Maximum Contaminant Level:  0.2 ppm (200 ppb)

Maximum Contaminant Level Guideline:  0.2 ppm (200 ppb)

Major Use: control of insects, mites and nematodes on field crops, fruits and ornamentals with the majority on apples, potatoes and tomatoes

Other Uses:

Trade Names: Vydate K, Thioxamyl, Dioxamyl, DPX 1410, Dupont 1410

Potential Health Effects: Short-term: tremors, salivation and tearing due to interference with nerve function. Long-term: decreased body weight

Maximum Contaminant Level:  0.001 ppm (1 ppb)

Maximum Contaminant Level Guideline:  zero

Major Use: a wood preservative (fungicide)

Other Uses: banned in 1987 as an over the counter product and for other uses as an herbicide

Trade Names: PCP,Pentachlorol, Dowicide 7, Permasan, Fungifen, Grundier arbezol, Lauxtol, Liroprem, Chlon, Dura Treet II, Santophen 20, Woodtreat, Penta Ready, Penta WR, Forpen-50, Ontrack WE Herbicide, Ortho Triox, Osmose WPC, Watershed WP, Weed and Brush Killer H

Potential Health Effects: Short-term: damage to the central nervous system. Long-term: reproductive effects and damage to liver and kidneys; cancer.

Maximum Contaminant Level:  0.5 ppm (500 ppb)

Maximum Contaminant Level Guideline:  0.5 ppm (500 ppb)

Major Use: in salt form to control annual weeds on crops; with 2,4-D or 2,4,5-T against perennials on non-croplands for bush control

Other Uses: used to control bitterweed, knapweed, leafy spurge, lockweed, larkspur, mesquite, prickly pear and snakeweed on rangelands in western states

Trade Names: “Agent White”, Tordon

Potential Health Effects: Short-term: damage to the central nervous system, weakness, diarrhea, weight loss. Long-term: liver damage

Maximum Contaminant Level:  0.0005 ppm (0.5 ppb)

Maximum Contaminant Level Guideline:  zero

Major Use: no longer used in the U.S.

Other Uses: formerly used as hydraulic fluids, plasticizers, adhesives, fire retardants and way extenders; in inks, lubricants, cutting oils, heat transfer systems and carbonless reproducing paper

Trade Names: PCB, Chlorinated diphenyl, Clophen, Kanechlor, Aroclor, Fenclor, Chlorextol, Dykanol, Inerteen, Monter, Pyralene, Santotherm, Sovol, Therminol, Noflamol

Potential Health Effects: Short-term: acne-like eruptions and pigmentation of the skin; hearing and vision problems; spasms. Long-term: effects similar to acute poisonings; irritation of nose, throat and gastrointestinal tracts; changes in liver function; cancer.

Maximum Contaminant Level:  0.0005 ppm (0.5 ppb)

Maximum Contaminant Level Guideline:  zero

Major Use: making other organic chemicals

Other Uses: making lead free gasoline, paper coating, soil fumigant for nematodes and insecticide for stores grain

Trade Names: Nematox, Vidden D, Dowfume EB-5

Potential Health Effects: Short-term: damage to liver, kidneys, adrenal glands, bladder, and gastrointestinal and respiratory tracts. Long-term: liver, kidneys, bladder, gastrointestinal and respiratory tract; cancer

Radium 226 and Radium 228 (combined)

Radionuclides are elements that are undergoing a process of natural decay.  As they decay, they emit ionizing radiation in the form of alpha or beta particles and gamma photons.  Radiation can cause various forms of cancer.

