That's an excellent and very practical question! It shows you're thinking about the long-term durability of public infrastructure. The short answer is: it depends entirely on the specific bin model and the purchasing specifications of your city's public works department.
Many modern urban trash bins, especially those designed for long-term outdoor use, are indeed made from UV-stabilized plastics. Manufacturers often use materials like polyethylene (HDPE or LLDPE) with added UV inhibitors. These additives act like sunscreen for the plastic, absorbing or reflecting the sun's ultraviolet rays to significantly slow down the degradation process that causes fading, brittleness, and cracking.
However, not all bins are created equal. Some lower-cost or older models may use untreated plastic to save on initial expenses. You can often spot a non-stabilized bin after a few years—it will appear chalky, faded to a lighter color, and may have become brittle.
If you're curious about a specific bin in your area, your best bet is to contact your local municipality's sanitation or parks department. They can provide details on their procurement standards. For your own purchases, always check the product specifications for terms like "UV-stabilized," "UV-resistant," or "weatherproof" to ensure you get a bin that maintains its color and strength for years.