Substitution patterns.

Coaches of basketball, ice hockey and several other team sports must put some of their strategic thinking into substitution patterns--when to put new players in and when to let the starters return.

Manufacturers and designers of products and packaging alike also have to make the same types of strategic decisions regarding materials.

Scrap metal recyclers can see the results of these decisions on both an immediate and a delayed basis if they handle a mixture of prompt industrial scrap and obsolete scrap.

When a manufacturer shifts from a metallic material to a nonmetallic material, a once steady supply of locally generated scrap metal can disappear.

When a product that was once commonly made of metal, such as residential siding, shifts predominantly to a different material, recyclers of obsolete scrap will notice the difference several years down the road.

The power of the recycling community to either prevent or encourage such substitutions can be limited. Most often, manufacturers are responding to consumer preferences and cost pressures that have little to do with the recycling loop.

But recyclers are not completely powerless and, acting through their trade associations and other joint efforts, touting the closed-loop recyclability of metal can be their winning argument.

One such recent campaign, focusing on aluminum beverage cans, is described in the feature story "Cashing In," found on pages S30-S34 of this supplement.

The term closed-loop recycling may be relatively new within an industry that dates back to the earliest portions of recorded history. But metals producers and the scrap recycling community that serves them may see positive results by constantly reminding the manufacturing community and the wider public that metals are recyclable and sustainable--a couple of very desirable qualities in a resource-hungry world.