The answer to the first question hinges on the issue of point of generation (POG). A material becomes a waste when the owner or operator decides that it cannot be used for its original intended purpose. A good example would be a can of paint. As long as there is a legitimate use for the paint and the paint is still usable as a paint, it is not a waste. So if you can find some one to use the paint in a legitmate manner, you won’t have to worry about it. But if you decide that you want to dispose of it, it becomes a waste. Another example would be a jar of pure chemical on your laboratory shelf. If the shell life of that chemical has been exceeded (it cannot be used for its original intended purpose), it becomes a waste.
Another example: You may have a very hazardous chemical in a chemical reactor where you are brewing your product, you do not have a waste as long as that hazardous chemical stays inside the reactor as part of your manufacturing process. But once you take that hazardous chemical out of the reactor and you have no further use for it, you will have generated a waste at that point. That’s you POG.
Once you have a waste, then you have to determine if it is hazardous. Does it exhibit any of the four hazardous waste characteristics (ignitability, corrosivity, reactivity and toxicity)? Has the waste been listed by EPA?