Maximum Contaminant Level:  5 picocuries per liter (pCi/L)

Maximum Contaminant Level Guideline:  none

Potential Health Effects: Increased risk of cancer

Sources: Erosion of natural deposits

Selenium- an inorganic nonmetallic element that resembles sulfur and tellurium chemically, is obtained chiefly as a by-product in copper refining

Maximum Contaminant Level:  0.05 ppm (50 ppb)

Maximum Contaminant Level Guideline:  0.05 ppm (50 ppb)

Major Use: electronic and photocopier components

Other Uses: glass, pigments, rubber, metal alloys, textiles, petroleum, medical therapeutic agents and photographic emulsion

Potential Health Effects: Short-term: Selenium is an essential nutrient at low levels. However, EPA has found selenium to potentially cause the following health effects when people are exposed to it at levels above the MCL for relatively short periods of time: hair and fingernail changes; damage to the peripheral nervous system; fatigue and irritability. Long-term: Hair and fingernail loss; damage to kidney and liver tissue, and the nervous and circulatory systems. 

Simazine- an organic solid that is white

Maximum Contaminant Level:  0.004 ppm (4 ppb)

Maximum Contaminant Level Guideline:  0.004 ppm (ppb)

Major Use: corn herbicide

Other Uses: herbicide for asparagus, artichokes, berries and broad beans; herbicide for non-crop areas like farm ponds and fish hatcheries; and is commonly mixed with other herbicides like Paraquat, Roundup, Surflan and Dual

Trade Names: Aktinit, Batazina, Bitemol, CAT (Herbicide), CDT, Cekuzina-S, Gelgy 27,692, Gesatop, Herbazin, Herbex, Hungazin, Premazine, Primatol-S, Pricep, Printop, Radocon, Simadex, Tafazine, Zeapur

Potential Health Effects: Short-term: weight loss, changes in blood. Long-term: tremors; damage to testes, kidneys, liver and thyroid; gene mutations; cancer

Styrene- an organic liquid that is oily with an aromatic, almost floral odor

Maximum Contaminant Level:  0.1 ppm (100 ppb)

Maximum Contaminant Level Guideline:  0.1 ppm (100 ppb)

Major Use: was used primarily in the synthetic rubber industry

Other Uses: now used as a building block for polymers in making plastics, resins, coatings and paints

Trade Names: Vinyl benzene, Phenethylene, Cinnamene, Diarex HF 77, Styrolene, Styrol, Styropol

Potential Health Effects: Short-term: nervous system effects such as depression, loss of concentration, weakness, fatigue and nausea. Long-term: liver and nerve tissue damage; cancer.

Tetrachloroethylene or Perchloroethylene (Perc)- an organic liquid that is colorless and nonflammable with a mild, chloroform-like odor

Maximum Contaminant Level:  0.005 ppm (5 ppb)

Maximum Contaminant Level Guideline:  zero

Major Use: textile industry

Other Uses: solvent in dry cleaning, removal of grease from metal

Trade Names: Ethylene tetrachloride, Perchloroethylene, PCE, Ankilostin, Didakene, Fedal-un, Nema, Perclene, Persec, Tetlen, Tetracap, Tetraleno, Tetropil, Antisal 1, Dow-per, Perawin, Perchlor, Percosolv, Perk, Perklone, Tetraguer, Tetralex, Tetravec

Potential Health Effects: Short-term: none known. Long-term: possible liver problems; cancer. 

Thallium- an inorganic metallic element that resembles lead in its physical properties and is poisonous

Maximum Contaminant Level:  0.002 ppm (2 ppb)

Maximum Contaminant Level Guideline:  0.0005 ppm (0.5 ppb)

Major Use: compounds in photoelectric cells

Other Uses: in specialized electronic research equipment and as a pesticide

Potential Health Effects: Short-term: Gastrointestinal irritation; nerve damage. Long-term: Changes in blood chemistry; damage to liver, kidney, intestinal and testicular tissues; hair loss.

Toluene- an organic liquid hydrocarbon that resembles benzene but is less volatile, flammable and toxic with an aromatic odor

Maximum Contaminant Level:  1 ppm (1000 ppb)

Maximum Contaminant Level Guideline:  1 ppm (1000 ppb)

Major Use: to make benzene and urethane

Other Uses: as a solvent and as an anti-knock agent for gasoline

Trade Names: Methylbenzene, Methacide, Phenylmethane, Toluol, Antisal 1A

Potential Health Effects: Short-term: minor nervous system disorders such as fatigue, nausea, weakness, confusion. Long-term: more pronounced nervous disorders such as spasms, tremors, impairment of speech, hearing, vision, memory, coordination; liver and kidney damage.

