Where It Comes From
Legacy use on rangeland, rights‑of‑way, and lawns; residues at manufacturing or disposal sites; it can get into surface and groundwater. EPA’s drinking water limit (MCL) is 0.05 mg/L [2].
How You Are Exposed
Drinking contaminated private well or small system water; contact with contaminated soil or sediment; work during site cleanup or with old stockpiles [1][2].
Why It Matters
Short-term high exposure can cause irritation and nervous system symptoms; longer-term exposure above guidelines may affect the liver and kidneys. Concern has also centered on possible TCDD (dioxin) impurities, a known human carcinogen [1][2][3].
Who Is at Risk
People using private wells near former application or disposal areas; cleanup workers; pregnant people and young children [1][2].
How to Lower Your Exposure
Test private well water for 2,4,5-TP; if detected, use certified activated carbon or ion-exchange treatment; avoid disturbing contaminated soils; follow PPE and local advisories during cleanup [2][4].
References
- [1]ATSDR. Toxicological Profile for Chlorophenoxy Herbicides (2,4-D; 2,4,5-T). U.S. HHS.
- [2]U.S. EPA. Consumer Factsheet on: 2,4,5-TP (Silvex) and National Primary Drinking Water Regulations.
- [3]IARC. TCDD (dioxin) — Group 1 carcinogen.
- [4]CDC. Choosing Home Water Filters & Other Water Treatment Systems.