Contaminant Candidate List 3 (CCL 3)
In February 2008 we announced the draft CCL 3 and our efforts to expand and strengthen the CCL listing process to identify unregulated contaminants that may require a national drinking water regulation in the future. We will accept public comment on the draft list for 90 days following publication in the Federal Register.
- On this page
- Overview of CCL 3 Process
- CCL 3 List
- CCL 3 Technical Support Documents
- General Information Websites on Contaminants
Other resources
- Federal Register Notice:
- Drinking Water Contaminant Candidate List 3--Draft | PDF Version (28pp, 271K, About PDF)
- Fact Sheet PDF (7pp 54K, About PDF)
EPA 815-F-08-001 - Related Activities and Dates
Overview of CCL 3 Process
In developing the draft CCL 3, we implemented a different process from that used for CCL 1 and CCL 2. This new process builds on evaluations used for previous CCLs and was based on substantial expert input and recommendations from the National Academy of Science’s National Research Council (NRC) and the National Drinking Water Advisory Council (NDWAC).
We used a multi-step CCL process to identify contaminants for inclusion on the draft CCL 3. The key steps include:
- Identifying a broad universe of potential drinking water contaminants (called the CCL 3 Universe). We initially considered approximately 7,500 potential chemical and microbial contaminants.
- Applying screening criteria to the universe we identified 560 of those contaminants that should be further evaluated (the preliminary CCL or PCCL) based on a contaminant’s potential to occur in public water systems and the potential for public health concern.
- We then selected 104 contaminants from the PCCL to include on the CCL based on more detailed evaluation of occurrence and health effects and expert judgment applied in a transparent reproducible manner.
- We incorporated information from the public, expert input, and expert review in the CCL process.
CCL 3 Candidates
Microbial Contaminant Candidates
Microbial Contaminant Name | Information |
---|---|
Caliciviruses | Virus (includes Norovirus) causing mild self-limiting gastrointestinal illness |
Campylobacter jejuni | Bacterium causing mild self-limiting gastroentestinal illness |
Entamoeba histolytica | Protozoan parasite which can cause short as well as long-lasting gastrointestinal illness |
Escherichia coli (0157) | Toxin-producing bacterium causing gastrointestinal illness and kidney failure |
Helicobacter pylori | Bacterium sometimes found in the environment capable of colonizing human gut that can cause ulcers and cancer |
Hepatitis A virus | Virus that causes a liver disease and jaundice |
Legionella pneumophila | Bacterium found in the environment including hot water systems causing lung diseases when inhaled |
Naegleria fowleri | Protozoan parasite found in shallow, warm surface and ground water causing primary amebic meningoencephalitis |
Salmonella enterica | Bacterium causing mild self-limiting gastrointestinal illness |
Shigella sonnei | Bacterium causing mild self-limiting gastrointestinal illness and bloody diarrhea |
Vibrio cholerae | Bacterium found in the environment causing gastrointestinal illness |
Chemical Contaminant Candidates
Contaminant | CASRN | Information about the contaminant |
---|---|---|
alpha-Hexachlorocyclohexane | 319-84-6 | It is a component of benzene hexachloride (BHC) and was formerly used as an insecticide. |
1,1,1,2-Tetrachloroethane | 630-20-6 | It is an industrial chemical used in the production of other substances. |
1,1-Dichloroethane | 75-34-3 | It is an industrial chemical used as a solvent. |
1,2,3-Trichloropropane | 96-18-4 | It is an industrial chemical used in paint manufacture. |
1,3-Butadiene | 106-99-0 | It is an industrial chemical used in rubber production. |
1,3-Dinitrobenzene | 99-65-0 | It is an industrial chemical and is used in the production of other substances. |
1,4-Dioxane | 123-91-1 | It is used as a solvent or solvent stabilizer in the manufacture and processing of paper, cotton, textile products, automotive coolant, cosmetics and shampoos. |
1-Butanol | 71-36-3 | It is used in the production of other substances, and as a paint solvent and food additive. |
2-Methoxyethanol | 109-86-4 | It is used in consumer products, such as synthetic cosmetics, perfumes, fragrances, hair preparations, and skin lotions. |
