Everyday we make choices about how much waste to produce. As consumers, rarely do we think about how a product was made, to what degree it was used efficiently and where it might end up once it is no longer useful. For example, consider the life cycle of a paper milk carton. To generate the raw material, wood is harvested and made into paper at a mill. Then the paper is labeled and formed and eventually filled with milk. The container is transported to a store and refrigerated, where it can be purchased. Once the milk is consumed, the empty milk container is disposed. At each stage, energy and raw materials are consumed and waste is produced.

The concept of conducting a detailed examination of the life cycle of a product or a process is a relatively recent one which, according to Catherine Wilt from the Center of Clean Products and the University of Tennessee, Life Cycle Assessment (LCA), is becoming more popular given the increased costs to taxpayers and local governments for managing solid waste. According to Wilt, at least 33 countries already have policies and regulations requiring manufacturers to address upstream and downstream environmental and public health impacts associated with their products.

Either on their own or responding to pressures in Europe and elsewhere, a number of entities have already begun the process of looking for more efficient ways to design their products to be more environmentally friendly. For example, California has employed three methods to manage the 100 million gallons of used oil generated in their state each year: re-refining, distillation and combustion as fuel. In 2002, more than 50 million gallons of used oil were marketed as heavy fuel oil without treatment. The majority of this was used overseas with limited pollution controls. The results of an environmental life cycle assessment showed that heavy metal air emissions from used oil fuel far exceeded emissions from other used oil management methods. In fact the net zinc, copper, cadmium and lead emissions were nearly equal to emissions from all of California's large stationary sources combined (based on EPA-TRI). Because of heavy metal emissions, combustion of used oil as fuel may have cause 100 times the environmental impact of used oil re-refining or distillation[1].

According to California's Department of Toxic Substances Control, treatment by re-refining or distillation could result in reduced environmental impact primarily from diversion of used oil as fuel, but also from recycling energy intensive materials back into commerce. This in turn could reduce California's net global environmental impact.

There are a number of other initiatives that are driving life cycle analysis and assessment. Global pressure to improve pollution reduction outcomes from organized management systems, such as ISO 14000, have evolved to the point where some companies are now focusing on the product-oriented portion of the standard, which includes life-cycle assessment, environmental labeling and environmental aspects in product standards. In addition, the American Chemistry Council's Responsible Care" program, led by companies such as DOW Chemical and Ashland Chemical, began a number of years ago implementing product stewardship, pollution prevention and greening of the supply chain activities.

The life cycle trend shows no sign of slowing. Companies such as Panasonic and Dell have reached agreements with Goodwill Industries to recycle computers and electronic gear. A number of carpet manufacturers have teamed up with textile manufacturers for recycling and re-using post-consumer carpet. In addition, wastes from new construction and demolition are being made into new construction materials, while city recycling programs for yard debris and sorted recyclable trash continue to expand - often times being funded with corporately sponsored grant money.

Where is all of this heading? Companies that are suppliers to larger manufacturers, if they have not already, may be hearing more about life cycle analysis. The process normally begins by completing an environmental impact survey. Once the data are assembled, a life cycle assessment is completed. This involves interpretation of the information and making value judgments to determine a product's overall environmental impact. Since all products have some effect on the environment, it can be anticipated that only those which are most harmful will be addressed first. Life cycle changes may include activities such as waste minimization and reduction (including energy), product re-formulation, recycling, pre-cycling, product substitution, etc.

For more information on life cycle analysis and assessment see the following: American Center for life cycle assessment: www.lcacenter.org. The International Journal of Life Cycle Assessment: www.scientificjournals.com/sj/lca/startseite [1]Environmental Science and Technology vol. 38, No2.