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METHAMIDOPHOS
ICSC: 0176
Peer-Review Status: 27.10.1994 Validated
O,S-Dimethyl phosphoramidothioate
Phosphoramidothioic acid, O,S-dimethyl este 
CAS #: 10265-92-6 RTECS #: TB4970000
UN #: 2783
EC #: 015-095-00-4
EINECS #: 233-606-0
    Formula: C2H8NO2PS
Molecular mass: 141.1

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.  Use water spray, powder, alcohol-resistant foam, 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. Unconciousness. Weakness. Pupillary constriction, muscle cramp, excessive salivation. See Ingestion.  Use 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.  Wear 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 refer for medical attention. 
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. Rest. Refer for medical attention . 

SPILLAGE DISPOSAL
PACKAGING & LABELLING
Personal protection: complete protective clothing including self-contained breathing apparatus. Do NOT wash away into sewer. Sweep spilled substance into covered sealable containers. If appropriate, moisten first to prevent dusting. Carefully collect remainder. Then store and dispose of according to local regulations.  Unbreakable packaging.
Put breakable packaging into closed unbreakable container.
Do not transport with food and feedstuffs.
Marine pollutant. 
EC Classification
Symbol: T+, N; R: 24-26/28-50; S: (1/2)-28-36/37-45-61 
UN Classification
UN Hazard Class: 6.1; UN Pack Group: II 
GHS Classification
Fatal if swallowed, in contact with skin or if inhaled
Causes eye irritation
Causes damage to central nervous system
Causes damage to the central nervous system through prolonged or repeated exposure
Very toxic to aquatic life
Toxic to aquatic life with long lasting effects 
skull;toxiccancer;health hazenviro;aqua

EMERGENCY RESPONSE SAFE STORAGE
  Provision to contain effluent from fire extinguishing. Separated from food and feedstuffs. Dry. Keep in a well-ventilated room. 

IMPORTANT DATA
Physical State; Appearance
COLOURLESS CRYSTALS. 

Physical dangers
 

Chemical dangers
Decomposes on heating and on burning. This produces toxic and irritating fumes including nitrogen oxides, phosphorus oxides and sulfur 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 20°C 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 is irritating to the eyes. The substance may cause effects on the central nervous system. This may result in convulsions and respiratory failure. Cholinesterase inhibition. Exposure could cause 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. This may result in delayed neuropathy. Cholinesterase inhibition. Cumulative effects are possible. See Acute Hazards/Symptoms. 


PHYSICAL PROPERTIES ENVIRONMENTAL DATA
Melting point: 44°C
Relative density (water = 1): 1.3
Solubility in water: good
Vapour pressure, Pa at 20°C: 0.002
Octanol/water partition coefficient as log Pow: -0.66  
This substance may be hazardous to the environment. Special attention should be given to birds, bees and fish. 

NOTES
Use of alcoholic beverages enhances the harmful effect.
Depending on the degree of exposure, periodic medical examination is suggested.
Specific treatment is necessary in case of poisoning with this substance; the appropriate means with instructions must be available.
Do NOT take working clothes home.
If the substance is formulated with solvents also consult the ICSCs of these materials.
Carrier solvents used in commercial formulations may change physical and toxicological properties.
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.
Card has been partially updated in January 2008: see Ingestion First Aid.
Card has been partially updated in April 2013: see GHS classification. 

ADDITIONAL INFORMATION
 

IPCS
International
Programme on
Chemical Safety
WHO ILO EC Prepared in the context of cooperation between the International Programme on Chemical Safety and the European Commission
© IPCS 2004-2012
LEGAL NOTICE Neither the EC nor the IPCS nor any person acting on behalf of the EC or the IPCS is responsible for the use which might be made of this information.


    See Also:
       Toxicological Abbreviations
       Methamidophos (HSG 79, 1993)
       Methamidophos (JMPR Evaluations 2002 Part II Toxicological)
       Methamidophos (Pesticide residues in food: 1976 evaluations)
       Methamidophos (Pesticide residues in food: 1979 evaluations)
       Methamidophos (Pesticide residues in food: 1981 evaluations)
       Methamidophos (Pesticide residues in food: 1982 evaluations)
       Methamidophos (Pesticide residues in food: 1984 evaluations)
       Methamidophos (Pesticide residues in food: 1985 evaluations Part II Toxicology)
       Methamidophos (Pesticide residues in food: 1990 evaluations Toxicology)