298-00-0

Basic information

• Product Name: Parathion-methyl
• Synonyms: NITROX 80(R);NITRAN;O,O-DIMETHYL O-(4-NITROPHENYL)-PHOSPHOROTHIOATE;O,O-DIMETHYL-O-P-NITROPHENYL PHOSPHOROTHIOATE(R);O,O-Dimethyl O-(p-nitrophenyl) thionophosphate;PARASHOOT(R);PARATHION-METHYL;PARTON(R)
• CAS NO: 298-00-0
• Molecular Formula: C₈H₁₀NO₅PS
• Molecular Weight: 263.21
• EINECS: 206-050-1
• Product Categories: Agro-Chemicals;INSECTICIDE;META - METHEnvironmental Standards;2000/60/ECMore...Close...;AcaricidesMethod Specific;Alpha sort;Endocrine Disruptors (Draft)Pesticides&Metabolites;EPA;European Community: ISO and DIN;H-MAlphabetic;Insecticides;M;MetabolitesPesticides;Oeko-Tex Standard 100;OrganophorousMethod Specific;Pesticides;Pesticides&Metabolites;PesticidesMethod Specific;Endocrine Disruptors (Draft)Alphabetic
• Mol File: 298-00-0.mol

Chemical Properties

• Melting Point: 36°C
• Boiling Point: 143°C (1.0 mmHg)
• Flash Point: 46.1°C
• Appearance: /solid
• Density: 1.36
• Vapor Pressure: 2.25E-05mmHg at 25°C
• Refractive Index: nD25 1.5367
• Storage Temp.: APPROX 4°C
• Water Solubility: 0.005 g/100 mL
• Stability: Stable. Flammable.
• BRN: 8905814
• CAS DataBase Reference: Parathion-methyl(CAS DataBase Reference)
• NIST Chemistry Reference: Parathion-methyl(298-00-0)
• EPA Substance Registry System: Parathion-methyl(298-00-0)

Safety Data

• Hazard Codes: T+;N,N,T+,Xn,F
• 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
• WGK Germany: 3
• RTECS: TG0175000
• HazardClass: 6.1(a)
• PackingGroup: II
• Hazardous Substances Data: 298-00-0(Hazardous Substances Data)

Usage

Uses

Used in Agricultural Industry:
Parathion-methyl is used as an insecticide and acaricide for controlling boll weevils and many biting or sucking insect pests of agricultural crops. It is effective through contact, stomach, and respiratory action. The chemical is a restricted use pesticide, mainly used on cotton, rice, and fruit trees, as well as other crops such as corn, wheat, soybeans, and almonds.
Parathion-methyl is available in various formulations, including dust, emulsifiable concentrate, ULV liquid, microencapsules, and wettable powder. It is a derivative of Parathion (P192220) and belongs to a class of insecticides known as organophosphates. These chemicals act by interfering with the activities of cholinesterase, an enzyme essential for the proper functioning of the nervous systems of humans, animals, and insects.

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.

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

Degradation

Parathion-methyl (1) is hydrolysed under acidic and alkaline conditions. The rate is five times faster than for parathion. Upon heating it isomerises via a thonwthiolo rearrangement to yield S-methylparahon-methyl (2) (PM). The hydrolysis of the active anticholinesterase oxon analogue (paraoxon-methyl) (3) is much faster than that of parathion-methyl. The products of parathion-methyl hydrolysis were 4-nitrophenol (4) and dimethyl phosphorothioate (5) (Thuma et al., 1983). Hydrolysis is much more rapid in alkaline than in acidic or neutral media. Photodegradation in natural sunlight led to the formation of O,O,S-trimethyl phosphorothioate (6) and trimethyl phosphate (7) (Chukwudebe et al., 1989). Zweiner et al. (1994) examined the photolysis of parathion-methyl in aqueous solution after irradiation by unfiltered UV light. The major metabolites, which were detected by GC-MS, were paraoxon-methyl (3) and 4-nitrophenol (4). These conversions are shown in Scheme 1.

