On June 23, 2006 a new official Mexican norm (NOM) NOM-052- SEMARNAT-2005, was issued, which will take effect on September 21, 2006. The NOM establishes characteristics and procedures for identifying, classifying and listing all hazardous waste, notwithstanding their emission, treatment or final destination. The NOM contains a new section of definitions applicable to all environmental matters, five classification listings for hazardous waste, two tables and an exhibit. The NOM classifies hazardous waste based on five listings, distinguishing such as follows: i) specific sources (Code E); ii) non-specific sources (Code NE); iii) waste resulting from disposal of chemical products outside of specifications or shelf life (Code H, Acutely Toxic); iv) hazardous waste resulting from disposal ofchemical products outside of specifications or shelf life (Code H, Chronic Toxic Substances); and v) waste subject to specialhandling conditions (Code RP). It is important to note that the NOM establishes a new procedure for obtaining a determinationof hazardousness, resulting from regulation in the management and destruction of some waste. The new NOM allows a wastegenerator to determine how dangerous a particular waste is using the CRIT method, or simply basing such on their knowledgeand experience. In addition, the new NOM permits one to maintain current practices relating to management of hazardouswaste in Mexico. Three gray areas remain, particularly as a result of a delay in the promulgation of new regulations to theGeneral Law for the Prevention and Treatment of Materials as part of the management of waste in general.