endothall

Endothall is a synthetic small molecule herbicide primarily used for the control of aquatic and terrestrial weeds. Chemically known as 7‑oxabicyclo[2.2.1]heptane‑2,3‑dicarboxylic acid (C8H10O5), it acts as a contact herbicide that inhibits plant protein phosphatases—specifically protein phosphatase 1 (PP1) and protein phosphatase 2A (PP2A)—disrupting essential cellular processes such as respiration and synthesis of proteins and lipids in plants[4][5]. It is available in several formulations including dipotassium salt (e.g., Aquathol) and monoamine salts (e.g., Hydrothol 191), with each formulation varying in efficacy against different plant species and toxicity to aquatic organisms[4][6]. Endothall degrades rapidly by microbial action in water environments within about one to two months[6][8]. It is not considered neurotoxic or mutagenic nor likely to be carcinogenic to humans at environmental exposure levels; however acute overexposure can cause depressed breathing or heart rate while chronic exposure may affect organ weights of the stomach or intestine[1][7].

Brand names

AquatholHydrothol 191Hydrothol191Hydrothol-191Hydrothal47Hydrothal-47Hydrothal 47TriEndothal

Other names

DesicateHydrothal191Hydrothal-191Hydrothal 191Hydrothal47Hydrothal-47Hydrothal 47TriEndothal(+/-)-endothallPhthalic acid, hexahydro3,6endooxy1,2-dicarboxy–3,6-endoxocyclohexane3,6-Epoxycyclohexane–1,2-dicarboxylic acid