Acute toxicity of herbicide formulations and chronic toxicity of technical‐grade trifluralin to larval green frogs (Lithobates clamitans)

Abstract

Fewer toxicity studies have been performed on herbicides than on insecticides despite heavier use of herbicides and evidence of herbicide formulation toxicity to amphibians. We conducted acute and chronic toxicity tests with the herbicide trifluralin (2,6‐dinitro‐N,N‐dipropyl‐4‐(trifluoromethyl)aniline) on tadpoles. Herbicide formulations had lower median lethal concentrations than an insecticide formulation and technical‐grade trifluralin. Chronic trifluralin exposure resulted in significantly smaller tadpoles at low concentrations (20 µg/L) compared with controls and 200‐µg/L treatments. Environ. Toxicol. Chem. 2012; 31: 2029–2034. © 2012 SETAC