Tribufos

Synonyms

B 1776; B-1,776; Butifos; Butiphos; Butyl phosphorotrithioate; Butyl phosphorotrithioate ((BuS)3PO); Chemagro B-1776; DEF; DEF defoliant; De-Green; E-Z-Off D; Fos-Fall A; Fossfall; Ortho phosphate defoliant; S,S,S-Tributyl phosphorotrithioate; S,S,S-Tributyl trithiophosphate; S,S,S-Tributyltrithiofosfat [Czech]; TBTP; Tribuphos; [ChemIDplus]

Category

Organophosphate Insecticides

Description

Colorless to pale yellow liquid; [Merck Index]

Sources/Uses

Used as cotton defoliant (for machine harvesting), synergist for insecticides, insecticide, herbicide, and growth regulator; [HSDB] Used in the US strictly for defoliating cotton prior to machine harvesting; General use pesticide; [Reference #1]

Comments

Delayed neuropathy has been reported in at least one agricultural worker; Causes moderate skin and minimal eye irritation in rabbits; Anemia observed in females during one year feeding at nominal doses (NOEL for anemia in females = 0.4 mg/kg); Effects in two year feeding study with rats include bilateral retinal and optic nerve atrophy, cataract, corneal opacity, and signs of anemia, but no adverse effects observed for oncogenicity or neurotoxicity; Reproductive toxicity observed at doses maternally toxic; No evidence of teratogenicity in two animal studies; Evidence for delayed neurotoxicity in hens exposed to single dermal dose of 250-1000 mg/kg; No evidence of mutagenicity; [HSDB] “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]

Reference Link #1

Biomedical References

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]

5.3E-06 mm Hg

LCLo (mice) = 3,804 mg/m3/1h

Predominantly motor

Other Poison

Organophosphate

Diseases

Occupational diseases associated with exposure to this agent:

• Organophosphates & carbamates, acute poisoning

Processes

Industrial Processes with risk of exposure:

• Farming (Pesticides)