That's a great question, and one that city planners and public works departments think about a lot. The short answer is: modern plastic urban trash bins are surprisingly resistant to UV rays, but it's not a forever guarantee. They're specifically engineered for it.
Unlike basic plastics that become brittle and fade quickly, bins made for municipal use are typically from high-density polyethylene (HDPE) or polypropylene. The key is in the additives. During manufacturing, UV stabilizers and pigments (like carbon black) are mixed into the resin. These act as a sunscreen, absorbing and scattering the sun's radiation to protect the plastic's polymer chains from breaking down.
You'll notice that most public bins are dark colors—black, dark green, or dark gray. This isn't just for aesthetics; darker pigments are much more effective at blocking UV penetration. A black bin will generally outlast a bright red or light gray one in direct, constant sunlight.
So, what happens over time? Even with stabilizers, prolonged exposure (think 5-10 years in a sunny climate) will cause gradual effects. You might see surface fading or a slight chalky feel. However, this is usually cosmetic long before it affects structural integrity. The bin won't just crumble; the additives significantly slow the process, ensuring it remains functional and safe for years.
In summary, while no plastic is completely immune, today's urban trash bins are highly UV-resistant. Their design prioritizes long-term outdoor durability, meaning fading is more likely than catastrophic failure. Proper material choice and those built-in stabilizers make them a reliable fixture in our parks and streetscapes.