P and U-Listed Wastes

P-listed and U-listed wastes are discarded commercial chemical products. The chemicals being disposed of may be unused chemicals that have spilled or been discarded because they no longer are of use. To be P- or U-listed, a waste must meet all of the following conditions:

• The waste contains one of the chemicals on the P or U list.
• The chemical in the waste is unused.
• The chemical in the waste is the form of a commercial chemical product.

In the RCRA regulations, a commercial chemical product is defined precisely as a chemical that meets all of the following criteria:

• 100 percent pure (the chemical is the only chemical constituent in the product)
• Technical grade (the formulation, although not pure, contains a grade of purity that is in general usage)
• The sole active ingredient in a chemical formulation (the chemical is the only active ingredient accomplishing the purpose of the formulation)

P-listed wastes and U-listed wastes are both types of discarded commercial chemical products that are considered hazardous. The P-list and the U-list may both be found in the RCRA regulations at 40 CFR 261.33.

To learn more about RCRA safety standards visit our RCRA Refresher Online Training web page.