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National Drinking Water Database - Chemical Contaminants

2,4,5-TP (Silvex)

Status: Regulated - EPA has established a maximum legal limit in tapwater for this contaminant.

2,4,5-TP (Silvex) is an herbicide banned in 1985; it was formerly used in homes and on recreation areas, industrial sites, lumber yards, vacant lots, lawns and turf, and crops including rice. [read more]

2,4,5-TP (Silvex) 2,4,5-TP [2-(2,4,5-trichlorophenoxy)propionic acid], or Silvex, is a chlorophenoxy herbicide that was banned in 1985 because of its toxicity and potential carcinogenicity. Silvex can also be contaminated with dioxin, among the most toxic man-made chemicals known (National Toxicology Program (NTP) 2002a). Even though silvex was banned, residues of the herbicide can still contaminate drinking water due to leaching from landfills (California Environmental Protection Agency 2003b). Short-term exposure to 2,4,5-TP can cause nervous system effects, weakness, stomach upset and irritation, and liver and kidney damage. Longer-term exposure also causes liver and kidney damage. 2,4,5-TP prevents formation of ATP, the primary form of energy used in living organisms, by liver mitochondria (Zychlinski and Zolnierowicz 1990). Silvex has a maximum contaminant level (MCL) in drinking water of 0.05 parts per million (ppm) (U.S. Environmental Protection Agency (USEPA) 2004b).

	Detected	Found above health guidelines	Found above legal limit
States	10	1	-
Water utilities	20	1	-
People Served	3,218,735	50	-

Health Concerns for 2,4,5-TP (Silvex):

• Occupational hazards
• Irritation (skin, eyes, or lungs)
• Organ system toxicity (non-reproductive)
• Cancer
• Ecotoxicology

2,4,5-TP (Silvex) Exposure by State

Water utilities in 10 states have reported detecting 2,4,5-TP (Silvex) in treated tap water since 2004, according to EWG's analysis of water quality data supplied by state water agencies.

State	Water Suppliers with 2,4,5-TP (Silvex) contamination		Water suppliers reporting 2,4,5-TP (Silvex) above health-based limits
	Systems	Population	Systems	Population
Florida	8	2,629,910	1	50
Indiana	1	250,000	0	0
Delaware	1	201,000	0	0
Connecticut	3	39,897	0	0
Virginia	1	37,000	0	0
Maryland	2	32,194	0	0
Wisconsin	1	14,000	0	0
South Dakota	1	13,703	0	0
New York	1	800	0	0
North Carolina	1	231	0	0
Total	20	3,218,735	1	50

The Most Polluted Communities

20 water utilities reported detecting 2,4,5-TP (Silvex) in tap water since 2004, according to EWG's analysis of water quality data supplied by state water agencies

Ranked by highest average 2,4,5-TP (Silvex) level

Rank	System	Population Served	Positive test results of total reported tests	Average Level (Range)
1	Glen St. Mary Water System Glen St. Mary, FL	50	1 of 10	2.8 ppb (0 to 28 ppb)
2	Yankton Yankton, SD	13,703	1 of 2	1.05 ppb (0 to 2.1 ppb)
3	City of Manassas Manassas, VA	37,000	1 of 2	0.7 ppb (0 to 1.4 ppb)
4	Florida City Florida City, FL	9,445	1 of 3	0.33 ppb (0 to 1 ppb)
5	CTWC - Naugatuck Reg-Collinsville Sys Naugatuck, CT	6,324	1 of 5	0.09 ppb (0 to 0.44 ppb)
6	Paradise Point S/D Gastonia, NC	231	1 of 7	0.08 ppb (0 to 0.56 ppb)
7	Whitewater Waterworks Whitewater, WI	14,000	1 of 1	0.05 ppb (0.05 ppb)
8	Town of Federalsburg Federalsburg, MD	2,450	1 of 1	0.03 ppb (0.03 ppb)
9	Putnam Water Pollution Control Authority Putnam, CT	7,300	1 of 11	0.02 ppb (0 to 0.22 ppb)
10	New London Dept. of Public Utilities New London, CT	26,273	1 of 6	0.02 ppb (0 to 0.12 ppb)

Health Based Limits for 2,4,5-TP (Silvex)