2-Propen-1-ol | 107-18-6 | It is used in the production of other substances, and in the manufacture of flavorings and perfumes. |
3-Hydroxycarbofuran | 16655-82-6 | It is a carbamate, and is a pesticide degradate. The parent, carbofuran, is used as an insecticide. |
4,4'-Methylenedianiline | 101-77-9 | It is used in the production of other substances, and as a corrosion inhibitor and curing agent for polyurethanes. |
Acephate | 30560-19-1 | It is used as an insecticide. |
Acetaldehyde | 75-07-0 | It is used in the production of other substances, and as a pesticide and food additive. |
Acetamide | 60-35-5 | It is used as a solvent, solubilizer, plasticizer, and stabilizer. |
Acetochlor | 34256-82-1 | It is used as an herbicide for weed control on agricultural crops. |
Acetochlor ethanesulfonic acid (ESA) | 187022-11-3 | Acetochlor ESA is an acetanilide pesticide degradate. The parent, acetochlor, is used as an herbicide for weed control on agricultural crops. |
Acetochlor oxanilic acid (OA) | 184992-44-4 | Acetochlor OA is an acetanilide pesticide degradate. The parent, acetochlor, is used as an herbicide for weed control on agricultural crops. |
Acrolein | 107-02-8 | It is used as an aquatic herbicide, rodenticide, and industrial chemical. |
Alachlor ethanesulfonic acid (ESA) | 142363-53-9 | Alachlor ESA is an acetanilide pesticide degradate. The parent, alachlor, is used as an herbicide for weed control on agricultural crops. |
Alachlor oxanilic acid (OA) | 171262-17-2 | Alachlor OA is an acetanilide pesticide degradate. The parent, alachlor, is used as an herbicide for weed control on agricultural crops. |
Aniline | 62-53-3 | It is used as an industrial chemical, as a solvent, in the synthesis of explosives, rubber products, and in isocyanates. |
Bensulide | 741-58-2 | It is used as an herbicide. |
Benzyl chloride | 100-44-7 | It is used in the production of other substances, such as plastics, dyes, lubricants, gasoline and pharmaceuticals. |
Butylated hydroxyanisole | 25013-16-5 | It is used as a food additive (antioxidant). |
Captan | 133-06-2 | It is used as a fungicide. |
Chloromethane (Methyl chloride) | 74-87-3 | It is used as a foaming agent and in the production of other substances. |
Clethodim | 110429-62-4 | It is used as an herbicide. |
Cobalt | 7440-48-4 | It is a naturally-occurring element and was formerly used as cobaltus chloride in medicines and as a germicide. |
Cumene hydroperoxide | 80-15-9 | It is used as an industrial chemical and is used in the production of other substances. |
Cyanotoxins (3)* | Toxins naturally produced and released by cyanobacteria ("blue-green algae"). Various studies suggest three cyanotoxins for consideration: Anatoxin-a, Microcystin-LR, and Cylindrospermopsin. | |
Dicrotophos | 141-66-2 | It is used as an insecticide. |
Dimethipin | 55290-64-7 | It is used as an herbicide and plant growth regulator. |
Dimethoate | 60-51-5 | It is used as an insecticide on field crops, (such as cotton), orchard crops, vegetable crops, in forestry and for residential purposes. |
Disulfoton | 298-04-4 | It is used as an insecticide. |
Diuron | 330-54-1 | It is used as an herbicide. |
Ethion | 563-12-2 | It is used as an insecticide. |
Ethoprop | 13194-48-4 | It is used as an insecticide. |
Ethylene glycol | 107-21-1 | It is used as an antifreeze, in textile manufacture and is a cancelled pesticide. |
Ethylene oxide | 75-21-8 | It is used as a fungicidal and insecticidal fumigant. |
Ethylene thiourea | 96-45-7 | It is used in the production of other substances, such as for vulcanizing polychloroprene (neoprene) and polyacrylate rubbers, and as a pesticide. |
Fenamiphos | 22224-92-6 | It is used as an insecticide. |
Formaldehyde | 50-00-0 | It has been used as a fungicide, may be a disinfection byproduct, and can occur naturally. |
Germanium | 7440-56-4 | It is a naturally-occurring element and is commonly used as germanium dioxide in phosphors, transistors and diodes, and in electroplating. |
HCFC-22 | 75-45-6 | It is used as a refrigerant, as a low-temperature solvent, and in fluorocarbon resins, especially in tetrafluoroethylene polymers. |
Hexane | 110-54-3 | It is used as a solvent and is a naturally-occurring alkane. |
Hydrazine | 302-01-2 | It is used in the production of other substances, such as rocket propellants, and as an oxygen and chlorine scavenging compound. |
Methamidophos | 10265-92-6 | It is used as an insecticide. |
Methanol | 67-56-1 | It is used as an industrial solvent, a gasoline additive and also as anti-freeze. |
