Space is not the place to put waste, as it turns pretty much anything into a high-velocity projectile capable of causing incredible damage.
Space isn't as spacious as it should be; it's full of space debris, small amounts of scrap, trash, and machinery that humans have abandoned to Earth's orbit. The ISS has cataloged about 500,000 of these small pieces and they hurtle around our planet at about 15,000mph. Or 14.17 g-force. Or 24,140kph.