Standard	Description	Level
EPA Human Health Water Quality Criteria	Water quality criteria set by the US EPA provide guidance for states and tribes authorized to establish water quality standards under the Clean Water Act (CWA) to protect human health. These are non-enforceable standards based upon exposure by both drinking water and the contribution of water contamination to other consumed foods. Source: U.S. Environmental Protection Agency.	10 ppb
California Public Health Goals	Defined by the State of California Office of Environmental Health Hazard Assessment (OEHHA) as the level of contaminant that is allowed in drinking water. For acutely toxic substances, levels are set at which scientific evidence indicates that no known or anticipated adverse effects on health will occur, plus an adequate margin-of safety. PHGs for carcinogens or other substances which can cause chronic disease shall be based solely on health effects without regard to cost impacts and shall be set at levels which OEHHA has determined do not pose any significant risk to health.	25 ppb
Maximum Contaminant Limit (MCL)	The enforceable standard which defines the highest level of a contaminant that is allowed in drinking water. MCLs are set as close to health-based limits (Maximum Contaminant Level Goals, or MCLGs) as feasible using the best available analytical and treatment technologies and taking cost into consideration. Source: U.S. Environmental Protection Agency.	50 ppb
Maximum Contaminant Limit Goal (MCLG)	A non-enforceable health goal that is set at a level at which no known or anticipated adverse effect on the health of persons occurs and which allows an adequate margin of safety. Source: U.S. Environmental Protection Agency.	50 ppb
Lifetime health-based limit, non-cancer risk	Concentration of a chemical in drinking water that is not expected to cause any adverse, noncarcinogenic health effects for a lifetime of exposure. The Lifetime health-based limit (or Health Advisory, HA) is based on exposure for a a 70-kg adult consuming 2 liters of water per day. Source: U.S. Environmental Protection Agency.	50 ppb
Children's health-based limit for 1-day exposure	Concentration of a chemical in drinking water that is not expected to cause any adverse, noncarcinogenic health effects for up to one day of exposure. The One-Day health-based limit (or Health Advisory, HA) is typically set to protect a 10-kg child consuming 1 liter of water per day. Source: U.S. Environmental Protection Agency.	200 ppb
Children's health-based limit for 10-day exposure	Concentration of a chemical in drinking water that is not expected to cause any adverse, noncarcinogenic effects for up to ten days of exposure. The Ten-Day health-based limit (or Health Advisory, HA) is typically set to protect a 10-kg child consuming 1 liter of water per day. Source: U.S. Environmental Protection Agency.	200 ppb
Drinking Water Equivalent Level	A lifetime exposure concentration protective of adverse, noncarcinogenic health effects, that assumes all of the exposure to a contaminant is from drinking water. Source: U.S. Environmental Protection Agency.	300 ppb

Testing Summary for 2,4,5-TP (Silvex)

Are tests routinely required for 2,4,5-TP (Silvex) by federal law?	Yes
Water suppliers reporting tests for 2,4,5-TP (Silvex) (2004-2009):	19,454 of 47,576
Average testing rate for water supplier reporting tests (2004-2009):	0.4 per year

Violation Summary for 2,4,5-TP (Silvex)

Data from the U.S. Environmental Protection Agency includes the following violations of federal standards for 2,4,5-TP (Silvex) since 2004

Maximum Contaminant Level Exceedance Violations	0
Monitoring Violations	1,676
Reporting Violations	0

Occupational hazards

Type of concern:	Reference:
Allowed workplace exposures restricted to low doses	European Union - Classification & Labelling

Irritation (skin, eyes, or lungs)

Type of concern:	Reference:
Classified as irritant	European Union - Classification & Labelling

Organ system toxicity (non-reproductive)

Type of concern:	Reference:
Classified as toxic or harmful	European Union - Classification & Labelling

Cancer

Type of concern:	Reference:
Cancer - not classifiable/not likely to be human carcinogen	EPA Integrated Risk Information System (IRIS)

Ecotoxicology

Type of concern:	Reference:
Wildlife and environmental toxicity	European Union - Classification & Labelling

Government, industry, academic studies and classifications

government/industry list/academic study	appears on list as	classification(s)
European Union - Classification & Labelling	FENOPROP	•Harmful •Harmful if swallowed •Irritant (eyes, skin, or lungs) •Irritating to skin •Dangerous for the environment •Very toxic to aquatic organisms
EPA Integrated Risk Information System (IRIS)	2(2,4,5-TRICHLOROPHENOXY) PROPIONIC ACID (2,4,5-TP)	•Group D: Not classifiable as to human carcinogenicity (EPA classification)

references

government/industry list/academic study	reference
European Union - Classification & Labelling	CPS&Q (Consumer Products Safety & Quality) formely known as ECB (European Chemicals Bureau). 2008. Classification and Labelling: Chemicals: Annex VI of Directive 67/548/EEC through the 31st ATP.
EPA Integrated Risk Information System (IRIS)	EPA (U.S. Environmental Protection Agency). 2008. Integrated Risk Information System (IRIS). Evidence for human carcinogenicity based on 1986-2005 guidelines.

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