That's a great question and a very practical concern for city planners, property managers, and homeowners alike. The short answer is: it depends heavily on the quality of the plastic and the additives used, but most modern municipal bins are designed to resist fading for several years.
Plastic trash cans fade due to photodegradation, where ultraviolet (UV) rays from the sun break down the chemical bonds in the plastic and the color pigments. Lower-quality, thin plastics with basic dyes can show significant fading, brittleness, and cracking within a single season of intense sun exposure.
However, higher-grade polyethylene bins—commonly used in urban settings—are often manufactured with UV inhibitors or stabilizers mixed directly into the resin. These additives act like sunscreen, absorbing or scattering UV radiation before it can damage the plastic's structure. You'll find that bins labeled as "UV-protected" or "for all-weather use" perform much better. Darker colors like forest green, black, or dark brown generally hide fading better than vibrant reds or bright blues, though the pigment quality is the true deciding factor.
With proper materials, a good-quality plastic trash can should maintain its color integrity for 3-5 years even in direct, all-day sunlight. After that, you might notice a gradual lightening or a chalky surface texture. To maximize lifespan, occasional cleaning to remove abrasive grime and, if possible, occasional rotation to vary sun exposure can help.
So, while no plastic is completely immortal under the sun, today's engineered urban trash cans are surprisingly resilient against fading, thanks to advanced UV-resistant formulations.