• Carbethoxy malaoxon
  • S-(1,2-Diethoxycarbonyl)ethyl O,O-dimethyl phosphorothioate
  • O,O-Dimethyl s-1,2-bis(Ethoxycarbonyl)ethyl phosphorothioate
  • O,O-Dimethyl s-(1,2-dicarbethoxy)ethyl phosphorothioate
  • Liromat
  • Malaoxone
Colorless viscous oily liquid with a weak unpleasant odor.
Srp: malaoxon is a biochemical or photolytic product of malathion.

Registry Numbers and Inventories.
RTECS class
Tumorigen; Drug; Mutagen; Reproductive Effector
Beilstein Reference

Formula mass
Boiling point, °C
Vapor pressure, mmHg
0.00004 (30 C)
1.231 g/cm3 (20 C)
Refractive index
1.4667 (23 C)
Partition coefficient, pKow

Hazards and Protection.
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.
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.
If Tyvek-type disposable protective clothing is not worn during handling of this chemical, wear disposable Tyvek-type sleeves taped to your gloves.
When working with this chemical, wear a NIOSH-approved full face chemical cartridge respirator equipped with the appropriate organic vapor cartridges. If that is not available, a half face respirator similarly equipped plus airtight goggles can be substituted. However, please note that half face respirators provide a substantially lower level of protection than do full face respirators.
Small spills/leaks
If you spill this chemical, FIRST REMOVE ALL SOURCES OF IGNITION. Then, use absorbent paper to pick up all liquid spill material. Your contaminated clothing and absorbent paper should be sealed in a vapor-tight plastic bag for eventual disposal. Solvent wash all contaminated surfaces with 60-70% ethanol followed by washing with a soap and water solution. Do not reenter the contaminated area until the Safety Officer (or other responsible person) has verified that the area has been properly cleaned.
No data.
Strong oxidizing acids may cause a vigorous reaction that is sufficiently exothermic to ignite the reaction products.

Fire fighting
Fires involving this material can be controlled with a dry chemical, carbon dioxide or Halon extinguisher. A water spray may also be used.
Fire potential
This chemical is probably combustible.

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. Sporadic reports of human birth defects related to organophosphates have not been fully verified.
Nausea, vomiting, abdominal cramps, and diarrhea are common muscarinic effects. Both painless and frank clinical pancreatitis have been reported.
Increased bronchial secretions, bronchospasm and dyspnea occur in moderate to severe exposures. Respiratory failure and non-cardiogenic pulmonary edema may occur with severe poisonings. Acute respiratory insufficiency is the main cause of death in acute poisonings. The hydrocarbon vehicle may cause chemical pneumonitis.
Constriction of the pupil, tearing, and blurred vision are common. Prolonged dialation of the pupils may occur. Salivation commonly occurs.

First aid
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.
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.
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.
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.