Black polyethylene jackets on outdoor cables are used for:

• A. Sunlight and Moisture Resistance
• B. Abrasion Resistance
• C. High Tensile Loads
• D. Appearance

Answer: (A)

The jacket is chosen for outdoor cables to protect against two big environmental threats: sunlight and moisture. Polyethylene by itself resists water, but sunlight—especially UV radiation—can break it down over time. Adding carbon black pigment to the jacket absorbs UV light and helps dissipate that energy, slowing polymer degradation and extending the cable’s life in sunny outdoor conditions. The black color is a practical indicator of this UV stabilization and moisture-protective barrier, which is why it’s used outdoors. While abrasion resistance and strength matter in other contexts, they aren’t the primary reason for a black polyethylene jacket outdoors, and appearance isn’t the driving factor either.