Definition of "Cleaned and Purged"

This is in response to your letter dated July 28, 1995, requesting clarification of the term "cleaned and purged" as it applies to bulk containers such as "roll-off" type metal boxes and sift-proof metal boxes under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180).

For the purposes of the HMR, "cleaned and purged" means no residual material and no residual vapor remaining in the interior of a container. The methods used are intentionally not defined because they vary greatly depending on the nature of the hazardous material and the type of packaging. In some instances, a packaging can be totally emptied of hazardous material, including residue, without undergoing a cleaning process, and may be considered "cleaned and purged". In other instances, an active cleaning process may be necessary to purge a packaging of hazardous residue. The scenario presented in your letter involving a Class 9 "Hazardous waste, solid, n.o.s." material appears to meet the definition of "sufficiently cleaned of residue and purged of vapors to remove any potential hazard" provided the residue remaining on the interior container walls no longer meets any of the hazard class definitions of the HMR.