| Identification | More | [Name]
Parathion-methyl | [CAS]
298-00-0 | [Synonyms]
CEKUMETHION
DALF(R)
DANACAP(R)
DIMETHYL PARATHION
E601(R)
FOLIDOL-M
FOLIDOL-M(R)
METACIDE
METACIDE(R)
METHYL PARATHION
METRON(R)
MPT(R)
NITRAN
NITROX 80(R)
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
PARIDOL(R) | [EINECS(EC#)]
206-050-1 | [Molecular Formula]
C8H10NO5PS | [MDL Number]
MFCD00041813 | [Molecular Weight]
263.21 | [MOL File]
298-00-0.mol |
| Chemical Properties | Back Directory | [Appearance]
Methyl parathion is a white to yellow-brown,
crystalline solid with a garlic odor. | [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 | [Fp ]
46.1°C | [storage temp. ]
APPROX 4°C
| [solubility ]
Chloroform: Slightly Soluble,Methanol: Slightly Soluble | [form ]
solid | [Stability:]
Stable. Flammable. | [Water Solubility ]
0.005 g/100 mL | [BRN ]
8905814 | [Contact allergens]
A case of sensitization to
methyl-parathion was described in a female agricultural
worker with multiple sensitization. | [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]
298-00-0(EPA Substance) |
| Hazard Information | Back Directory | [Chemical Properties]
white crystalline powder | [Uses]
Parathion-methyl is an derivative of Parathion (P192220), an organophosphate insecticide used on cotton, rice and fruit trees. | [Definition]
ChEBI: A C-nitro compound that is 4-nitrophenol substituted by a (dimethoxyphosphorothioyl)oxy group at position 4. | [Uses]
Insecticide. | [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. METHYL PARATHION, [LIQUID] is slightly soluble to insoluble in water. Usually with the liquid solvent METHYL PARATHION, [LIQUID] is a combustible liquid. METHYL PARATHION, [LIQUID] is toxic by inhalation, ingestion and skin absorption. METHYL PARATHION, [LIQUID] is used as an insecticide. | [Reactivity Profile]
METHYL PARATHION is half decomposed in 8 days at 40°C. When a sample was heated in a small test tube METHYL PARATHION, [LIQUID] decomposed in a few minutes, the residue exploded (Food Chem. 4(1):42. 1956). | [Air & Water Reactions]
Insoluble in water. | [Hazard]
Explosion risk when heated. Toxicby skin absorption, inhalation, and ingestion;cholinesterase inhibitor. Use has been restricted.Questionable carcinogen. | [Health Hazard]
This material 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. | [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 | [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. | [First aid]
If this chemical gets into the eyes, remove any
contact lenses at once and irrigate immediately for at least
15 minutes, occasionally lifting upper and lower lids. Seek
medical attention immediately. If this chemical contacts the
skin, remove contaminated clothing and wash immediately
with soap and water. Speed in removing material from skin
is of extreme importance. Shampoo hair promptly if contaminated. Seek medical attention immediately. If this
chemical has been inhaled, remove from exposure, begin
rescue breathing (using universal precautions, including
resuscitation mask) if breathing has stopped and CPR if
heart action has stopped. Transfer promptly to a medical
facility. When this chemical has been swallowed, get medical attention. Give large quantities of water and induce
vomiting. Do not make an unconscious person vomit.
Effects of exposure may be delayed. Medical monitoring is
advised. | [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 | [Description]
A case of sensitization to parathion methyl was
described in a female agricultural worker with multiple
sensitization. | [Description]
Methyl parathion is an organophosphate insecticide.1 It is converted into an oxon-containing metabolite in vivo, similar to other organophosphate pesticides, that inhibits acetylcholinesterase. Methyl parathion is lethal to lab strains and field isolates of tobacco budworm larvae (LD50s = 7 and 81.8-128.3 μg/g, respectively).2 It reduces the number of stink bugs (C. sayi) caught per 100 net sweeps when applied to alfalfa fields at a concentration of 0.4 pounds per acre.3 Methyl parathion increases sister chromatid exchange (SCE) in a concentration-dependent manner and induces cell cycle arrest at the M1 phase in V79 cells at a concentration of 40 μg/ml.4 It is toxic to rats (LD50 = 14 mg/kg).1 | [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 | [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). | [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® | [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. | [storage]
Store at -20°C | [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. |
| Safety Data | Back Directory | [Hazard Codes ]
T+;N,N,T+,Xn,F | [Risk Statements ]
R5:Heating may cause an explosion.
R24:Toxic in contact with skin.
R26/28:Very Toxic by inhalation and if swallowed .
R48/22:Harmful: danger of serious damage to health by prolonged exposure if swallowed .
R50/53:Very Toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment .
R10:Flammable.
R67:Vapors may cause drowsiness and dizziness.
R66:Repeated exposure may cause skin dryness or cracking.
R51/53:Toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment .
R36:Irritating to the eyes.
R20/22:Harmful by inhalation and if swallowed .
R11:Highly Flammable.
R65:Harmful: May cause lung damage if swallowed.
R38:Irritating to the skin. | [Safety Statements ]
S28:After contact with skin, wash immediately with plenty of ... (to be specified by the manufacturer) .
S36/37:Wear suitable protective clothing and gloves .
S45:In case of accident or if you feel unwell, seek medical advice immediately (show label where possible) .
S60:This material and/or its container must be disposed of as hazardous waste .
S61:Avoid release to the environment. Refer to special instructions safety data sheet .
S26:In case of contact with eyes, rinse immediately with plenty of water and seek medical advice .
S62:If swallowed, do not induce vomiting: seek medical advice immediately and show this container or label . | [RIDADR ]
UN 2052/2783/2811 | [WGK Germany ]
3 | [RTECS ]
TG0175000 | [HazardClass ]
6.1(a) | [PackingGroup ]
II | [HS Code ]
29201100 | [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. | [Hazardous Substances Data]
298-00-0(Hazardous Substances Data) | [Toxicity]
LD50 in male, female rats (mg/kg): 14, 24 orally; 67, 67 dermally (Gaines) |
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