Methyl bromide (Bromomethane) | 74-83-9 | It has been used as a fumigant as a fungicide. |
Methyl tert-butyl ether | 1634-04-4 | It is used as an octane booster in gasoline, in the manufacture of isobutene and as an extraction solvent. |
Metolachlor | 51218-45-2 | It is used as an herbicide for weed control on agricultural crops. |
Metolachlor ethanesulfonic acid (ESA) | 171118-09-5 | Metolachlor ESA is an acetanilide pesticide degradate. The parent, metolachlor, is used as an herbicide for weed control on agricultural crops. |
Metolachlor oxanilic acid (OA) | 152019-73-3 | Metolachlor OA is an acetanilide pesticide degradate. The parent, metolachlor, is used as an herbicide for weed control on agricultural crops. |
Molinate | 2212-67-1 | It is used as an herbicide. |
Molybdenum | 7439-98-7 | It is a naturally-occurring element and is commonly used as molybdenum trioxide as a chemical reagent. |
Nitrobenzene | 98-95-3 | It is used in the production of aniline, and also as a solvent in the manufacture of paints, shoe polishes, floor polishes, metal polishes, explosives, dyes, pesticides and drugs (such as acetaminophen), and in its re-distilled form (oil of mirbane) as an inexpensive perfume for soaps. |
Nitrofen | 1836-75-5 | It is used as an herbicide. |
Nitroglycerin | 55-63-0 | It is used in pharmaceuticals, in the production of explosives, and in rocket propellants. |
N-Methyl-2-pyrrolidone | 872-50-4 | It is a solvent in the chemical industry, and is used for pesticide application and in food packaging materials. |
N-nitrosodiethylamine (NDEA) | 55-18-5 | It is a nitrosamine used as an additive in gasoline and in lubricants, as an antioxidant, as a stabilizer in plastics, and also may be a disinfection byproduct. |
N-nitrosodimethylamine (NDMA) | 62-75-9 | It is a nitrosamine and has been formerly used in the production of rocket fuels, is used as an industrial solvent and an anti-oxidant, and also may be a disinfection byproduct. |
N-nitroso-di-n-propylamine (NDPA) | 621-64-7 | It is a nitrosamine and may be a disinfection byproduct. |
N-Nitrosodiphenylamine | 86-30-6 | It is a nitrosamine chemical reagent that is used as a rubber and polymer additive and may be a disinfection byproduct. |
N-nitrosopyrrolidine (NPYR) | 930-55-2 | It is a nitrosamine used as a research chemical and may be a disinfection byproduct. |
n-Propylbenzene | 103-65-1 | It is used in the manufacture of methylstyrene, in textile dyeing, and as a printing solvent, and is a constituent of asphalt and naptha. |
o-Toluidine | 95-53-4 | It is used in the production of other substances, such as dyes, rubber, pharmaceuticals and pesticides. |
Oxirane, methyl- | 75-56-9 | It is an industrial chemical used in the production of other substances. |
Oxydemeton-methyl | 301-12-2 | It is used as an insecticide. |
Oxyfluorfen | 42874-03-3 | It is used as an herbicide. |
Perchlorate | 14797-73-0 | It is both a naturally occurring and man-made chemical. Most of the perchlorate manufactured in the United States is used as the primary ingredient of solid rocket propellant. |
Permethrin | 52645-53-1 | It is used as an insecticide. |
PFOA (perfluorooctanoic acid) | 335-67-1 | It is used for its emulsifier and surfactant properties in or as fluoropolymers (such as Teflon), fire-fighting foams, cleaners, cosmetics, greases and lubricants, paints, polishes and adhesives and photographic films. |
Profenofos | 41198-08-7 | It is used as an insecticide and an acaricide. |
Quinoline | 91-22-5 | It is used in the production of other substances, and as a pharmaceutical (anti-malarial) and as a flavoring agent. |
RDX (Hexahydro-1,3,5-trinitro-1,3,5-triazine) | 121-82-4 | It is used as an explosive. |
sec-Butylbenzene | 135-98-8 | It is used as a solvent for coating compositions, in organic synthesis, as a plasticizer and in surfactants. |
Strontium | 7440-24-6 | It is naturally-occurring element and is used as strontium carbonate in pyrotechnics, in steel production, as a catalyst and as a lead scavenger. |
Tebuconazole | 107534-96-3 | It is used as a fungicide. |
Tebufenozide | 112410-23-8 | It is used as an insecticide. |
Tellurium | 13494-80-9 | It is a naturally-occurring element and is commonly used as sodium tellurite in bacteriology and medicine. |
Terbufos | 13071-79-9 | It is used as an insecticide. |
