Residue studies with [¹⁴C] fosamine ammonium in channel catfish

Abstract

The active ingredient in du Pont Krenite brush control agent is ammonium ethyl carbamoylphosphonate (fosamine ammonium salt, formerly known as DPX-1108). Residues in channel catfish exposed to 1.1 ppm 14C-carbonyl-labeled fosamine ammonium in water for 4 wk were found to plateau in 2-3 wk with an accumulation factor (ratio of residue in fish to residue in water) of less than 1. In a separate experiment channel catfish were placed for 4 wk in a tank containing [14C]fosamine ammonium-treated soil (15 ppm) that had been aged for 30 d prior to flooding and initiation of fish exposure. The residue levels in this latter group of catfish also plateaued in 2-3 wk with an accumulation factor of less than 1. In both experiments, after the 4-wk exposures, the fish were transferred to fresh water for 2-wk depuration periods, during which residue levels dropped 50--90%. No effects on the fish were observed during these experiments.

Effects of krenite® brush control agent (fosamine ammonium) on embryonic development in mallards and bobwhite

“…Krenite is relatively nontoxic to mammals (LD50 = 24,000 mg/kg in male rats) [ 2 ] , and no cumulative toxicity or adverse effects in offspring have been noted [3]. Krenite is also relatively nontoxic to mallard ducks (Anus platyrhynchos) and bobwhite quail (Colinus virginianus), with the LD50 being greater than 10,000 mg/kg for both species [4]. However, some recent concern has arisen since Lutz-Ostertag [5] reported that spray application of an unidentified formulation of fosamine ammonium at concentrations of 1 to 5% was highly teratogenic to chicken embryos and Japanese quail (Coturniw japonica) of the "Geromoise" strain when sprayed on the eggs under conditions similar to field application.…”