That's a great question that gets to the heart of urban durability. The plastic used on most modern city trash cans is specifically formulated to withstand UV rays, but it's a constant battle. Over time, even the best plastics will show signs of degradation from prolonged sun exposure.
Typically, these bins are made from high-density polyethylene (HDPE) or polypropylene, with added stabilizers and pigments. Carbon black is a common and highly effective additive that acts like sunscreen, absorbing UV radiation before it can break down the polymer chains. You'll notice most public bins are dark colors for this reason.
However, without these protections, UV rays cause photodegradation. They break the long molecular chains in the plastic, making it brittle. You might see fading, a chalky surface, or cracks—especially on the south-facing side of the bin. In extreme cases, the plastic can become so weak it shatters from a simple impact.
Municipalities choose these UV-stabilized plastics because, despite gradual weathering, they still outperform metal in resisting corrosion and dents, and are lighter and cheaper. The lifespan is a balance of material science and cost. So, while they don't last forever, the plastic on your city's trash cans is fighting the sun's rays much better than ordinary plastic would. Regular maintenance and replacement of heavily degraded units are just part of the urban lifecycle.