Environmentally-preferable products (EPPs), as defined by the federal government in Executive Order 13101, are those that have alesser or reduced effect on human health and the environment when compared to competing products that serve the same purpose. The growing popularity of green buildings and green building programs (particularly the U.S. Green Building Council’s LEEDr rating sy stem) is expanding both the demand for, and availability of, green products. For designers and spe cifiers, these changes are prov iding greater opportunities to improve the environmental performance of many building products. At the same time, assessing the he alth and environmental impacts of materials is a complex process, which can be further confused by varying (and sometimes contrad