Any person acquiring a manufacturer, or brand, or who has acquired a manufacturer, or brand, shall have all responsibility for the acquired company's CEPs, including CEPs manufactured prior to July 1, 2006, unless that responsibility remains with another entity per the purchase agreement and the acquiring manufacturer provides ecology with a letter from the other entity accepting responsibility for the CEPs. Cobranding manufacturers may negotiate with retailers for responsibility for those products and must notify ecology of the results of their negotiations.