Chemical Properties
Demeton is a light brown liquid with an odor
of sulfur compounds; freezing/melting point ≤‐13
C
General Description
Oily liquid with an amber color and an odor of sulfur. Used as an agricultural insecticide.
Reactivity Profile
DEMETON may release sulfur oxides and phosphoric acid. Solvent carrier vapors may travel on ground to ignition source. Avoid strong oxidizers. Avoid mixtures with water or polar solvents, in which sulfur is lost to oxygen, air and light, which cause hydrolysis, alkaline mixtures and oxidizing agents. [EPA, 1998].
Health Hazard
DEMETON is a cholinesterase inhibitor. It is readily absorbed through the skinand is extremely toxic. Probable human lethal oral dose is 5-50 mg/kg or 7 drops to 1 teaspoonful for 150 lb. person. Acute dose is believed to be 12 to 20 mg by oral route.
Fire Hazard
May release sulfur oxides and phosphoric acid. Solvent carrier vapors may travel on ground to ignition source. Avoid strong oxidizers. Avoid mixtures with water or polar solvents, in which sulfur is lost to oxygen, air and light, which cause hydrolysis, alkaline mixtures and oxidizing agents.
Potential Exposure
A potential danger to those involved
in the manufacture, formulation, and application of this
systemic insecticide and acaricide.
First aid
Move victim to fresh air. Call 911 or emergency
medical service. Give artificial respiration if victim is not
breathing. Do not use mouth-to-mouth method if victim
ingested or inhaled the substance; give artificial respiration
with the aid of a pocket mask equipped with a one-way valve
or other proper respiratory medical device. Administer oxy-
gen if breathing is difficult. Remove and isolate contami-
nated clothing and shoes. In case of contact with substance,
immediately flush skin or eyes with running water for at
least 20 minutes. For minor skin contact, avoid spreading
material on unaffected skin. Keep victim warm and quiet.
Effects of exposure (inhalation, ingestion, or skin contact) to
substance may be delayed. Ensure that medical personnel are
aware of the material(s) involved and take precautions to
protect themselves. Medical observation is recommended for
24 to 48 hours after breathing overexposure, as pulmonary
edema may be delayed. As first aid for pulmonary edema, a
doctor or authorized paramedic may consider administering
a drug or other inhalation therapy
Shipping
UN3278 Organophosphorus compound, liquid,
toxic, n.o.s., Hazard Class: 6.1; Labels: 6.1-Poisonous
materials, Hazard Technical Name Required, Potential
Inhalation Hazard (Special Provision 5). UN3017
Organophosphorus pesticides, liquid, toxic, flammable,
flash point not , 23
C, Hazard class: 6.1; Labels: 6.1-
Poisonous materials, 3-Flammable liquid. UN2810 Toxic
liquids, organic, n.o.s., Hazard Class: 6.1; Labels: 6.1-
Poisonous materials, Technical Name Required.
Incompatibilities
May form explosive mixture with air.
Strong oxidizers, strong bases, soluble mercury, other
pesticides, and water.
Description
Demeton is an organophosphate insecticide. It has a moderate aqueous solubility and is highly volatile. There are considerable gaps in literature regarding its environmental fate. Demeton is highly toxic to mammals, is a neurotoxin and may adversely affect reproduction and/or development. It is also an acetyl cholinesterase inhibitor. It is highly toxic to birds and aquatic invertebrates. It moderately toxic to fish and honeybees.
Waste Disposal
The thiono-and thiolo-isomers of
this mixture are 50% hydrolyzed in 75 minutes and 0.85 min-
ute, respectively @ 20℃
and pH 13. At pH 9 and 70 ℃
, the
half-life of Demeton is 1.25 hour, but an pH 1-5 it is over
11 hours. Sand and rushed limestone may be added together
with a flammable solvent; the resultant mixture may be burned
in a furnace with afterburner and alkaline scrubber
.In
accordance with 40CFR165, follow recommendations for the
disposal of pesticides and pesticide containers. Must be dis-
posed properly by following package label directions or by
contacting your local or federal environmental control agency,
or by contacting your regional EPA office.
Production Methods
Demeton is commercially produced by reacting O,O-diethyl phosphorochloridothioate with 2-(ethylthio)ethanol to form the organophosphorothioate ester. The synthesis begins with the preparation of O,O-diethyl phosphorochloridothioate, which is then subjected to nucleophilic substitution with 2-(ethylthio)ethanol under controlled conditions, typically in an organic solvent such as toluene or acetone. A base like triethylamine is used to neutralise the hydrochloric acid byproduct and drive the reaction forward. The resulting product is a mixture of Demeton-O and Demeton-S isomers, which may be further purified or used as a technical-grade mixture.
Mechanism of action
Systemic with contact and stomach action. Acetylcholinesterase (AChE) inhibitor.
Pesticide Type
Insecticide; Acaricide