Total Trihalomethanes- any of various derivatives of methane (as chloroform) that have three halogen atoms per molecule

Maximum Contaminant Level:  0.1 ppm (100 ppb)

Maximum Contaminant Level Guideline:  zero

Major Use: by-product formed during the chlorination of drinking water

Other Uses:

Trade Names: TTHMs

Potential Health Effects: Short-term: liver, kidney and central nervous system problems. Long-term: increased risk of cancer

Toxaphene- an organic solid that is amber and waxy with a piney odor

Maximum Contaminant Level:  0.003 ppm (3 ppb)

Maximum Contaminant Level Guideline:  zero

Major Use: insecticide for special needs, mainly in the southern states

Other Uses: was used but now is restricted as an insecticide for cotton, vegetables, livestock and poultry

Trade Names: Chlorinated camphene, Octachlorocamphene, Camphochlor, Agricide Maggot Killer, Alltex, Crestoxo, Compound 3956, Estonox, Fasco-Terpene, Geniphene, Hercules 3956, M5055, Melipax, Motox, Penphene, Phenacide, Phenatox, Strobane-T, Toxadust, Toxakil, Vertac 9090, Toxon 63, Attac, Anatox, Royal Brand Bean Tox 82, Cotton Tox MP82, Security Tox-Sol-6, Security Tox-MP cotton spray, Security Motox 63 cotton spray, Agro-Chem Brand Torbidan 28, Dr. Roger's TOXENE

Potential Health Effects: Short-term: central nervous system effects including restlessness, hyper-excitability, tremors, spasms or convulsions. Long-term: liver and kidney degeneration; central nervous system effects; possible immune system suppression; cancer. 

2,4,5-TP (Silvex)- a white organic powder with little odor

Maximum Contaminant Level:  0.05 ppm (50 ppb)

Maximum Contaminant Level Guideline:  0.05 ppm (50 ppb)

Major Use: was formerly used as an herbicide primarily for control of woody plants. Banned in 1985

Other Uses:

Trade Names: Weed-B-Gon, Propon, Silvi-Rhap, Sta-fast, Miller Nu Set, Aqua-Vex, Color-Set, Ded-Weed, Fenopeop, Fenormone, Fruitone T, Garlon, Kuran, Kurosal G/SL

Potential Health Effects: Short-term: depression and other nervous system effects, weakness, stomach irritation and minor damage to liver and kidneys. Long-term: minor liver and kidney damage

1,2,4-Trichlorobenzene- a colorless organic liquid with an aromatic odor

Maximum Contaminant Level:  0.07 ppm (70 ppb)

Maximum Contaminant Level Guideline:  0.07 ppm (70 ppb)

Major Use: a dye carrier

Other Uses: to make herbicides and other organic chemicals; as a solvent; in wood preservatives; in abrasives

Trade Names: Hostetex L-PEC, Trichlorobenzol

Potential Health Effects: Short-term: changes in liver,kidneys and adrenal glands. Long-term: increased adrenal gland weights

1,1,1-Trichloroethane or Methyl Chloroform- an organic liquid with a chloroform-like odor

Maximum Contaminant Level:  0.2 ppm (200 ppb)

Maximum Contaminant Level Guideline:  0.2 ppm (200 ppb)

Major Use: solvent for removing grease from machined metal products

Other Uses: textile processing and dyeing and in aerosols

Trade Names: Chloroethene, Methylchloroform, Aerothene TT, Algylen, Alpha-T, Chlorten, Gemalgene, Genklene, Dowclene, Solvent 111, Trichloran, Inhibisol

Potential Health Effects: Short-term: damage to the liver, nervous system and circulatory system. Long-term: liver, nervous system and circulatory system damage.

