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Priority Chemicals
Note: EPA no longer updates this information, but it may be useful as a reference or resource.
The National Waste Minimization Program focuses efforts on reducing 31 Priority Chemicals (PCs) found in our nation's products and wastes by finding ways to eliminate or substantially reduce their use in production. If these chemicals cannot easily be eliminated or reduced at the source, we focus on recovering or recycling them.
These 31 PCs, discussed below, are listed in the following table. A fact sheet including a summary of the potential health effects of each chemical can be accessed by clicking on the chemical name. Next to each chemical name is its Chemical Abstract Services Registry Number (CASRN). 
Some of the documents on this Web page are in PDF format. For information about PDFs, please see the About PDF page.
| Chemical Name & Summary Fact Sheet | CASRN |
|---|---|
| Organic Chemicals and Chemical Compounds | |
| 1,2,4-Trichlorobenzene (PDF) (2 pp, 9K) | 120-82-1 |
| 1,2,4,5-Tetrachlorobenzene (PDF) (2 pp, 9K) | 95-94-3 |
| 2,4,5-Trichlorophenol (PDF) (2 pp, 8K) | 95-95-4 |
| 4-Bromophenyl phenyl ether (PDF) (2 pp, 6xK) | 101-55-3 |
| Acenaphthene (PDF) (2 pp, 11K) | 83-32-9 |
| Acenaphthylene (PDF) (2 pp, 10K) | 208-96-8 |
| Anthracene (PDF) (2 pp, 11K) | 120-12-7 |
| Benzo(g,h,i)perylene (PDF) (2 pp, 11K) | 191-24-2 |
| Dibenzofuran (PDF) (2 pp, 8K) | 132-64-9 |
| Dioxins/Furans (PDF) (2 pp, 10K) (considered one chemical on this list) | 1746-01-6 |
| Endosulfan, alpha (PDF) (2 pp, 11K) & Endosulfan, beta (PDF) (2 pp, 10K) (considered one chemical on this list) | 959-98-8 33213-65-9 |
| Fluorene (PDF) (2 pp, 12K) | 86-73-7 |
| Heptachlor (PDF) (2 pp, 11K) & Heptachlor epoxide (PDF) (2x pp, 11K) (considered one chemical on this list) | 76-44-8 1024-57-3 |
| Hexachlorobenzene (PDF) (2 pp, 10K) | 118-74-1 |
| Hexachlorobutadiene (PDF) (2 pp, 9K) | 87-68-3 |
| Hexachlorocyclohexane, gamma- (PDF) (Lindane) (2 pp, 11K) | 58-89-9 |
| Hexachloroethane (PDF) (2 pp, 10K) | 67-72-1 |
| Methoxychlor (PDF) (2x pp, 10K) | 72-43-5 |
| Naphthalene (PDF) (2 pp, 10K) | 91-20-3 |
| Pendimethalin (PDF) (2 pp, 9K) | 40487-42-1 |
| Pentachlorobenzene (PDF) (2 pp, 9K) | 608-93-5 |
| Pentachloronitrobenzene (PDF) (Quintozene) (2 pp, 9K) | 82-68-8 |
| Pentachlorophenol | 87-86-5 |
| Phenanthrene (PDF) (2 pp, 10K) | 85-01-8 |
| Polycyclic Aromatic Compounds (PACs) / PAH Group (PDF) (2 pp, 12K) (as defined in TRI) | |
| Polychlorinated Biphenyls (PCBs) (PDF) (4 pp, 105K) | 1336-36-3 |
| Pyrene (PDF) (2 pp, 10K) | 129-00-0 |
| Trifluralin (PDF) (2 pp, 9K) | 1582-09-8 |
| Metals and Metal Compunds | |
| Cadmium (PDF) (2 pp, 11K) | 7440-43-9 |
| Lead | 7439-92-1 |
| Mercury | 7439-97-6 |
Twenty-eight organic chemicals are included in the list . The organic chemicals included in the list of Priority Chemicals were selected following an Agency-wide expert review of scientific information available on them. EPA experts reviewed scientific information made available to the public in 1998 and scientific information received from commenters in response to the 1998 Notice of Availability. Based on its review, EPA concluded that 27 organic chemicals are persistent, bioaccumulative, and toxic (PBT). They are currently being generated in industrial waste and are found in soil, sediment, ground water, surface water, air, and plant, animal, and human tissue as a result of past and present releases. Even when released in very small amounts, they accumulate and can cause environmental problems. Many of these organics are difficult to clean up once they get into the environment, resulting in costly clean up efforts. Polychlorinated biphenyls (PCBs) were added in 2004 because of their chemical properties.
Three metals are included in the list. The PC list includes cadmium, lead, and mercury. These metals and their compounds are known to occur frequently in RCRA regulated industrial wastes and often trigger RCRA's Toxicity Characteristic criteria, meaning the wastestreams they are found in must be managed under RCRA hazardous waste regulations. These metals are also a high priority in international waste minimization efforts to which the United States has commitments.
In its 1998 Notice, EPA identified these metals as Priority Chemicals using the same PBT analysis framework that it used for organic chemicals. EPA subsequently decided to defer the use of that framework and is working with its Science Advisory Board to develop a consistent, Agency-wide approach for the evaluation of metals. Nevertheless, EPA believes other information clearly demonstrates that these three metals should be included in the list of 31 Priority Chemicals. EPA's 2001 Biennial Report System (BR) data show that lead is the hazardous constituent found most frequently in RCRA wastestreams. Cadmium is frequently found in wastes containing lead and both of these metals are frequently recoverable. Mercury is also frequently found in hazardous waste and there is a high level of national and international concern over mercury risks.
- Assessing the Management of Lead in Scrap Metal and Electric Arc Furnace Dust (K061 Waste) (PDF) (91 pp, 1.2MB)
In 2004, EPA established a goal of a 10 percent reduction of PCs by 2008, using a 2001 baseline. Although 24 of the 31 PCs are reported to the Toxics Release Inventory (TRI) , only 23 PCs are tracked for the 2008 goal. Polychlorinated Biphenyls (PCBs) are also reported to TRI, but were being tracked separately at the time the 2008 goal was developed. Therefore, PCBs are not tracked for the 2008 goal. As of 2004, there was an overall reduction of approximately 1 million pounds or 2.6 percent in the total quantity of PCs contained in wastes, compared to the quantities generated in 2001. More information on tracking PCs. EPA and International Interest. EPA's Persistent, Bioaccumulative and Toxic (PBT) Program (a cross-Agency environmental program effort) is developing National Action Plans for several of the chemicals included on the Priority Chemical list. These include dioxins/furans, hexachlorobenzene, mercury, benzo(a)pyrene, and six additional polycyclic aromatic hydrocarbons (PAHs). Several PCs are a focus of international efforts. The United States is committed to working with the international community to address chemicals of international concern. EPA is involved in the Canada-United States Binational Toxics Strategy, the United Nations Environment Programme's Persistent Organic Pollutants (POPs) effort, and the United Nations Economic Commission for Europe's Long Range Transport Air Pollutants (LRTAP) Persistent Organic Pollutants effort. Please note that the waste minimization efforts discussed on this website are voluntary. The information contained in this website does not replace EPA's statutes or regulations, nor does information on the website serve as a regulation. Information on this website cannot impose legally binding requirements on EPA, states, or the regulated community. Rather, it acknowledges that EPA is focusing its waste minimization efforts on the 31 PCs identified here. In addition, EPA remains receptive to any waste minimization efforts, including efforts to address chemicals other than, or in addition to, these PCs. We hope the information presented here helps government, the regulated community, and the public to effectively allocate waste minimization resources.