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Parathion-methyl

Parathion-methyl Structure
CAS No.
298-00-0
Chemical Name:
Parathion-methyl
Synonyms
METHYL PARATHION;METACIDE;quinophos;CEKUMETHION;methylparathion (esa,jmaf);DALF;e601;a-gro;ME605;Dalif
CBNumber:
CB3348228
Molecular Formula:
C8H10NO5PS
Molecular Weight:
263.21
MOL File:
298-00-0.mol
Modify Date:
2024/3/14 15:18:26

Parathion-methyl Properties

Melting point 36°C
Boiling point 143°C (1.0 mmHg)
Density 1.36
vapor pressure 4.1×10-4 Pa (20 °C)
refractive index nD25 1.5367
Flash point 46.1°C
storage temp. APPROX 4°C
solubility Chloroform: Slightly Soluble,Methanol: Slightly Soluble
form solid
Water Solubility 0.005 g/100 mL
BRN 8905814
Stability Stable. Flammable.
CAS DataBase Reference 298-00-0(CAS DataBase Reference)
IARC 3 (Vol. 30, Sup 7) 1987
NIST Chemistry Reference Phosphorothioic acid, o,o-dimethyl-o-p-nitrophenyl ester(298-00-0)
EPA Substance Registry System Methyl parathion (298-00-0)

SAFETY

Risk and Safety Statements

Symbol(GHS) 
GHS06,GHS08,GHS09
Signal word  Danger
Hazard statements  H300+H330-H311-H373-H410
Precautionary statements  P260-P273-P280-P302+P352+P312-P304+P340+P310-P314
Hazard Codes  T+;N,N,T+,Xn,F
Risk Statements  5-24-26/28-48/22-50/53-10-67-66-51/53-36-20/22-11-65-38
Safety Statements  28-36/37-45-60-61-26-62-16
RIDADR  UN 2052/2783/2811
OEB C
OEL TWA: 0.2 mg/m3 [skin]
WGK Germany  3
RTECS  TG0175000
HazardClass  6.1(a)
PackingGroup  II
HS Code  29201100
Toxicity LD50 in male, female rats (mg/kg): 14, 24 orally; 67, 67 dermally (Gaines)
NFPA 704
0
4 0

Parathion-methyl Chemical Properties,Uses,Production

Chemical Properties

Methyl parathion is a white to yellow-brown, crystalline solid with a garlic odor.It is slightly soluble in water and has a low vapor pressure (U.S. EPA, 2006b).

Uses

Parathion-methyl is an derivative of Parathion (P192220), an organophosphate insecticide used on cotton, rice and fruit trees.

Definition

ChEBI: Parathion-methyl is a C-nitro compound that is 4-nitrophenol substituted by a (dimethoxyphosphorothioyl)oxy group at position 4. It is a synthetic organic thiophosphate compound and organophosphate acetylcholinesterase inhibitor that is the methyl homolog of parathion and is used as a pesticide. It is characterized as a colorless to white or tan crystalline solid that is odorless or has a pungent garlic-like odor, and exposure occurs by inhalation, ingestion, or contact.

Application

Parathion-methyl is a restricted use organophosphate sold under a number of trade names and formulations. First registered in 1954, it is used to control a variety of insect pests on food and feed crops. Methyl parathion is not used in residential settings due to its toxicity to humans, birds, and honey bees. The chemical is a restricted use pesticide with nearly 4 million pounds of active ingredient mainly used on cotton, corn, wheat, soybeans, and rice (U.S. EPA, 2006b).

General Description

Methyl parathion is a white crystalline solid dissolved in a liquid solvent carrier. The commercial product is a tan liquid (xylene solution) with a pungent odor. Parathion-methyl is slightly soluble to insoluble in water. Usually with the liquid solvent Parathion-methyl is a combustible liquid. Parathion-methyl is toxic by inhalation, ingestion and skin absorption. Parathion-methyl is used as an insecticide.

Air & Water Reactions

Insoluble in water.

Reactivity Profile

METHYL PARATHION is half decomposed in 8 days at 40°C. When a sample was heated in a small test tube Parathion-methyl decomposed in a few minutes, the residue exploded (Food Chem. 4(1):42. 1956).

Hazard

Explosion risk when heated. Toxicby skin absorption, inhalation, and ingestion;cholinesterase inhibitor. Use has been restricted.Questionable carcinogen.

Health Hazard

Parathion-methyl is extremely toxic; the probable oral lethal dose is 5-50 mg/kg, or between 7 drops and 1 teaspoonful for a 150-lb. person. Chronic toxicity does not appear to be a major consideration.

Fire Hazard

Poisonous gases are produced in fire and when heated. Decomposition may lead to sufficient internal pressure to cause the container to rupture violently. Avoid oxidizing materials. Unstable. High temperatures (120F) cause decomposition.

Agricultural Uses

Insecticide, Nematicide: A U.S. EPA restricted Use Pesticide (RUP). Severely Restricted for use in EU, as parathion-methyl. This material is used as an insecticide on over 50 crops, primarily cotton, but also on walnuts, corn, dried beans and almonds and on several ornamentals. It is no longer allowed to be used on crops consumed by children.