Terbufos sulfone | 56070-16-7 | Terbufos sulfone is a phosphorodithioate pesticide degradate. The parent, terbufos, is used as an insecticide. |
Thiodicarb | 59669-26-0 | It is used as an insecticide. |
Thiophanate-methyl | 23564-05-8 | It is used as a fungicide. |
Toluene diisocyanate | 26471-62-5 | It is used in the manufacture of plastics. |
Tribufos | 78-48-8 | It is used as an insecticide and as a cotton defoliant. |
Triethylamine | 121-44-8 | It is used in the production of other substances, and as a stabilizer in herbicides and pesticides, in consumer products, in food additives, in photographic chemicals and in carpet cleaners. |
Triphenyltin hydroxide (TPTH) | 76-87-9 | It is used as a pesticide. |
Urethane | 51-79-6 | It is used as a paint ingredient. |
Vanadium | 7440-62-2 | It is a naturally-occurring element and is commonly used as vanadium pentoxide in the production of other substances and as a catalyst. |
Vinclozolin | 50471-44-8 | It is used as a fungicide. |
Ziram | 137-30-4 | It is used as a fungicide. |
CCL 3 Technical Support Documents
CCL 3 Microbial Documents
- Identifying the Universe PDF (41p 137K, About PDF)
EPA 815-R-08-005 - Screening to the PCCL PDF (102pp 273K, About PDF)
EPA 815-R-08-006 - PCCL to CCL Process PDF (53pp 302K, About PDF)
EPA 815-R-08-007
CCL 3 Chemical Documents
- Identifying the Universe PDF (236pp 2M, About PDF)
EPA 815-R-08-002 - Screening to a PCCL PDF (41pp 379K, About PDF)
EPA 815-R-08-003 - Classification of the PCCL to the CCL PDF (70pp 387K, About PDF)
EPA 815-R-08-004
For additional CCL 3 support documents and more detailed information on the contaminants, visit docket number EPA-HQ-OW-2007-1189 at Regulations.gov.
General Information Websites
The list of websites below provides resources for general information on chemical contaminants.
- Pesticide Reregistration Status
This EPA Office of Pesticide Programs provides fact sheets for pesticides in PDF form. Fact sheets include information in narrative and table form on use; health; risk (dietary, occupational, residential & ecological); and risk mitigation. Data elements include NOAEL, LOAEL, RfD, EEC, LD50, LC50 values, and critical effects for each of these. Also available are production, use and exposure assessment data. - Integrated Risk Information System (IRIS)
This EPA site presents information from chronic health hazard assessments for non-carcinogenic effects and carcinogenicity assessments for lifetime exposure. Data elements for non-cancer data include RfD and RfC values, and specify critical organs and effects, type of study, animal model used, year of study, duration of study, and so on. Data elements for cancer data include oral slope factor values, drinking water unit risk values, dose-response relationships, and cancer class. - Substance Registry System (SRS)
This EPA site provides information on substances and how they are represented in the EPA regulations and information systems. The SRS is EPA’s central system for information about regulated and monitored substances. The system provides a common basis for identification of chemicals, biological organisms, and other substances listed in EPA regulations and data systems, as well as substances of interest from other sources, such as publications. You can query for substances by common identifiers, names, or alternate identifiers. - ChemIDplus Advanced
This U.S. National Library of Medicine source provides chemical structure; chemical classification (type of chemical or use); registry number; synonyms & names; toxicity information (such as LD50 and LC50) drawn from primary literature. - ATSDR Toxicity Profiles
This U.S. Agency for Toxic Substances and Disease Registry (ATSDR) source lists toxicological profiles in PDF form for various chemicals under "Finalized Toxicological Profiles." These profiles include health effects; chemical & physical properties; production, import/export, use and disposal information; potential for human exposure; analytical methods; and regulations & advisories for a given chemical. - Hazardous Substances Data Bank (HSDB)
This U.S. National Library of Medicine (USNLM) source includes information on human health effects; emergency medical treatment; animal toxicity studies; metabolism/pharmacokinetics; environmental fate & exposure; environmental standards and regulations; chemical/physical properties; chemical safety & handling; manufacturing/use information; analytical laboratory methods; and synonyms & identifiers for a given chemical.