Unused or unopened chemicals will meet the definition of a listed hazardous waste if they appear on
one of two lists. The U-list contains materials that are hazardous due to their toxicity. The P-list
contains materials that are hazardous because they are acutely toxic. These lists only apply to unused
materials that have one of the listed chemicals as the sole active ingredients. The list also applies to spill
cleanups of these unused materials. The complete U and P lists are included in Appendix A and B of this
manual.