Trade name

A-GRO®[C]; AI3-17292®; ATOMIC®[C]; AZOFOS®; AZOPHOS; BAMA BRAND®[C]; BAY 11405®; BAY E-601®; BLADAN M®; CEKUMETHION®; CLEAN CROP®[C]; COTTON TOX DUST®[C]; DALF®; DECLARE®; DEVITHION®; DREXEL METHYL PARATHION 4E®[C]; DURHAM[C]; E 601®; EMMY®[C]; E-Z-FLO®[C]; FALL OUT®[C]; FMC NYNAMITE®[C]; FOLIDOC®; FOLIDOL-80®; FOLIDOL M®; FOLIDOL M-40®; FOSFERNO M 50®; GEARPHOS®; 8056HC®; KILEX PARATHION®; ME-PARATHION®; MEPTOX®; METACID 50®; METACIDE®; METAFOS®; METAPHOS®; METRON®; METHYL-E 605®; METRON®; NITROX®; NITROX® 80; OLEOVOFOTOX®; PARAPEST M-50®; PENNCAP M®; PENNCAP MLS®; QUINOPHOS®; SEIS-TRES 6-3®; SINAFID M-48®; SIXTY-THREE SPECIAL E. C. INSECTICIDE®; TEKWAISA®; THIOPHENIT®; THYLPAR M-50®; TOLL®; VERTAC METHYL PARATHION TECHNISCH 80%®; WOFATOX 50 EC®

Contact allergens

A case of sensitization to methyl-parathion was described in a female agricultural worker with multiple sensitization.

Safety Profile

Poison by inhalation, ingestion, skin contact, subcutaneous, intravenous, and intraperitoneal routes. Fatal poisoning can result from skin or eye contact after very brief exposure to concentrated solution. Experimental teratogenic and reproductive effects. Questionable carcinogen. Human mutation data reported. A cholinesterase inhibitor type of insecticide. When heated to decomposition it emits very toxic fumes of NOx, POx, and SOx.

Potential Exposure

A severely hazardous pesticide formulation. Alert: This material is used as an insecticide on over 50 crops, primarily cotton, and on several ornamentals

Carcinogenicity

When rats were given diets with 0, 0.5, 2.5, 12.5, and 50 ppm (0, 0.02, 0.1, 0.5, or 2 mg/kg/day (males); 0, 0.02, 0.1, 0.7, or 3 mg/kg/day (females) for 12 months, neuronal degeneration and plasma, erythrocyte, and brain cholinesterase inhibition occurred at 12.5 and 50 ppm .

Environmental Fate

Methyl parathion is mobile in soils and can leach into groundwater and enter surface water as runoff. The chemical breaks down though microbial degradation, aqueous photolysis, hydrolysis, and incorporation into soil organic matter; thus, it degrades rapidly in soil and water with a half-life <5 days. Photodegradation is rapid in aquatic environments with a half-life of 49 h. Bioconcentration is not expected to occur (U.S. EPA, 2006b).

Metabolic pathway

Parathion-methyl is a non-systemic insecticide and, where studied, metabolism parallels that of parathion and f enitrothion. The major routes of biotransformation involve desulfuration to the oxon analogue (paraoxon-methyl) and hydrolysis to give dimethyl phosphate, dimethyl phosphorothionate and 4-nitrophenol. Demethylation to give desmethylparathion- methyl and reduction of the nitro group also occurs. As with organophosphates, demethylation via glutathione-S-methyl transferases in the liver and some other tissues is an important mechanism in mammals. The major route of phase II metabolism involves conjugation of 4-nitrophenol followed by excretion.

Shipping

UN3017 Organophosphorus pesticides, liquid, toxic, flammable, flash point not ,23C, Hazard class: 6.1; Labels: 6.1-Poisonous materials, 3.-Flammable liquid. UN2783 Organophosphorus pesticides, solid, toxic, Hazard Class: 6.1; Labels: 6.1-Poisonous material. UN2811 Toxic solids, organic, n.o.s., Hazard Class: 6.1; Labels: 6.1- Poisonous materials, Technical Name Required

Incompatibilities

Incompatible with oxidizers, strong bases; heat. Mixtures with magnesium, or endrin may be violent or explosive. Slightly decomposed by acid solutions. Rapidly decomposed by alkalies. Explosive risk when heated above 50C. The liquid xylene solution decomposes violently @ 120C

Waste Disposal

Consult with environmental regulatory agencies for guidance on acceptable disposal practices. Generators of waste containing this contaminant (≥100 kg/mo) must conform to EPA regulations governing storage, transportation, treatment, and waste disposal. Incineration (816C, 0.5 second minimum for primary combustion; 1204C, 1.0 second for secondary combustion) with adequate scrubbing and ash disposal facilities. In accordance with 40CFR165, follow recommendations for the disposal of pesticides and pesticide containers. Must be disposed properly by following package label directions or by contacting your local or federal environmental control agency, or by contacting your regional EPA office

METACIDE(R) DALF(R) DANACAP(R) E601(R) DIMETHYL PARATHION FOLIDOL-M FOLIDOL-M(R) 8056HC a-gro Azofos Azophos BAY 11405 bay11405 baye-601 Bladan M bladan-m DALF demethylfenitrothion Devithion Dimethyl 4-nitrophenyl phosphorothionate Dimethyl p-Nitrophenyl phosphorothionate Dimethyl p-nitrophenyl thiophosphate dimethyl4-nitrophenylphosphorothionate dimethylp-nitrophenylmonothiophosphate dimethylp-nitrophenylphosphorothionate dimethyl-p-nitrophenylthionphosphate dimethylp-nitrophenylthiophosphate drexelmethylparathion4e e601 ENT 17292 ent17,292 epashaughnessycode:053501 Folidol M-40 folidol-80 folidolm-40 fosfernom50 Fulkil kilexparathion m40&80 ME605 me-parathion mepaton Meptox metacid Metacid 50 metacid50 metafos(pesticide) Metaphos Methyl-bladan Methyl-E 605 methyl-e605 methylfosferno methylniran Methylparathione Methylthiophos metilparation Metron (pesticide) o,o-Dimethyl o-(4-nitrophenyl) thiophosphate