- O-Ethyl S-phenylethylphosphonodithioate
Light-yellow liquid with a pungent mercaptan-like odor.
Dyfonate is soil insecticide useful in controlling soil insects such as corn rootworms (diabrotica species), wireworms (elateridae), garden symphylan (scutigerella immaculata), root maggots (hylemya species), crickets (gryllidae) & others.
Registry Numbers and Inventories.
EC Index Number
Very toxic; Dangerous for the Environment
Agricultural Chemical and Pesticide; Mutagen
Swiss Giftliste 1
Melting point, °C
Boiling point, °C
Vapor pressure, mmHg
0.0005 (25 C)
1.16 g/cm3 (20 C)
Solubility in water
1.5883 (20 C)
Partition coefficient, pKow
Heat of vaporization
Hazards and Protection.
Stable under normal conditions.
All chemicals should be considered hazardous. Avoid direct physical contact. Use appropriate, approved safety equipment. Untrained individuals should not handle this chemical or its container. Handling should occur in a chemical fume hood.
Wear appropriate protective gloves, clothing and goggles.
Wear positive pressure self-contained breathing apparatus (SCBA).
This compound is a liquid organophosphorus insecticide. Keep unnecessary people away; isolate hazard area and deny entry. Stay upwind; keep out of low areas. Ventilate closed spaces before entering them. Remove and isolate contaminated clothing at the site. Do not touch spilled material; stop leak if you can do so without risk. Use water spray to reduce vapors. Small spills: absorb with sand or other noncombustible absorbent material and place into containers for later disposal. Large spills: dike far ahead of spill for later disposal.
Stable < 100 C hydrolyzed in acidic and alkaline media.
Keep away from substance is hydrolyzed in contact with strong acids and alkalis.
When heated to decomposition it emits very toxic fumes of phosphorus oxides and sulfur oxides.
This compound is a liquid organophosphorus insecticide. Keep unnecessary people away; isolate hazard area and deny entry. Stay upwind; keep out of low areas. Ventilate closed spaces before entering them. Wear positive pressure breathing apparatus and special protective clothing. Remove and isolate contaminated clothing at the site. Move container from fire area if you can do so without risk. Fight fire from maximum distance. Dike fire control water for later disposal; do not scatter the material.Extinguish with dry chemical, carbon dioxide, water spray, fog, or foam.
Liquid formulations may be flammable if a flammable solvent is used. The solid may burn but is difficult to ignite.
When this material is heated to decomposition, it can emit highly toxic fumes of phosphorus oxides.
Emits oxides of phosphorus fumes when burned.
TLV: ppm; 0.1 mg/m3 (as TWA) (skin) (ACGIH 1996). NIOSH REL: TWA 0.1 mg/m3 skin
Fever, low heart rate and abnormally low blood pressure, or rapid heart rate and elevated blood pressure may occur. Headache, dizziness, muscle spasms and profound weakness are common. Alterations of level of consciousness, anxiety, paralysis, seizures and coma may occur. Seizures may be more common in children.
Vomiting, hypersalivation, diarrhea, fecal incontinence and abdominal pain may occur.
Dyspnea, rales, bronchorrhea, bronchospasm, or tachypnea may be noted. Noncardiogenic pulmonary edema may occur in severe cases. Chemical pneumonitis may be seen.
Sweating is a consistent but not universal sign.
Constriction of the pupil, tearing, and blurred vision are common. Prolonged dialation of the pupils may occur in severe poisonings. Opsoclonus has been reported in one case. Salivation commonly occurs.
Seek medical assistance.
Move victim to fresh air. Apply artificial respiration if victim is not breathing. Do not use mouth-to-mouth method if victim ingested or inhaled the substance; induce artificial respiration with the aid of a pocket mask equipped with a one-way valve or other proper respiratory medical device. Administer oxygen if breathing is difficult.
Remove and isolate contaminated clothing and shoes. Immediately flush with running water for at least 20 minutes. For minor skin contact, avoid spreading material on unaffected skin.
Immediately flush with running water for at least 20 minutes.
I; II; III
USCG CHRIS Code