Malathion

  • S-1,2-bis(Ethoxycarbonyl)ethyl O,O-dimethylphosphorodithioate
  • Butanedioic acid, {(dimethoxyphosphinothioyl)thio}-, diethyl ester
Formula
C10H19O6PS2
Structure
Description
Yellow to dark-brown liquid with a skunk-like odor.
Uses
Insecticide.

Registry Numbers and Inventories.
CAS
121-75-5
EC (EINECS/ELINCS)
204-497-7
EC Index Number
015-041-00-X
EC Class
Harmful
RTECS
WM8400000
RTECS class
Agricultural Chemical and Pesticide; Tumorigen; Mutagen; Reproductive Effector; Human Data
UN (DOT)
3082
Merck
12,5740
Beilstein/Gmelin
1804525
Beilstein Reference
4-03-00-01136
EPA OPP
57701
Swiss Giftliste 1
G-2004
Canada DSL/NDSL
DSL
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
C10H19O6PS2
Formula mass
330.36
Melting point, °C
2.8
Boiling point, °C
156
Vapor pressure, mmHg
0.0000353 (25 C)
Vapor density (air=1)
1.23
Odor Threshold Odor threshold 13.5 mg/m3
Density
1.232 g/cm3 (20 C)
Solubility in water
200 mg/L
Surface tension
37.1 g/s2 @ 24 C
Refractive index
1.5002 (23 C)
Partition coefficient, pKow
2.36

Hazards and Protection.
Storage
Keep in well ventilated area. Protect containers against physical damage. Preferably store outdoors or in detached area, otherwise use standard combustible liquid storage room.
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
Wear appropriate protective gloves, clothing and goggles.
Respirators
Wear positive pressure self-contained breathing apparatus (SCBA).
Small spills/leaks
Neutralizing Agents for Acids and Caustics: Liquid bleach solution for decontamination.
Stability
Stable.
Incompatibilities
Avoid contact with strong oxidizers, magnesium, alkaline pesticides.
Decomposition
Above 100 C, decomposes. Explosively. Starts to decompose at 49 C (140 F). When heated to decomposition it emits toxic fumes of phosphoxides and sulfoxides. Decomposed by acids and alkalis.

Fire.
Flash Point,°C
>162
Fire fighting
Fire Extinguishing Agents: Dry chemical, carbon dioxide, water spray, foam
Fire potential
Combustible, but it may take some effort to ignite.
Hazards
Containers may explode when heated.
Combustion products
Vapors and fumes from fires are hazardous.

Health.
Exposure limit(s)
TLV: ppm; 10 mg/m3 (skin) (ACGIH 1994). OSHA PEL: TWA 15 mg/m3 skin NIOSH REL: TWA 10 mg/m3 skin NIOSH IDLH: 250 mg/m3
Poison_Class
3
Exposure effects
Reduced body temperature or elevated body temperature may occur. Low heart rate and abnormally low blood pressure may develop after moderate to severe poisoning. Rapid heart rate, elevated blood pressure, and changes in respiratory rate may also occur. Early giddiness, anxiety headache, and restlessness followed by ataxia, drowsiness, and confusion are common with moderate to severe exposures. Fasciculations, profound weakness, coma and seizures may develop in severe cases. CNS depression and seizures may be more common in children than adults. Most organophosphates are not teratogenic in animals, but some cause lower fetal birth weights and/or higher neonatal mortality. <br>Sporadic reports of human birth defects related to organophosphates have not been fully verified.
   Ingestion
Nausea, vomiting, abdominal cramps, and diarrhea are common muscarinic effects. Both painless and frank clinical pancreatitis have been reported.
   Inhalation
Inhalation of material may be harmful.
   Skin
Profuse sweating is common. Pallor may be noted. Dermal sensitization has been reported.
   Eyes
Constriction of the pupil, tearing, and blurred vision are common. Prolonged dialation of the pupils may occur. Salivation commonly occurs.

First aid
 
   Ingestion
DO NOT INDUCE VOMITING. If the victim is conscious and not convulsing, administer a slurry of activated charcoal in water and simultaneously call a hospital or poison control center. IMMEDIATELY transport the victim to a hospital.
   Inhalation
IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. IMMEDIATELY call a physician and be prepared to transport the victim to a hospital even if no symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) should be used.
   Skin
IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water. IMMEDIATELY call a hospital or poison control center even if no symptoms (such as redness or irritation) develop. IMMEDIATELY transport the victim to a hospital for treatment after washing the affected areas.
   Eyes
First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.

Transport.
UN number
3082
Response guide
Hazard class
9
Packing Group
III
 
USCG CHRIS Code
MLT