CLASSIFICATION OF WASTES

In the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) no clear reference is made to wastes.
However the UN SubCommittee of Experts on GHS has agreed to cooperate with the Open Ended Working Group of the Basel Convention in order to come out with a proposal for wastes classification on the basis of GHS.

I don’t see any problem in simply stating that wastes have to be classified in accordance with GHS.

First of all I would like to remind that, for transport, wastes are classified according to the criteria for mixtures and then in accordance with GHS.
Moreover, looking to Basel Convention, the list of hazardous characteristics in Annex III (based on transport regulations for Codes H1 to H8) can be easily revised making reference to GHS.

The real problem is that sometime it is very difficult to classify wastes, due to the uncertainties on the real content of hazardous substances and on their concentration and also because (mainly for physical hazards) no clear criteria have been developed for mixtures.

In conclusion:
a) criteria for mixtures (physical hazards) need to be investigated
b) a conservative approach for classifying wastes with unknown content or concentration could be considered (see, for instance, the discussion going on at the Joint Meeting ADR/RID/ADN)