Residues of hazardous waste in containers may not be subject to the hazardous waste regulations if the containers are considered RCRA-empty as defined in 40 CFR 261.7. The definition of empty depends on the type of waste and the container.
Here’s how to determine if a hazardous waste container is considered empty:
Step 1: Determine if the waste is an acute, or non-acute hazardous waste. Acute wastes are either on the P-list at 40 CFR 261.33(e), or they are on the F-list at 40 CFR 261.31 if they are designated with the hazard code of H. Containers of acute hazardous waste are considered empty if they have been triple-rinsed using a solvent capable of removing the waste. Or, they can be cleaned by another method that has been shown in the scientific literature, or by tests conducted by the generator, to achieve equivalent removal.
Step 2: Determine if the hazardous waste is a compressed gas. If so, skip to step 4.
Step 3: For non-acute hazardous wastes that are not gases, the container is empty if two steps are taken. First, all wastes have been removed that can be removed using the practices commonly employed to remove materials from that type of container, such as pouring, pumping, and aspirating. Second, the container cannot have more than 1 inch of residue or 3% residue by weight. If the container has a capacity over 119 gallons, the percentage of residue allowed is reduced to 0.3%.
Step 4: If the hazardous waste is a compressed gas, such as in an aerosol can or compressed gas cylinder, the container is considered empty when the pressure inside approaches atmospheric pressure.
Residue remaining in containers that meet the definition of empty is not subject to the hazardous waste regulations at 40 CFR 261 and 262 through 268, 270, and 124. However, if RCRA-empty containers will be shipped off-site, the DOT hazardous materials transportation regulations could apply to the shipment if there is any residue remaining in the containers.
