Coupled with increasing concerns about the environment, the magnitude of federal spending on contracts has prompted numerous questions from Members of Congress and the public about the role of environmental considerations in federal procurement. These include: to what extent do agencies consider environmental factors when procuring goods or services? What legal authorities presently require or allow agencies to take environmental factors into account when acquiring goods or services? How are existing provisions authorizing agencies to consider environmental factors implemented? This report provides an overview, answering these and related questions. It does not address green building initiatives, energy-savings performance contracts, policy documents, agency-specific laws, or environmental laws of general applicability that effectively shape the products available for purchase. Beginning with President Obama's 2009 Executive Order on "Federal Leadership in Environmental, Energy, and Economic Performance," the Obama Administration has taken steps to promote consideration of environmental factors in federal procurement. Recently, for example, the General Services Administration (GSA) reported on plans to incorporate consideration of greenhouse gas emissions inventories into federal procurement decisions, and the Federal Acquisition Regulation was amended to require that contractors report on their purchases of biobased products under service and construction contracts. Certain such initiatives have prompted controversy, however. Some Members of Congress sought to restrict the Department of Defense's purchase of biofuels as part of the National Defense Authorization Act for FY2013, and some commentators have objected to GSA's use of the Leadership in Energy and Environmental Design (LEED) rating system for buildings. Fundamentally, federal procurement involves agencies acquiring the goods and services they need to carry out their missions. The vision for federal acquisition, as presented in the FAR, is "to deliver on a timely basis the best value product or service to the customer, while maintaining the public's trust and fulfilling public policy objectives." Environmental objectives have historically constituted one of the "public policy objectives" to be furthered by federal procurement, and environmental interests were among the "competing interests" in the federal procurement system. However, they were arguably one among many, sometimes competing, policy objectives until the May 2011 amendments to the FAR articulated a "sustainable acquisition policy," which generally requires that agencies shall advance sustainable acquisition by ensuring that 95 percent of new contract actions for the supply of products and for the acquisition of services (including construction) require that the products are— (1) Energy-efficient (ENERGY STAR® or Federal Energy Management Program (FEMP)-designated); (2) Water-efficient; (3) Biobased; (4) Environmentally preferable (e.g., EPEAT-registered, or non-toxic or less toxic alternatives); (5) Non-ozone depleting; or (6) Made with recovered materials. While many of the products to be purchased under this policy (e.g., energy-efficient, biobased) were previously "preferred" in federal procurements, as discussed below, the policy could be said to create increased impetus for their purchase by requiring federal agencies to ensure that 95% of their new "contract actions" entail the acquisition of such products. However, even with the May 2011 amendments to the FAR, agencies would generally not be required to purchase energy-efficient, water-efficient, biobased, environmentally preferable, non-ozone depleting, or recovered-content products in any specific procurement. Rather, they are to ensure that 95% of their new contract actions generally involve such products. It is also important to note that the May amendments generally rely upon, rather than expand, existing legal authorities (discussed below) requiring or permitting agencies to prefer certain products based upon their environmental attributes. In addition, the amendments do not purport to address which "sustainable" product agencies should purchase when two or more different products—each of which agencies purportedly "must" purchase because of its environmental attributes—could meet agency requirements. Moreover, as agencies implement the requirement that 95% of their new contract actions entail the purchase of energy-efficient and similar products, questions could arise about the relationship between the sustainable acquisition policy and other long-standing federal procurement policies. For example, some small businesses that participated in a pilot project to reduce greenhouse gas emissions in the federal supply chain have reported being concerned that they might appear less "environmentally friendly" to contracting officers than competitors that travel shorter distances or can afford more fuel-efficient vehicles. Various legal authorities currently require or allow contracting officers to take environmental considerations into account when procuring goods or services. These authorities can be broadly divided into three categories: (1) "attribute-focused" authorities, generally requiring agencies to avoid or acquire products based on their environmental attributes (e.g., ozone-depleting substances, recovered content); (2) general contracting authorities, allowing agencies to purchase goods with certain environmental attributes when they have bona fide requirements for such goods; and (3) responsibility-related authorities, which require agencies to avoid certain dealings with contractors that have been debarred from government contracting for violations of the Clean Air Act or Clean Water Act. Numerous