Containers of acutely hazardous waste, or pesticides marked with danger or warning labels, must be rinsed at least three times with water or solvent, depending on the original contents. You must then reuse or properly dispose of the rinse water. Store your empty, covered containers in an area protected from the weather. Rain and melted snow could collect inside a container you thought was empty and create a large volume of potentially hazardous waste. For instance, under the Uniform Fire Code, an empty container has no residual hazardous materials or vapors.
Regulatory requirements vary greatly.
It is best to contact the appropriate authorities before sending containers off-site. Check page 4 to find the phone number you can use to reach an Ecology hazardous waste specialist. My container is empty. Reuse or recycle it. The Industrial Materials Exchange Catalog lists companies that accept and redistribute empty drums.