DEMETON-S-METHYL

Pale yellow oil. Used as an insecticide. Not registered as a pesticide in the U.S. (EPA, 1998)

none

No rapid reaction with air. No rapid reaction with water.

When heated to decomposition, it emits very toxic fumes of oxides of phosphorus and sulfur. This compound is a liquid organophosphorus insecticide. This material may burn but does not ignite readily. Container may explode in heat of fire. Fire may produce irritating or poisonous gases. Runoff from fire control water may give off poisonous gases. Hydrolyzed by alkali. (EPA, 1998)

It inhibits the nervous system and is absorbed readily through the skin. This compound is a liquid organophosphorus insecticide. Poisonous; may be fatal if inhaled, swallowed or absorbed through skin. Contact may cause burns to skin and eyes. (EPA, 1998)

Organophosphates, such as DEMETON-S-METHYL, are susceptible to formation of highly toxic and flammable phosphine gas in the presence of strong reducing agents such as hydrides. Partial oxidation by oxidizing agents may result in the release of toxic phosphorus oxides.

• Esters, Sulfate Esters, Phosphate Esters, Thiophosphate Esters, and Borate Esters
• Sulfides, Organic

No information available.

Excerpt from 152 [Substances - Toxic (Combustible)]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids.

SPILL: Increase the immediate precautionary measure distance, in the downwind direction, as necessary.

FIRE: If tank, rail car or tank truck is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2020)

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. (EPA, 1998)

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. (EPA, 1998)

For emergency situations, wear a positive pressure, pressure-demand, full facepiece self-contained breathing apparatus (SCBA) or pressure- demand supplied air respirator with escape SCBA and a fully-encapsulating, chemical resistant suit. (EPA, 1998)

No information available.

Warning: Demeton-s-methyl is readily absorbed through the skin.

Note: Demeton-s-methyl is a cholinesterase inhibitor.

Signs and Symptoms of Acute Demeton-S-Methyl Exposure: Acute exposure to demeton-S-methyl may produce the following signs and symptoms: pinpoint pupils, blurred vision, headache, dizziness, muscle spasms, and profound weakness. Vomiting, diarrhea, abdominal pain, seizures, and coma may also occur. The heart rate may decrease following oral exposure or increase following dermal exposure. Hypotension (low blood pressure) is not uncommon. Respiratory symptoms include dyspnea (shortness of breath), respiratory depression, and respiratory paralysis. Psychosis may occur.

Emergency Life-Support Procedures: Acute exposure to demeton-S-methyl may require decontamination and life support for the victims. Emergency personnel should wear protective clothing appropriate to the type and degree of contamination. Air-purifying or supplied-air respiratory equipment should also be worn, as necessary. Rescue vehicles should carry supplies such as plastic sheeting and disposable plastic bags to assist in preventing spread of contamination.

Inhalation Exposure:
1. Move victims to fresh air. Emergency personnel should avoid self-exposure to demeton-S-methyl.
2. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer oxygen or other respiratory support.
3. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures.
4. Transport to a health care facility.

Dermal/Eye Exposure:
1. Remove victims from exposure. Emergency personnel should avoid self- exposure to demeton-S-methyl.
2. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer oxygen or other respiratory support.
3. Remove contaminated clothing as soon as possible.
4. If eye exposure has occurred, eyes must be flushed with lukewarm water for at least 15 minutes.
5. Wash exposed skin areas three times with soap and water.
6. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures.
7. Transport to a health care facility.

Ingestion Exposure:
1. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer oxygen or other respiratory support.
2. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures.
3. Vomiting may be induced with syrup of Ipecac. If elapsed time since ingestion of demeton-s-methyl is unknown or suspected to be greater than 30 minutes, do not induce vomiting and proceed to Step
4.Ipecac should not be administered to children under 6 months of age.Warning: Ingestion of demeton-s-methyl may result in sudden onset of seizures or loss of consciousness. Syrup of Ipecac should be administered only if victims are alert, have an active gag-reflex, and show no signs of impending seizure or coma. If ANY uncertainty exists, proceed to Step
4.The following dosages of Ipecac are recommended: children up to 1 year old, 10 mL (1/3 oz); children 1 to 12 years old, 15 mL (1/2 oz); adults, 30 mL (1 oz). Ambulate (walk) the victims and give large quantities of water. If vomiting has not occurred after 15 minutes, Ipecac may be readministered. Continue to ambulate and give water to the victims. If vomiting has not occurred within 15 minutes after second administration of Ipecac, administer activated charcoal.
4. Activated charcoal may be administered if victims are conscious and alert. Use 15 to 30 g (1/2 to 1 oz) for children, 50 to 100 g (1-3/4 to 3-1/2 oz) for adults, with 125 to 250 mL (1/2 to 1 cup) of water.
5. Promote excretion by administering a saline cathartic or sorbitol to conscious and alert victims. Children require 15 to 30 g (1/2 to 1 oz) of cathartic; 50 to 100 g (1-3/4 to 3-1/2 oz) is recommended for adults.
6. Transport to a health care facility. (EPA, 1998)

• BAY 18436
• BAYER 25/154
• DEMETON-S-METHYL
• DIMETHYL S-(2-ETHTHIOETHYL) THIOPHOSPHATE
• ETHANETHIOL, 2-(ETHYLTHIO)-, S-ESTER WITH O,O-DIMETHYL PHOSPHOROTHIOATE
• ISOMETASYSTOX
• ISOMETHYLSYSTOX
• METAISOSEPTOX
• METAISOSYSTOX
• METASYSTOX 55
• METASYSTOX FORTE
• METASYSTOX I
• METASYSTOX J
• METASYSTOX(I)
• METHYL DEMETON THIOESTER
• METHYL ISOSYSTOX
• METHYL-MERCAPTOFOS TEOLOVY
• METHYLTHIONODEMETON
• O,O-DIMETHYL 2-ETHYLMERCAPTOETHYL THIOPHOSPHATE, THIOLO ISOMER
• O,O-DIMETHYL S-(2-(ETHYLTHIO)ETHYL) PHOSPHOROTHIOATE
• O,O-DIMETHYL S-(2-ETHTHIOETHYL) PHOSPHOROTHIOATE
• O,O-DIMETHYL S-(ETHYLMERCAPTO)ETHYL THIOPHOSPHATE
• O,O-DIMETHYL S-2-(ETHYLTHIO)ETHYL PHOSPHOROTHIOATE
• PHOSPHOROTHIOIC ACID, O,O-DIMETHYL S-(2-(ETHYLTHIO)ETHYL) ESTER
• PHOSPHOROTHIOIC ACID, S-(2-(ETHYLTHIO)ETHYL) O,O-DIMETHYL ESTER
• S-(2-(ETHYLTHIO)ETHYL) DIMETHYL PHOSPHOROTHIOLATE
• S-(2-(ETHYLTHIO)ETHYL) O,O-DIMETHYL PHOSPHOROTHIOATE
• S-(2-(ETHYLTHIO)ETHYL) O,O-DIMETHYL THIOPHOSPHATE
• S-[2-(ETHYLTHIO)ETHYL] O,O-DIMETHYL PHOSPHOROTHIOATE
• S-[2-(ETHYLTHIO)ETHYL] O,O-DIMETHYL THIOPHOSPHATE
• THIOMETON OXON