Valerie Kuntz: First, determine the actual substances contained in recycled materials. Ideally you could request information from your suppliers about the supply stream for these materials. Alternatively, you may want to declare for any substances likely to be included throughout the life cycle of the source materials you are using (based on the assumption that the substance is likely to be found in the recycled material as well, even if it has been diluted by other additions). Testing is another option, but keep in mind that it will only establish the contents of the specific batch of the material tested. As a general best practice, research and understand any declarable substances likely to exist in your recycled material throughout its life cycle, and consider declaring for any of these that are declarable under the regulation(s) in question. Specific concentrations are more difficult to establish, and may depend on factors earlier in the recycled material’s life cycle.