Phosmet

  • O,O-Dimethyl S-phthalimidomethyl phosphorodithioate
  • Phosphorodithioic acid, S-((1,3-dihydro-1,3-dioxo-2H-isoindol-2-yl)methyl) O,O-dimethyl ester
  • O,O-Dimethyl phosphorodithioate s ester with n-(Mercaptomethyl) phthalimide
Formula
C11H12NO4PS2
Structure
Description
Off-white crystalline solid with an offensive odor.
Uses
Insecticide for hornflies on beef cattle & for cattle grubs, for weevils on sweet potatoes in storage & on alfalfa.

Registry Numbers and Inventories.
CAS
732-11-6
EC (EINECS/ELINCS)
211-987-4
EC Index Number
015-101-00-5
EC Class
Harmful
RTECS
TE2275000
RTECS class
Agricultural Chemical and Pesticide; Mutagen; Reproductive Effector; Human Data
UN (DOT)
2783
Merck
12,7492
Beilstein/Gmelin
264869
Beilstein Reference
4-21-00-05123
EPA OPP
59201
Swiss Giftliste 1
G-4058
Austrailia AICS
Listed
New Zealand
Listed
Korea ECL
Listed

Properties.
Formula
C11H12NO4PS2
Formula mass
317.33
Melting point, °C
72 - 73
Boiling point, °C
413
Vapor pressure, mmHg
5E-7 (25 C)
Vapor density (air=1)
10.9
Density
1.03 g/cm3 (20 C)
Solubility in water
Slightly soluble
Partition coefficient, pKow
2.83
Heat of vaporization
66.5 kJ/mol

Hazards and Protection.
Storage
Keep in a cool, dry, dark location in a tightly sealed container or cylinder. Keep away from incompatible materials, ignition sources and untrained individuals. Secure and label area. Protect containers/cylinders from physical damage.
Handling
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.
Protection
Hat, long-sleeved shirt, long-legged trousers or coveralls, chemical-resistant gloves for mixing.
Respirators
Wear positive pressure self-contained breathing apparatus (SCBA).
Small spills/leaks
Caution : Phosmet may produce toxic gases when heated; containers may explode in the heat of fire. Avoid sources of extreme heat. This is an organophosphorus pesticide. As for other organophosphorus pesticides 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. Use water spray to reduce vapors. Take up small spills with sand or other noncombustible absorbent material and place in containers for later disposal. Take up small, dry spills with clean shovel and place in clean, dry container. Dike far ahead of large spills for later disposal.
Stability
No data.
Incompatibilities
Incompatible with other pesticides under alkaline conditions.
Decomposition
When heated to decomposition it emits very toxic fumes of nitrogen oxides, phosphorus oxides and sulfur oxides.

Fire.
Flash Point,°C
203
Fire fighting
(Non-Specific -- Organophosphorus Pesticide, n.o.s.). Stay upwind; keep out of low areas. Move container from fire area if you can do it without risk. Fight fire from maximum distance. Dike fire control water for later disposal; do not scatter material. Wear positive pressure breathing apparatus and special protective clothing.(Non-Specific -- Organophosphorus Pesticide, n.o.s.) This material may burn but does not ignite readily. For small fires, use dry chemical, carbon dioxide, water spray, or foam. For large fires, use water spray, fog, or foam.
Fire potential
This material may burn but does not ignite readily. Organophosphorus pesticide nos
Hazards
Containers may explode when heated.
Combustion products
Fire may produce irritating, corrosive and/or toxic gases.

Health.
Poison_Class
3
Exposure effects
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.
   Ingestion
Vomiting, hypersalivation, diarrhea, fecal incontinence and abdominal pain may occur.
   Inhalation
Dyspnea, rales, bronchorrhea, bronchospasm, or tachypnea may be noted. Noncardiogenic pulmonary edema may occur in severe cases. Chemical pneumonitis may be seen.
   Skin
Sweating is a consistent but not universal sign.
   Eyes
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. Phosmet is mildly irritating to the eyes.

First aid
 
   Ingestion
Seek medical assistance.
   Inhalation
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.
   Skin
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.
   Eyes
Immediately flush with running water for at least 20 minutes.

Transport.
UN number
2783
Response guide
Hazard class
6.1
Packing Group
I; II; III
 
USCG CHRIS Code
PHM