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

InChI:InChI=1/C8H10NO5PS/c1-13-15(12,14-2)16-8-5-3-7(4-6-8)9(10)11/h3-6H,1-2H3

Upstream product

• 5930-72-3 dimethyl thiophosphite 
• 100-02-7 4-nitro-phenol 
• 2524-03-0 dimethyl chlorothiophosphate 
• 824-78-2 4-nitrophenol sodium salt 
• 28341-54-0 4-(4-nitrophenoxy)butanoic acid 
• 124-41-4 sodium methylate 

Downstream Products

• 135513-16-5 (S)-O,S-dimethyl O-(p-nitrophenyl)phosphorothiolate 
• 135513-15-4 (R)-O,S-dimethyl O-(p-nitrophenyl)phosphorothiolate 
• 109818-20-4 thiophosphoric acid S-methyl ester-O-(4-nitro-phenyl ester); trimethyl sulfonium-salt 
• 100-02-7 4-nitro-phenol 
• 1111-99-5 monomethyl thiophosphate 
• 123-30-8 4-amino-phenol 
• 44515-17-5 O,O-dimethyl phosphorothioate 
• 14609-74-6 p-nitrophenolate 
• 152-20-5 O,O,S-trimethyl phosphorothioate 
• 950-35-6 methyl paraoxon 
• 123-31-9 hydroquinone 
• 507-09-5 tiolacetic acid 
• 131-11-3 phthalic acid dimethyl ester 
• 472-41-3 4-p-hydroxyphenyl-2,2,4-trimethylchroman 

Relevant articles and documents

LiI/TBHP Mediated Oxidative Cross-Coupling of P(O)–H Compounds with Phenols and Various Nucleophiles: Direct Access to the Synthesis of Organophosphates

An efficient and mild method for the direct phosphorylation of phenols, alcohols, and amines with P(O)–H has been reported by LiI/TBHP mediated oxidative cross-coupling reaction. Moreover, this protocol extended to β-keto esters for the synthesis of enol phosphates using H-phosphonates. Notably, this developed method applied for the synthesis of organopesticides such as paraoxon, cyanophos, and methyl parathion. The key features of this protocol are mild conditions, short reaction time, good functional group tolerance, and broad substrate scope.

A METHOD FOR NEUTRALIZATION OF TOXIN AGENTS, PESTICIDES AND THEIR HYDROLYSATES, AND A REAGENT FOR IT

This invention relates to the technology of ecotoxicants treatment, mainly chemical weapons (toxin agents), pesticides, hydrolysis products of toxin agents and pesticides. The method provides destruction of toxin agents, pesticides or their hydrolysates with further biodegradation of received products and can used for a wide range of ecotoxicants. The method can also be applied for cleaning of soils and objects contaminated with toxin agents and pesticides. In the claimed embodiments of the method, an amino acid reagent is used as a reagent for chemical neutralization of toxin agents, pesticides or their hydrolysates. Neutralization of ecotoxicants toxicity is carried out by application of a reagent containing an amino acid or a mixture of amino acids or peptides or derivatives of amino acids and peptides or their mixture in aqueous or aqueous organic medium. As the reagent hydrolysis products of protein containing factory waste can also be applied.

Comparisons of phosphorothioate with phosphate transfer reactions for a monoester, diester, and triester: Isotope effect studies

Phosphorothioate esters are sometimes used as surrogates for phosphate ester substrates in studies of enzymatic phosphoryl transfer reactions. To gain better understanding of the comparative inherent chemistry of the two types of esters, we have measured equilibrium and kinetic isotope effects for several phosphorothioate esters of p-nitrophenol (pNPPT) and compared the results with data from phosphate esters. The primary 18O isotope effect at the phenolic group (18kbridge), the secondary nitrogen-15 isotope effect (15k) in the nitro group, and (for the monoester and diester) the secondary oxygen-18 isotope effect (18knonbridge) in the phosphoryl oxygens were measured. The equilibrium isotope effect (EIE) 18knonbridge for the deprotonation of the monoanion of pNPPT is 1.015 ± 0.002, very similar to values previously reported for phosphate monoesters. The EIEs for complexation of Zn2+ and Cd2+ with the dianion pNPPT2- were both unity. The mechanism of the aqueous hydrolysis of the monoanion and dianion of pNPPT, the diester ethyl pNPPT, and the triester dimethyl pNPPT was probed using heavy atom kinetic isotope effects. The results were compared with the data reported for analogous phosphate monoester, diester, and triester reactions. The results suggest that leaving group bond fission in the transition state of reactions of the monoester pNPPT is more advanced than for its phosphate counterpart pNPP, while alkaline hydrolysis of the phosphorothioate diester and triester exhibits somewhat less advanced bond fission than that of their phosphate ester counterparts.

