Demeton-S-methyl

  • S-2-Ethylthioethyl O,O-dimethyl phosphorothioate
  • Phosphorothioic acid, S-(2-(ethylthio)ethyl)O,O-dimethyl ester
Formula
C6H15O3PS2
Structure
Description
Pale yellow oil.
Uses
Controls aphid vectors of virus diseases, white-flies, leafhoppers, and sawflies. Duratox is used for the control of aphids, red spider mites, and certain other pests in arable and market garden crops, fruit, and hops.

Registry Numbers and Inventories.
CAS
919-86-8
EC (EINECS/ELINCS)
213-052-6
EC Index Number
015-031-00-5
EC Class
Toxic; Dangerous for the Environment
RTECS
TG1750000
RTECS class
Agricultural Chemical and Pesticide; Mutagen
UN (DOT)
3018
Beilstein/Gmelin
1707311
Beilstein Reference
4-01-00-02461
Swiss Giftliste 1
G-1481
Canada DSL/NDSL
NDSL
US TSCA
Listed
Austrailia AICS
Listed
Korea ECL
Listed

Properties.
Formula
C6H15O3PS2
Formula mass
230.30
Boiling point, °C
74
Vapor pressure, mmHg
47 (30 C)
Vapor density (air=1)
7.9
Odor Threshold Odor threshold 1.0X10-2 mg/L (detection in water)
Density
1.207 g/cm3 (20 C)
Solubility in water
3.3 g/L
Refractive index
1.511 (20 C)
Partition coefficient, pKow
1.02

Hazards and Protection.
Storage
Rooms used for storage only should be soundly constructed and fitted with secure locks. Floors should be kept clear and pesticides clearly identified if repacking is carried out in storage rooms, adequate light should be available; floors should be impervious and sound. Pesticides pesticides containers must be provided with labels indicating the degree of toxicity of the product they contain. The labels must not only give a short description of how to use the prepn, but also state basic precautions to be taken when applying it. Organophosphorus pesticides pesticides of any degree of toxicity should be transported in containers which are clearly labelled, leak-proof, and not easily damaged. They should never be transported or stored beside, or above any type of food, and all spillages should be immediately reported.
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
Workers handling and applying organophosphate pesticides must be given personal protective equipment comprising overalls made of a tight fabric or polyvinyl chloride, gloves, and rubber boots. The eyes should be protected by goggles.
Respirators
Respiratory protection (supplied-air respirator with full facepiece or self-contained breathing apparatus) should be available where these compounds are manufactured or used and should be worn in case of emergency and overexposure.<BR>Wear a respirator with an activated-carbon gas filter cartridge affording protection for a determined number of working hours.
Small spills/leaks
This compound is a liquid organophosphorus insecticide. 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.
Stability
Demeton-s-methyl is less stable than demeton. 50% Hydrolysis at 70 C requires 1.25 Hr at pH 9 and 4.9 Hr at pH 3.During storage and. In water. About 30% of the o-isomer goes to the s-isomer.
Incompatibilities
Incompatible with alkaline materials.

Fire.
Fire fighting
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.Small fires: dry chemical, carbon dioxide, water spray, or foam. Large fires: water spray, fog or foam. 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.
Fire potential
Combustible material: may burn but does not ignite readily.
Hazards
When heated to decomposition, it emits very toxic fumes of oxides of phosphorus and sulfur. This compound is a liquid organophosphorus insecticide. This material Container may explode in heat of fire. Runoff from fire control water may give off poisonous gases. Hydrolyzed by alkali.
Combustion products
Fire may produce irritating, corrosive and/or toxic gases.

Health.
Poison_Class
2
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.

First aid
 
   Ingestion
Seek medical assistance.
   Inhalation
Move patient to fresh air. Monitor for respiratory distress. If cough or difficulty breathing develops, evaluate for respiratory tract irritation, bronchitis, or pneumonitis. Administer oxygen and assist ventilation as required. Treat bronchospasm with beta2 agonist and corticosteroid aerosols.
   Skin
Systemic effects can occur from dermal exposure to organophosphates. Remove contaminated clothing, wash skin, hair and nails vigorously with repeated soap washings. Leather absorbs pesticides; all contaminated leather should be discarded. Rescue personnel and bystanders should avoid direct contact with contaminated skin, clothing, or other objects.
   Eyes
Irrigate exposed eyes with copious amounts of tepid water for at least 15 minutes. If irritation, pain, swelling, lacrimation, or photophobia persist, the patient should be seen in a health care facility. Patients symptomatic following exposure should be observed in a controlled setting until all signs and symptoms have fully resolved. Suction oral secretions until atropinization. Treatment should include recommendations listed in the oral exposure section when appropriate. Contraindications - succinylcholine and other cholinergic agents are contraindicated. Note: see treatment of eye exposure in the main body of this document for complete information.

Transport.
UN number
3018
Response guide
Hazard class
6.1
Packing Group
I; II; III
 
USCG CHRIS Code
DYL