Major Category
Pesticides
Synonyms
(+-)-O-Ethyl S-phenyl ethylphosphonodithioate (8CI)(9CI); Difonate; Difonatul; Doubledown; Dyfonate; Dyfonate Tillam 1-4E; Dyphonate; Ethylphosphonodithioic acid O-ethyl S-phenyl ester; Fonophos; N-2788; N-2790; O-Aethyl-S-phenyl-aethyl-dithiophosphonat [German]; O-Ethyl S-phenyl ethyldithiophosphonate; O-Ethyl S-phenyl ethylphosphonothiolothionate; O-Ethyl-S-phenyl ethylphosphonodithioate; OMS 410; Phosphonodithioic acid, ethyl-, O-ethyl S-phenyl ester; Stauffer N 2790; [ChemIDplus]
Category
Organophosphate Insecticides
Description
Light-yellow liquid with an aromatic odor. [insecticide]; [NIOSH]
Sources/Uses
Used primarily on corn, and also on sugar cane, peanuts, tobacco, turf, and vegetables; [EXTOXNET]
Comments
Classified as "highly toxic," the more concentrated formulations of fonofos may be used only by certified applicators. It persists in soil with a half-life of about 40 days. [EXTOXNET] “The average of two baseline respective cholinesterase activity determinations three days apart, with no exposures to enzyme inhibiting pesticides for at least 30 days, is recommended for each worker prior to exposure to cholinesterase inhibitors because of large inter-individual differences in published baseline values. To be established at least once a year. Removal from workplace exposures is recommended until the cholinesterase activity returns to within 20% of baseline.” [TLVs and BEIs]
BEI
Acetylcholinesterase activity in red blood cells = 70% of individual's baseline; Butylcholinesterase activity in serum or plasma = 60% of individual's baseline; Sample at end of shift; [TLVs and BEIs]
Skin Designation (ACGIH)
Yes
TLV (ACGIH)
0.1 mg/m3, inhalable fraction and vapor
Vapor Pressure
0.0002 mm Hg
Lethal Concentration
LC50 (rat) = 1,900 mg/m31h
ACGIH Carcinogen
Not Classifiable
Other Poison
Organophosphate
Diseases
Occupational diseases associated with exposure to this agent:
Processes
Industrial Processes with risk of exposure: