Intelligent Product System, or any regulatory system based on the precautionary principle and pollution prevention, require a strong role for the state in banning inappropriate materials. While such bans may sound draconian, they are in fact a long-established practice in all industrial economies. In a green economy, however, the bans are based on ecological intelligence, principles of sustainability, and a longer-range view of human health. And while the state is the ultimate agent of these bans, they can also be implemented by assessment systems, professional associations and the like. As discussed in Chapter I, industrial materials can be categorized into four basic areas: Degradable & Nontoxic, Persistent & Nontoxic, Degradable & Toxic, and Persistent, Bioaccumulative & Toxic (Geiser, 2001). Intelligent policy would have a different strategy for each area, with the overall goal of pushing industry increasingly toward as much production and use of Category 1 (degradable and nontoxic) benign materials as possible. As noted in Chapter III, the ecosystem-like integration of green manufacturing can make possible the production of a great diversity of products from small sets of benign materials. Category 4 materialspersistent, bioaccumulative and toxicshould be phased out as soon as possible because they inevitably create more problems than their use solves. While there are inevitable transition problems, science is rapidly multiplying the possible alternatives, and substitution strategies (discussed in Chapter III) offer a number of options for existing users of toxic substances. As Commoner (1992) has demonstrated, many product bans could quickly pay for themselves several times over because of the pervasive human health and environmental impacts these materials have. Many dangerous substances often entail substantial regulatory to costs to monitor and control their use which could be eliminated entirely