That's a great and practical question! As someone who's managed public spaces, I've seen my fair share of overstuffed bins. There isn't a single universal number, as it depends heavily on the bin's design, plastic quality, and thickness. However, a typical standard-sized (around 50-60 gallon) public plastic waste bin is generally engineered to hold roughly 150 to 250 pounds (68 to 113 kg) of distributed weight before risk of cracking.
The key phrase is "distributed weight." These bins handle bagged general waste well. Problems start with point loads—like a heavy, compacted bag of construction debris thrown in, or someone overzealously compacting the trash. Temperature is a big factor too; plastic becomes brittle in freezing cold and softer in extreme heat, both reducing its strength.
Most cracks begin at stress points: the rim, handles, or wheel mounts. A bin rarely fails from a single heavy load; it's usually fatigue from repeated overfilling or improper use (like dragging when full). To maximize lifespan, avoid compacting waste forcefully, don't overfill beyond the rim, and keep heavy, dense materials like bricks or concrete out. If you need a bin for heavy industrial waste, look for specifically rated commercial models with thicker walls and reinforced bases.