Selective Sulfur Oxygenation in Phosphoroamidate, Thionophosphate, and Thiophosphate Agrochemicals by Perfluoro-cis-2,3-dialkyloxaziridine

Several organophsophorus agrochemicals 2a-g with thioether, phosphoramidic, phosphorothioic, and phosphorothionic functions were reacted with perfluoro-cis-2-n-butyl-3-n-propyloxaziridine 1.The selective oxygenation of sulfide function to give sulfoxide derivatives 3a-g occured in high yields without overoxidation to sulfone products.Sulfoxides 3a-e were further oxidized under mild conditions to the corresponding sulfones 4a-e.All the products are themselves of interest as analytical environmental standards and their preparation is described in detail.

Oil-in-water emulsions and a process for their preparation and their use

Oil-in-water emulsions (microemulsions) containing 0.01-80% by weight of at least one agrochemical active substance of low water-solubility, one active substance for combating pests in the domestic and hygiene sector and/or one pharmacologically active substance, 1% to 30% by weight of an emulsifier mixture of non, ionic and anionic compounds and at least one alkylarylsulfonic acid salt, as defined in the description, as well as water and, if appropriate, 1% to 30% by weight of at least one solvent of low water-miscibility and/or one solubilizer, and if appropriate 0.05% to 15% by weight of additives, the sum of the components in each case being 100% by weight, a process for the preparation of these aqueous microemulsions and their use.

Macrocyclic plant acaricides

Compounds of the formula I STR1 in which either R is methyl and there is a double bond in the 9,10-position, or in which R is hydrogen and there is a single bond in the 9,10-position, are highly active against Acarina which damage plants.

Biocidal macroemulsions containing polyvinyl alcohol

The present invention relates to new macroemulsions which contain 0.001 to 60 percent by weight of at least one active compound from the class comprising the phosphates and/or carbamates, 0 to 50 percent by weight of aromatic diluents, 0.001 to 20 percent by weight of polyvinyl alcohol having a mean molecular weight of between 5,000 and 150,000 and a content of acetate groups of between 2 and 30 mol %, and/or 0.001 to 20 percent by weight of a nonlphenol/propylene oxide/ethylene oxide adduct of the formula STR1 in which X represents integers from 10 to 50 and Y represents integers from 15 to 65, and/or 0.001 to 20 percent by weight of ethylene oxide/propylene oxide/ethylene oxide block copolymers having a mean molecular weight of between 2,000 and 8,000 and HLB values of between 8 and 30, and water and, if appropriate, additives, and in which the oil phase is dispersed in the aqueous phase in the form of droplets having a mean particle diameter of 0.1 to 3.0 μm.

Oil-in-water emulsions, and their use

Novel oil-in-water emulsions, which contain (a) 0.1 to 80% by weight of at least one sparingly water-soluble active compound (as herein defined) selected from agrochemical active compounds, active compounds for combating pests in the domestic field and hygiene field and/or pharmacologically active compounds, (b) 1 to 20% by weight of at least one alkylaryl polyglycol ether of the general formula STR1 wherein R1 represents a hydrogen atom or an alkyl group having 1 to 16 carbon atoms, R3 represents a hydrogen atom or a methyl group, m is 1, 2 or 3, and n is an integer from 10 to 50, if appropriate in a mixture with an alkylarylsulphonic acid salt of the general formula STR2 wherein R3 represents an alkyl group having 8 to 35 carbon atoms and Me≈ represents an alkali metal cation, an equivalent of an alkaline earth metal cation or a cation of the general formula STR3 wherein R', R", R'" and RIV independently of one another represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or a hydroxyalkyl group having 1 to 4 carbon atoms, (c) water, (d) if necessary, 1 to 30% by weight of at least one poorly water-miscible organic solvent and/or a solubilizer, and (e) if appropriate 0.05 to 15% by weight of one or more additives, the sum of the components being 100% by weight in each case, a process for the preparation of these emulsions and their use in the field appropriate to the active compound.