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As digital buildings continue to bring disparate systems together on one physical infrastructure, a wide range of devices – from LED lighting fixtures to surveillance cameras – call for network connectivity to offer the most benefit. Oftentimes, this connection may need to occur within a building’s plenum space (the separate space provided for air circulation): above a drop ceiling or under a raised floor, for example.


If the systems connect within your building’s plenum space, the cable and connectivity components used inside the plenum space must follow certain fire protection regulations in accordance with the National Electrical Code (NFPA 70), including a rating for smoke and heat release in air-handling spaces: UL 2043, Fire Test for Heat and Visible Smoke Release for Discrete Products and Their Accessories Installed in Air-Handling Spaces.

What is UL 2043?

The goal of UL 2043 is to regulate the materials of components used in plenum spaces to protect property and lives from damage caused by fire, as well as smoke that results from fire. This often includes restricting smoke or fire spread within a building – in this case, reducing the potential for ignition and combustion of elements that may be located within the plenum space.

Products that meet UL 2043 requirements must be made of materials that are noncombustible or have specific surface burning and smoke characteristics to help prevent smoke and fire spread. This allows safe remote power delivery and connectivity for IP-enabled devices with little or no additional fire barrier (conduit, baffles, etc.).

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UL 2043 Markings: What to Look For

If you’re looking for cable and connectivity components that comply with UL 2043, make sure they have the UL certification mark either on the product itself or on the container/packaging. Look for:

  • The UL symbol
  • The word “classified”
  • A control number

UL 2043 Connectivity Components

Belden’s new connectivity system, REVConnect, recently passed 2043 testing, allowing it to be safely installed in plenum spaces. REVConnect enables reliable, easy and versatile terminations that support IP convergence in digital buildings and other applications, with up to 100W of supported PoE++ performance for everything from high-definition displays, LED lighting, security cameras and HVAC controls to wired LAN. Using a single termination method, REVConnect’s universal termination core can be used for Category 5e through Category 6A RJ45 connections.

If you’re having trouble finding the UL 2043 connectivity solutions you need, Belden also offers a direct-connect strategy that can bring connectivity out of the plenum space to avoid the need for UL 2043 components.