Most household junk and building debris can go in a dumpster. The limits come from King County's disposal rules and from the facility that receives the load.
Hazardous waste, liquids, paint, solvents, fuel, and asbestos can't go in a standard dumpster. King County takes household hazardous waste at collection sites in Auburn, Factoria, and Seattle, and at its traveling Wastemobile events.
Electronics like TVs, computers, monitors, and laptops can be recycled for free through Washington's E-Cycle program, so keep them out of your load.
King County transfer stations also require some items to be sorted for recycling instead of thrown away, including cardboard, clean wood, scrap metal, and yard waste. Mixed construction debris has its own route, covered below.
If you're unsure about an item, ask your account manager before you load it.