1,1,2-Trichloroethane- an organic liquid with a chloroform-like odor

Maximum Contaminant Level:  0.005 ppm (5 ppb)

Maximum Contaminant Level Guideline:  0.003 ppm (3 ppb)

Major Use: used to make vinylidene chlorode which is used to make synthetic fibers and plastic wraps such as the Saran wrap

Other Uses: none

Trade Names: Beta trichloroethane, Beta-T, Vinyl trichloride

Potential Health Effects: Short-term: irritation of gastrointestinal tract; red or hemorrhaged lungs; pale liver. Long-term: damage to liver and kidneys; cancer.

Trichloroethylene or TCE- an organic liquid that is colorless or blue with a chloroform-like odor

Maximum Contaminant Level:  0.005 ppm (5 ppb)

Maximum Contaminant Level Guideline:  zero

Major Use: removing grease form fabricated metal parts

Other Uses: removing grease from some textiles; as a solvent and in dry cleaning

Trade Names: 1,1,2-Trichloroethylene, Acetylene trichloroethylene, Algylen, Anameth, Benzinol, Chlorilen, CirCosolv, Germalgene, Lethurin, Perm-a-chlor, Petzinol, Philex,TRI-Plus M, Vitran

Potential Health Effects: Short-term: none known. Long-term: possible liver problems; cancer.

Turbidity- the measure of water clarity

Maximum Contaminant Level:  Treatment Technique: In cases where the EPA has determined it is not technically or economically feasible to establish a Maximum Contaminant Level, they have instead required specific treatment methods to be used to control the level of the contaminant in drinking water.  At no time can turbidity (cloudiness of water) go above 5 nephelolometric turbidity units (NTU); systems that filter must ensure that the turbidity goes no higher than 1 NTU (0.5 NTU for conventional or direct filtration) in at least 95% of the daily samples in any month.

Maximum Contaminant Level Guideline: N/A

Potential Health Effects: Turbidity has no health effects but can interfere with disinfection and provide a medium for microbial growth.  It may indicate the presence of microbes.

Sources: Soil Runoff

Vinyl Chloride- an organic gas that is colorless with a sweet odor

Maximum Contaminant Level:  0.002 ppm (2 ppb)

Maximum Contaminant Level Guideline:  zero

Major Use: depended upon heavily by rubber, paper and glass industries and to make vinyl resins

Other Uses: manufacture of numerous products in building and construction, automotive industry, electrical wire insulation and cables, piping, industrial and household equipment and in medical supplies

Trade Names: Chlorethene, Chlorethylene, Monochloroethene, Monovinyl chloride (MVC), Trovidur

Potential Health Effects: Short-term: damage to the nervous system. Long-term: damage to the liver and nervous system; cancer.

Viruses- an infectious intracellular parasite comprising nucleic acid and a protien coat

Maximum Contaminant Level:  Treatment Technique:In cases where the EPA has determined it is not technically or economically feasible to establish a Maximum Contaminant Level, they have instead required specific treatment methods to be used to control the level of the contaminant in drinking water.

Maximum Contaminant Level Guideline: zero

Potential Health Effects: Gastroenteric Disease

Sources: Human and animal fecal waste

Xylene (Mixed Isomers)- any of three organic hydrocarbons that are toxic, flammable and oily with an aromatic odor

Maximum Contaminant Level:  10 ppm (10,000 ppb)

Maximum Contaminant Level Guideline:  10 ppm (10,000 ppb)

Major Use: obtained from petroleum or natural gas distillates and used as a solvent

Other Uses: in gasoline as part of the BTX (benzene-toluene-xylene) component and to make phthalate plasticizers, polyester fiber, film and fabricated items

Trade Names: Dimethyl benzene Xyol, Violet 3 Methyltoluene

Potential Health Effects: Short-term: disturbance of cognitive abilities, balance and coordination. Long-term: damage to the central nervous system, liver and kidneys.