EPR provides a model that can guide private firms, community developers and surrogate regulators (like eco-labelling programmes). But it is ultimately essential that economy-wide product stewardship be mandated by government, levelling the playing field for everyone. Perhaps the most well-known proposal for such a comprehensive system comes from Michael Braungart, a chemist who was formerly head of Greenpeace Germanys chemistry department, who is now working with eco-architect William McDonough in McDonough Braungart Design Chemistry (MBDC). In the early nineties, Braungarts Environmental Protection Encouragement Agency proposed a system which received widespread attention, particularly through Paul Hawkens The Ecology of Commerce (Hawken, 1993). Braungarts "Intelligent Product System" (IPS) is based on the classification of products into three categories: Consumables, Products of Service (or durables), and Unmarketables. Consumables are products which are meant to be completely consumed in one uselike food or soap powder. They must be completely safe to be absorbed by the natural environment. Products of Service are things like TVs, cars and washing machines. The materials in these products might not be so benign in their environmental impacts, but they would be more tightly constrained in terms of disposal. Typically, they would be leased to the customer. At the end of their useful product life, they would be returned to the producer, where they would be dismantled and recycled back into production in some way. Producers would be responsible for this recycling, and so they would have great incentive to design their products for disassembly.