Parathion

  • Diethyl parathion
  • Ethyl parathion
  • O,O-diethyl-o-(4-Nitrophenyl) phosphorothioate
  • Parathion-Ethyl
  • Phosphorothioic acid O,O-diethyl o-(4-Nitrophenyl) ester
  • Thiophos
Formula C10H14NO5PS
Structure
Description Light-yellow liquid, it turn solid at 6 C, a deadly poison by all routes.
Uses Parathion controls a variety of insects such as aphids, mites, beetles, lepidoptera, leaf hoppers, leafminers, and other pests found on fruits, cotton, vegetables, and forage crops. It also controls several soil insects such as wireworms, rootworms, and symphilids.

Registry Numbers and Inventories.
CAS 56-38-2
EC (EINECS/ELINCS) 200-271-7
EC Index Number 015-034-00-1
EC Class Very toxic; Dangerous for the Environment
RTECS TF4550000
RTECS class Agricultural Chemical and Pesticide; Tumorigen; Mutagen; Reproductive Effector; Human Data
UN (DOT) 2783
Merck 12,7167
Beilstein/Gmelin 2059093
Beilstein Reference 4-06-00-01337
RCRA P089
EPA OPP 57503
Swiss Giftliste 1 G-2073
Austrailia AICS Listed

Odor Threshold Odor threshold 0.476 mg/m3
Properties.
Formula C10H14NO5PS
Formula mass 291.26
Melting point, °C 6
Boiling point, °C 375
Vapor pressure, mmHg 3E-5 (25 C)
Vapor density (air=1) 1.262
Density 1.2704 g/cm3 (20 C)
Solubility in water 10 mg/L
Viscosity 15.30 cp (25 C)
Surface tension 39.2 g/s2 (25 C)
Refractive index 1.53301 (20 C)
Partition coefficient, pKow 3.83
Heat of vaporization 58.5 kJ/mol
Heat of combustion -6190 kJ/mol

Hazards and Protection.
Storage Keep in well ventilated area. Protect against physical damage. Store at in areas where any spillage would not endanger workers or contaminate other materials.
WHMIS D1A D2A
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 chemical protective clothing.
Respirators Wear positive pressure self-contained breathing apparatus.
Small spills/leaks Do not touch damaged containers or spilled material unless wearing appropriate protective clothing. Stop leak if you can do it without risk. Prevent entry into waterways, sewers, basements or confined areas. Cover with plastic sheet to prevent spreading. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. DO NOT GET WATER INSIDE CONTAINERS.
Stability Stable. Decomposes at elevated temperature, and in containers may develop sufficient pressure to rupture.
Incompatibilities Avoid contact with strong oxidizers, alkaline materials. Violent reaction with endrin.
Decomposition Toxic gases and vapors (such as carbon monoxide, oxides of nitrogen, phosphorus and sulfur) may be released when parathion. Undergoes decomposition.

Fire.
Flash Point,°C 174
Fire fighting SMALL FIRES: Dry chemical, carbon dioxide or water spray. LARGE FIRES: Water spray, fog or regular foam. Move containers from fire area if you can do it without risk. Dike fire control water for later disposal; do not scatter the material. Use water spray or fog; do not use straight streams. FIRE INVOLVING TANKS OR CAR/TRAILER LOADS: Fight fire from maximum distance or use unmanned hose holders or monitor nozzles. Do not get water inside containers. Cool containers with flooding quantities of water until well after fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks engulfed in fire. For massive fire, use unmanned hose holders or monitor nozzles; if this is impossible, withdraw from area and let fire burn.
Fire potential May burn but does not ignite readily.
Hazards Containers may explode when heated. Runoff may pollute waterways. Substance may be transported in a molten form.
Combustion products Fire may produce irritating, corrosive and/or toxic gases.
NFPA Health 4
  Flammability 1  
  Reactivity 2  

Health.
Exposure limit(s) TLV: ppm; 0.1 mg/m3 (skin) (ACGIH 1992-1993). PDK: 0.05 mg/m3 P (USSR 1987). OSHA PEL: TWA 0.1 mg/m3 skin NIOSH REL: TWA 0.05 mg/m3 skin NIOSH IDLH: 10 mg/m3
Exposure effects Vital sign changes can include slow or rapid heart rate, abnormally low blood pressure or elevated blood pressure, rapid breathing, respiratory paralysis or fever. Headache, dizziness, muscle spasms, profound weakness, paralysis, confusion, slurred speech and loss of reflexes are common symptoms of dichlorvos overexposure. Altered level of consciousness, seizures and coma may occur. Seizures may be more common in children.
   Ingestion Vomiting, diarrhea, fecal incontinence, pancreatitis and abdominal pain may occur, especially from percutaneous and inhalation exposures.
   Inhalation Dyspnea, rales, bronchorrhea, or tachypnea may be noted. Pulmonary edema may occur in severe cases.
   Skin Sweating is a consistent but not universal sign.
   Eyes Constriction of the pupil, tearing, blurred vision and salivation are common. Prolonged dialation of the pupils may occur in severe poisonings.

First aid		  
   Ingestion Seek medical assistance.
   Inhalation Move victim to fresh air. Apply artificial respiration if victim is not breathing. Do not use mouth-to-mouth method if victim ingested or inhaled the substance; induce artificial respiration with the aid of a pocket mask equipped with a one-way valve or other proper respiratory medical device. Administer oxygen if breathing is difficult.
   Skin Remove and isolate contaminated clothing and shoes. Immediately flush with running water for at least 20 minutes. For minor skin contact, avoid spreading material on unaffected skin.
   Eyes Immediately flush with running water for at least 20 minutes.

Transport.
UN number 2783
Response guide 152
Hazard class 6.1
Packing Group I; II; III  
USCG CHRIS Code PTO  
Std. Transport # 4921470