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METHYL PARATHION
ICSC: 0626
Peer-Review Status: 19.10.2005 Validated
O,O-Dimethyl O-4-nitrophenyl phosphorothioate
O,O-Dimethyl-p-nitrophenylthionophosphate
Phosphorothioic acid, O,O-dimethyl O-(4-nitrophenyl) ester 
CAS #: 298-00-0 RTECS #: TG0175000
UN #: 2783
EC #: 015-035-00-7
EINECS #: 206-050-1
    Formula: C8H10NO5PS
Molecular mass: 263.2

TYPES OF
HAZARD /
EXPOSURE
ACUTE HAZARDS / SYMPTOMS      PREVENTION      FIRST AID / FIRE FIGHTING
FIRE Combustible. 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, foam, powder, carbon dioxide. 
EXPLOSION      
 
EXPOSURE   PREVENT DISPERSION OF DUST! STRICT HYGIENE! AVOID EXPOSURE OF ADOLESCENTS AND CHILDREN!  IN ALL CASES CONSULT A DOCTOR! 
Inhalation Sweating. Nausea. Vomiting. Dizziness. Pupillary constriction, muscle cramp, excessive salivation. Muscle twitching. Laboured breathing. Diarrhoea. Convulsions. Unconciousness. Symptoms may be delayed. See Notes.  Use local exhaust or breathing protection.  Fresh air, rest. Artificial respiration may be needed. Refer for medical attention. 
Skin MAY BE ABSORBED! See Inhalation.  Protective gloves. Protective clothing.  Remove contaminated clothes. Rinse and then wash skin with water and soap. Refer for medical attention . 
Eyes 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 See Inhalation.  Do not eat, drink, or smoke during work. Wash hands before eating.  Induce vomiting (ONLY IN CONSCIOUS PERSONS!). See Notes. Give a slurry of activated charcoal in water to drink. Refer immediately for medical attention. 

SPILLAGE DISPOSAL
PACKAGING & LABELLING
Personal protection: chemical protection suit including self-contained breathing apparatus. Do NOT let this chemical enter the environment. Sweep spilled substance into covered containers. If appropriate, moisten first to prevent dusting. Carefully collect remainder. Then store and dispose of according to local regulations.  Do not transport with food and feedstuffs.
Severe marine pollutant. 
EC Classification
Symbol: T+, N; R: 5-10-24-26/28-48/22-50/53; S: (1/2)-28-36/37-45-60-61 
UN Classification
UN Hazard Class: 6.1; UN Pack Group: II 
GHS Classification
 

EMERGENCY RESPONSE SAFE STORAGE
Transport Emergency Card: TEC (R)-61GT7-II.  Store in an area without drain or sewer access. Keep in a well-ventilated room. Separated from food and feedstuffs. 

IMPORTANT DATA
Physical State; Appearance
COLOURLESS-TO-WHITE SOLID IN VARIOUS FORMS. 

Physical dangers
 

Chemical dangers
Decomposes on heating. This produces toxic fumes including nitrogen oxides, phosphorus oxides and sulfur oxides. This generates fire and explosion hazard. 

Occupational exposure limits
TLV: 0.2mg/m³ as TWA; (skin); A4 (not classifiable as a human carcinogen); BEI issued; (ACGIH 2005). 

Routes of exposure
The substance can be absorbed into the body by inhalation of its aerosol, through the skin and by ingestion. 

Inhalation risk
A harmful concentration of airborne particles can be reached quickly on spraying or when dispersed, especially if powdered. 

Effects of short-term exposure
The substance may cause effects on the nervous system. This may result in convulsions and respiratory depression. Cholinesterase inhibition. Exposure far above the OEL could cause death. Medical observation is indicated. 

Effects of long-term or repeated exposure
Cholinesterase inhibition. Cumulative effects are possible. See Acute Hazards/Symptoms. 


PHYSICAL PROPERTIES ENVIRONMENTAL DATA
Decomposes at 120°C
Melting point: 35-38°C
Density: 1.4 g/cm³
Solubility in water, g/100ml: 0.006
Vapour pressure, Pa at 20°C: 0.001
Octanol/water partition coefficient as log Pow: 2-3  
The substance is very toxic to aquatic organisms. This substance may be hazardous to the environment. Special attention should be given to birds and bees. This substance does enter the environment under normal use. Great care, however, should be taken to avoid any additional release, for example through inappropriate disposal. 

NOTES
If the pesticide is present in a formulation containing hydrocarbon solvents, vomiting should not be induced.
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.
Carrier solvents used in commercial formulations may change physical and toxicological properties.
Do NOT take working clothes home. 

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
       Methyl parathion (EHC 145, 1992)
       Methyl parathion (HSG 75, 1992)
       Methyl Parathion (FAO Meeting Report PL/1965/10/1)
       Methyl Parathion  (IARC Summary & Evaluation, Supplement7, 1987)
       Methyl Parathion (IARC Summary & Evaluation, Volume 30, 1983)