CHLORETHOXYFOS

Chemical Properties

Gray to reddish-brown granular solid or colorless liquid. Mild sulfur-like odor.

Chemical Properties

Chlorethoxyfos is a colorless liquid. Technical chlorethoxyfos is a light-to- dark brown liquid. Stable at room temperature for ＞18 months; stable at 55°C for 2 weeks. Chlorethoxyfos is characterized as having a “strong” odor.

Uses

Chlorethoxyfos is a soil-applied organophosphorus insecticide used to control various soil insects (e.g. corn rootworms) in maize.

Uses

Chlorethoxyfos is an organophosphorous pesticide/insecticide.

Uses

Insecticide.

Definition

ChEBI: Chlorethoxyfos is an organic thiophosphate, an organothiophosphate insecticide and an organochlorine insecticide. It has a role as an agrochemical and an EC 3.1.1.7 (acetylcholinesterase) inhibitor.

Agricultural Uses

Insecticide: Chlorethoxyfos is a restricted use organophosphate insecticide registered for use in the U.S. on field corn, seed corn, sweet corn, and popcorn for the control of corn rootworms, wireworms, cutworms, seed corn maggots, white grubs, and symphylans. A U.S. EPA restricted Use Pesticide (RUP). Not listed for use in EU countries.

Trade name

DPX-43898®; FORTRESS 2.5G; FORTRESS® 5G; SD 208304®

Potential Exposure

An organophosphate insecticide, chlorethoxyfos is a restricted use organophosphate insecticide registered for use in the United States on field corn, seed corn, sweet corn, and popcorn for the control of corn rootworms, wireworms, cutworms, seed corn maggots, white grubs, and symphylans. A United States Environmental Protection Agency Restricted Use Pesticide (RUP). Not currently listed for use in EU countries.

Carcinogenicity

According to an EPA summary, an 18 month study in which mice were given diets with chlorethoxyphos (doses not provided) was negative for carcinogenicity . A 2 year rat feeding (doses not provided) study showed a slight, nonsignificant increase in kidney tumors, and EPA concluded “the study was adequate for carcinogenicity testing” but that it was difficult to clearly interpret the data as showing either the presence or the absence of a carcinogenic effect .

Metabolic pathway

Chlorethoxyfos undergoes extensive degradation and metabolism in water, soil, plants and animals. Cleavage of the P-O-tetrachloroethyl bond is the major degradation reaction of chlorethoxyfos. Dechlorination and oxidation of the tetrachloroethyl moiety yielded chloral, dichloroacetic acid and trichloroacetic acid as major degradation products. The extensive metabolism of chlorethoxyfos and its degradation products yielded ¹⁴CO2 and amino acids (glycine, serine, etc.). Oxidative desulfuration to yield chlorethoxyfos-oxon or O-de-ethylation reactions were not observed.

Shipping

UN2783 Organophosphorus pesticides, solid, toxic, Hazard Class: 6.1; Labels: 6.1-Poisonous materials. UN3018 Organophosphorus pesticides, liquid, toxic, Hazard Class: 6.1; Labels: 6.1-Poisonous materials.

Degradation

Chlorethoxyfos is susceptible to alkaline hydrolysis. The DT₅₀ values of chlorethoxyfos in buffers at pH 5, 7 and 9 at 25 °C were 72, 59 and 4.3 days, respectively (Hawhs et al., 1988a). The primary hydrolytic degradation reaction was the cleavage of the P-O-tetrachloroethyl bond. The major [¹⁴C-tetrachloroethyl]chlorethoxyfos degradation product observed in pH 5 and 7 aqueous solutions was chloral (trichloroacetaldehyde, 2), formed probably via the tetrachloroethanol (3) intermediate. In alkaline solution (pH 9), the principal product was dichloroacetic acid (4), formed probably via the dehydrochlorinated intermediate (5).
Chlorethoxyfos degraded slowly in aqueous solution when exposed to UV light at 25 °C [DT₅₀ ca. 27 days (continuous irradiation) vs. 19 days (dark control)] (Hawkins et al., 1988b). Cleavage of the P-O- tetrachloroethoxy bond yielded chloral (2) as the primary aqueous photolysis product.

Incompatibilities

May react violently with antimony(V) pentafluoride. Incompatible with lead diacetate, magnesium, silver nitrate. In the presence of strong reducing agents such as hydrides, organophosphates form highly toxic and flammable phosphine gas. Contact with oxidizers can cause the release of toxic oxides of phosphorus.

Waste Disposal

Destruction by alkali hydrolysis or incineration. May also be mixed with flammable solvent and sprayed into an incinerator equipped with after burner and scrubber. Containers must be disposed of properly by following package label directions or by contacting your local or federal environmental control agency, or by contacting your regional EPA office. Afterburner