Most construction debris and household junk can go in. The limits come from California's trash rules and from the county landfill.
CalRecycle keeps a list of waste banned from the trash. It includes all batteries, fluorescent tubes, paint, solvents, antifreeze, motor oil, and tires. Electronics like TVs, monitors, computers, and microwaves are banned too.
Some building materials need special care. Treated wood, such as old fence posts and deck lumber, must be handled as hazardous waste in California. Asbestos, found in some older siding, flooring, and roofing, can't go in a dumpster.
Hazardous waste, liquids, paint, solvents, fuel, and propane tanks can't go in a standard dumpster either.
If you're not sure about an item, ask your account manager before you load it.