Simplex Cleaner (with attachment still on cleaner)
    • 2
      Align connector to fit into cleaner
    • 3
      Press cleaner until click is heard, then release
    • 4
      Repeat for each fiber cable connection needed

    For Transceiver / Fiber Patch Connection (LC/MU)

    • 1
      Fully remove outer cap of LC/MU Simplex Cleaner
    • 2
      Press cleaner until click is heard, then release
    • 3
      Repeat as needed per LC Transceiver / Fiber Patch connection
    MTP/MPO Click Pen Fiber Cleaner (500+ Cleans)

    This push-type cleaner is specifically designed for the cleaning of ferrule end-faces in MTP/MPO adapters. With the ability to clean all 8/12/24 fibers simultaneously it is a time and cost efficient tool for the maintenance of fiber cables. This cleaner can clean both exposed jumper ends as well as connectors embedded in the adapter.

    For Fiber Connectors (MTP/MPO)

    • 1
      Keep attachment on device
    • 2
      Align connector to fit into cleaner
    • 3
      Press cleaner until click is heard, then release
    • 4
      Repeat for each fiber cable connection needed

    For Transceiver / Fiber Patch Connection (MTP/MPO)

    • 1
      Fully remove outer cap of MTP/MPO fiber cleaner
    • 2
      Press cleaner until click is heard, then release
    • 3
      Repeat as needed per MTP/MPO transceiver / Fiber Patch connection