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METHAMIDOPHOS ICSC: 0176
Date of peer-review: October 1994

O,S-Dimethyl phosphoramidothioate
Phosphoramidothioic acid, O,S-dimethyl ester
CAS # 10265-92-6 C2H8NO2PS
RTECS # TB4970000 Molecular mass: 141.1
UN # 2783
EC # 015-095-00-4
TYPES OF HAZARD / EXPOSURE ACUTE HAZARDS / SYMPTOMS PREVENTION FIRST AID / FIRE FIGHTING
FIRE Combustible under specific conditions. Liquid formulations containing organic solvents may be flammable. Gives off irritating or toxic fumes (or gases) in a fire.
NO open flames.
Powder, alcohol-resistant foam, water spray, carbon dioxide.
EXPLOSION Risk of fire and explosion if formulations contain flammable/explosive solvents.


EXPOSURE
PREVENT DISPERSION OF DUST! STRICT HYGIENE! AVOID EXPOSURE OF ADOLESCENTS AND CHILDREN!

Inhalation Dizziness. Sweating. Laboured breathing. Unconsciousness. Weakness. Pupillary constriction, muscle cramp, excessive salivation. (See Ingestion).
Ventilation (not if powder), local exhaust, or breathing protection.
Fresh air, rest. Half-upright position. Refer for medical attention. See Notes.
Skin MAY BE ABSORBED! (Further see Inhalation).
Protective gloves. Protective clothing.
Remove contaminated clothes. Rinse skin with plenty of water or shower. Refer for medical attention. (See Notes).
Eyes Redness. Pain. Blurred vision.
Face shield, or eye protection in combination with breathing protection if powder.
First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then take to a doctor.
Ingestion Abdominal cramps. Convulsions. Diarrhoea. Nausea. Vomiting. Muscle twitching. (Further see Inhalation).
Do not eat, drink, or smoke during work. Wash hands before eating.
Rinse mouth. Give a slurry of activated charcoal in water to drink. Induce vomiting (ONLY IN CONSCIOUS PERSONS!). Rest. Refer for medical attention. See Notes.
SPILLAGE DISPOSAL PACKAGING & LABELLING
Do NOT wash away into sewer. Sweep spilled substance into sealable containers; if appropriate, moisten first to prevent dusting. Carefully collect remainder, then remove to safe place. (Extra personal protection: complete protective clothing including self-contained breathing apparatus).
Unbreakable packaging; put breakable packaging into closed unbreakable container. Do not transport with food and feedstuffs. Marine pollutant.
EU Classification
Symbol: T+
R: 24-28-36
S: (1/2-)22-28-36/37-45
UN Classification
UN Hazard Class: 6.1
UN Pack Group: II
EMERGENCY RESPONSE STORAGE
Transport Emergency Card: TEC (R)-61G41b
Provision to contain effluent from fire extinguishing. Separated from food and feedstuffs. Dry. Keep in a well-ventilated room.
IPCS
International
Programme on
Chemical Safety
Prepared in the context of cooperation between the International Programme on Chemical Safety and the Commission of the European Communities IPCS, CEC 2001

SEE IMPORTANT INFORMATION ON BACK


METHAMIDOPHOS ICSC: 0176
IMPORTANT DATA
PHYSICAL STATE; APPEARANCE:
COLOURLESS CRYSTALS.

CHEMICAL DANGERS:
The substance decomposes on heating and on burning producing toxic and irritating fumes including nitrogen oxides, sulfur oxides, and phosphorous oxides. Attacks mild steel and copper-containing alloys (technical grade).

OCCUPATIONAL EXPOSURE LIMITS:
TLV not established.
ROUTES OF EXPOSURE:
The substance can be absorbed into the body by inhalation, through the skin and by ingestion.

INHALATION RISK:
Evaporation at 20C is negligible; a harmful concentration of airborne particles can, however, be reached quickly on spraying or when dispersed, especially if powdered.

EFFECTS OF SHORT-TERM EXPOSURE:
The substance irritates the eyes. The substance may cause effects on the central nervous system, resulting in convulsions, respiratory failure. Cholinesterase inhibitor. Exposure may result in death. The effects may be delayed. Medical observation is indicated.

EFFECTS OF LONG-TERM OR REPEATED EXPOSURE:
The substance may have effects on the nervous system, resulting in delayed neuropathy. Cholinesterase inhibitor; cumulative effect is possible: see acute hazards/symptoms.
PHYSICAL PROPERTIES
Melting point: 44C
Relative density (water = 1): 1.3
Solubility in water: good
Vapour pressure, Pa at 20C: 0.002
Octanol/water partition coefficient as log Pow: -0.66
ENVIRONMENTAL DATA
This substance may be hazardous to the environment; special attention should be given to birds, honey bees and fish.
NOTES
Use of alcoholic beverages enhances the harmful effect. Depending on the degree of exposure, periodic medical examination is indicated. Specific treatment is necessary in case of poisoning with this substance; the appropriate means with instructions must be available. If the substance is formulated with solvent(s) also consult the card(s) (ICSC) of the solvent(s). Carrier solvents used in commercial formulations may change physical and toxicological properties. Do NOT take working clothes home. Bay 71628, Monitor, Pillaron, SRA 5172 and Tamaron are trade names. If the substance is present under the form of a formulation containing hydrocarbon solvents, vomiting may not be induced.
ADDITIONAL INFORMATION


LEGAL NOTICE Neither the CEC nor the IPCS nor any person acting on behalf of the CEC or the IPCS is responsible for the use which might be made of this information
IPCS, CEC 2001

See Also:
        Methamidophos (PIM 798)