statutes, regulations, and executive orders enacted or issued since the mid-1970s authorize agencies to "prefer" certain products because of their environmental attributes. This generally means that agencies must purchase products with these attributes instead of competing products that lack them. However, the exact nature of the preference varies by product, as discussed below and illustrated in Table 1 and the Appendix . Because the attribute-focused authorities developed over time and through the actions of different branches of the federal government, they arguably do not represent a holistic framework for or ensure consistency in agencies' treatment of products or vendors on environmental grounds. A number of products are eligible for various preferences in federal procurement, discussed below, because of their environmental attributes. In some cases, the products and their attributes are defined fairly narrowly (e.g., plastic ring carriers, electric motors of 1 to 500 horsepower, solar hot water heaters), although generally not so narrowly as to be identified by brand name. These preferences are typically not incorporated in the FAR, which thus serves as only a partial guide to the products preferred because of their environmental attributes. In other cases, products and attributes are defined more broadly (e.g., biobased products, recovered-content products, etc.). These broader preferences are generally incorporated in Part 23 of the FAR. Many of these preferred products have their own definitions for purposes of federal procurement, as illustrated in the Glossary below. These definitions do not necessarily correspond to everyday or environmentalists' usage of these terms. Moreover, certain attributes which are currently widely discussed in environmental contexts (i.e., "green") are not presently defined for purposes of federal procurement and are not among the attributes in terms of which current preferences are stated. Some commentators have suggested that "green" products could be preferred under the existing authorities pertaining to "environmentally preferable products," which is probably the case in most circumstances. However, it is important to be clear that, absent changes in the law, any preferences given to such products are based on their being "environmentally preferable products," not "green products." The exact nature of the preference(s) given to products based upon their environmental attributes varies by product, but agencies could be required or encouraged to purchase products with the desired environmental attributes instead of competing products that lack these attributes; avoid or minimize purchases of products with certain attributes; draft specifications for goods or services so as to maximize the purchase and use of products with certain environmental attributes; develop "affirmative procurement plans" to maximize the acquisition of products with certain environmental attributes; insert clauses regarding the provision or use of designated products into certain service or construction contracts; use certain environmental considerations as evaluation factors when considering bids or offers; meet goals for the procurement of certain types of products; or report agencies' performance in acquiring preferred products to executive branch authorities, Congress or congressional committees, or the public. In a few cases, agencies are also required to use contract terms that obligate contractors to certify that they have provided designated products, or disclose information about certain environmental impacts of designated products. Table 1 illustrates which preferences generally apply to the major categories of preferred products included in the Glossary. These preferences are seldom absolute, however, not even when agencies are "required" to purchase products with certain attributes. There are several reasons for this. First, the requirements themselves are generally either conditional or subject to exemptions that allow agencies to purchase products without the desired attributes in certain circumstances. Any preferences that agencies give to alternatives to ozone-depleting substances must be "cost-effective," for example, while there are exemptions allowing agencies to purchase products that do not contain biobased content if biobased products cannot be acquired competitively within a reasonable time frame or do not meet reasonable performance standards. Agencies may also exempt certain procurements related to intelligence, law enforcement, or national security activities from the sustainable acquisition requirements under certain circumstances. Second, certain preferences apply only to procurements conducted in particular places, or whose price exceeds certain thresholds. Prior to the May 2011 amendments to the FAR, such preferences generally applied only to contracts for goods and service contracts involving the supply of goods or contractor operation of government-owned facilities. However, both the May 2011 amendments to the FAR and Executive Order 13514 arguably place increased emphasis on environmental considerations in the acquisition of services. Among other things, the May 2011 amendments to the FAR require that [t]he contracting officer shall (1) [s]pecify the [Environmental Management System] EMS directives with which the contractor must comply; and (2) [e]nsure contractor compliance to the same extent as the agency would be required to comply, if the agency operated the facilities and vehicles. While the FAR only requires agencies to incorporate the clause implementing these requirements in contracts for contractor operation of government-owned or -leased facilities or vehicles, certain provisions of Executive Order 13514 have broader applicability.