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Methyl parathion - Identification, toxicity, use, water pollution potential, ecological toxicity and regulatory information

Note: See Working with the Information on this Page section below for important notes about this data.

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Chemical ID
 Identifying information, including synonyms, ID numbers, use type, chemical classification, a link to a list of all products containing this chemical and a list of the top crops this pesticide is used on in California.
Poisoning Symptoms
 Signs and symptoms of poisoning, first aid, and links to treatment information for this chemical.
Toxicity
 Link to information on toxicity to humans, including carcinogenicity, reproductive and developmental toxicity, neurotoxicity, and acute toxicity.
Regulatory
 Links to world-wide registration status as well as regulatory information for the U.S. and California.
Water
 Water quality standards and physical properties affecting water contamination potential.
Ecotoxicity
 Toxicity to aquatic organisms.
Related Chems
 List of chemicals in the same family, including breakdown products, salts, esters, isomers, and other derivatives.
 

Chemical Identification and Use for Methyl parathion
Basic Identification Information About This Chemical
Chemical Name: Methyl parathion
CAS Number: 298-00-0
U.S. EPA PC Code: 053501
CA DPR Chem Code: 394
Molecular Weight: 263.2
Molecular Structure:
Use Type: Insecticide , Nematicide
Chem Class: Organophosphorus
View Related Chemicals
 
Additional Resources About This Chemical Class and Use Type

See the Global Pesticide Resources page for many additional links.
Historical Use of this Chemical
Top five crops and sites for this pesticide in California
Walnuts   Potatoes   Onions   Leaf Lettuce   Dried Beans  
View All Crops and Sites
 
Other Names for this Chemical
About Chemical Synonyms
00394 (CA DPR Chem Code Text) , 00394 (CA DPR Chem Code) , 053501 (US EPA PC Code Text) , 057 (PDP Code) , 298-00-0 (CAS number) , 298000 , 298000 (CAS number without hyphens) , 394 (CA DPR Chem Code) , 394 (CA DPR Chem Code) , 53501 (US EPA PC Code) , Folidol M , Metacide , Metafos , Methyl parathion , Methyl Parathion(Penncap-M) , Methyl-parathion , Methyl-parathion (emulsifiable concentrates (EC) with 19.5%, 40%, 50%, 60% active ingredient and dusts containing 1.5%, 2% and 3 , Methylparathion , Metilparation , Metron , O,O-Dimethyl O-p-nitrophenyl phosphorothioate , O,O-Dimethyl O-p-nitrophenyl thiophosphate , Parathion methyl , Parathion methyl , Parathion-methyl , Parationa-met?lica , Penncap M , Phosphorothioic acid, O,O-dimethyl O-4-nitrophenyl ester
 
Products Containing This Chemical
Current and historic U.S. registered products
View U.S. Products All Products Currently Registered Products
 

Signs and Symptoms of Methyl parathion Poisoning

NOTE! There may be other diseases and chemicals that have similar symptoms.

If you have a poisoning emergency in the United States call 1-800-222-1222.
If the victim has collapsed or is unconscious, call 911.

Methyl parathion is a Organophosphorus compound.

Report a Poisoning
Symptoms of Poisoning with Organophosphorus Compounds
Find Products Containing this Chemical

- Excessive salivation, sweating, rhinorrhea and tearing.
- Muscle twitching, weakness, tremor, incoordination.
- Headache, dizziness, nausea, vomiting, abdominal cramps, diarrhea.
- Respiratory depression, tightness in chest, wheezing, productive cough, fluid in lungs.
- Pin-point pupils, sometimes with blurred or dark vision.
- Severe cases: seizures, incontinence, respiratory depression, loss of consciousness.
- Cholinesterase inhibition.

Source for Group Symptoms: Recognition and Management of Pesticide Poisoning, 5th edition, U.S. EPA, Chapter 4.
Treatment for Organophosphorus Poisoning

See: Recognition and Management of Pesticide Poisoning, 5th edition, U.S. EPA, Chapter 4, page 40.

 
Symptoms of Methyl parathion Exposure from the International Chemical Safety Cards (ICSC)

Report a Poisoning
View full ICSC Cards: English   Español   Française   Chinese   Dutch   Finnish   German   Hungarian   Japanese   Swahili   Thai   Urdu  
NOTE! PREVENT DISPERSION OF DUST! STRICT HYGIENE! AVOID EXPOSURE OF ADOLESCENTS AND CHILDREN!
 General First Aid: IN ALL CASES CONSULT A DOCTOR!

Route of Exposure

Symptoms

First Aid
Inhalation Convulsions. Dizziness. Sweating. Laboured breathing. Nausea. Unconsciousness. Vomiting. Pupillary constriction muscle cramp excessive salivation. Symptoms may be delayed (see Notes). Fresh air rest. Refer for medical attention.
Skin MAY BE ABSORBED! Muscle twitching. (See Inhalation). Remove contaminated clothes. Rinse and then wash skin with water and soap. Refer for medical attention.
Eyes Redness. Pain. Blurred vision. Pupillary constriction. First rinse with plenty of water for several minutes (remove contact lenses if easily possible) then take to a doctor.
Ingestion Abdominal cramps. Diarrhoea. Laboured breathing. Nausea. Unconsciousness. Vomiting. Pupillary constriction. Muscle cramps. Induce vomiting (ONLY IN CONSCIOUS PERSONS!). Rest. Refer for medical attention.
Notes for ICSC Information
Depending on the degree of exposure periodic medical examination is indicated. The symptoms of acute intoxication do not become manifest until some hours have passed. 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. Metacide Bladan-M Folidol-M Nitrox-80 are trade names.
 

Toxicity Information for Methyl parathion

  Note: Information for many chemicals is incomplete and may not be fully representative of effects on humans. Why?

Summary Toxicity Information

PAN Bad Actor
Chemical 1 		Acute
Toxicity 2 		Carcinogen Cholinesterase
Inhibitor 		Ground
Water Contaminant 		Developmental or
Reproductive Toxin 		Endocrine
Disruptor
Unclassifiable
Potential
Suspected
 
Indicates high toxicity in the given toxicological category. Indicates no available weight-of-the-evidence summary assessment. For additional information on toxicity from scientific journals or registration documents, see the "Additional Resources for Toxicity " section of the chemical detail page.
1. PAN Bad Actors are chemicals that are one or more of the following: highly acutely toxic, cholinesterase inhibitor, known/probable carcinogen, known groundwater pollutant or known reproductive or developmental toxicant. NOTE! Because there are no authoritative lists of Endocrine Disrupting (ED) chemicals, EDs are not yet considered PAN Bad Actor chemicals.
2. The acute toxicity reported on this page is of the pure chemical ingredient only and may not reflect the acute toxicity of individual pesticide products. To view acute toxicity of individual products, click on 'View Products' link in the 'Chemical Identification' section above.

Additional Resources about the Toxicity of this Chemical

See the Global Pesticide Resources page for many additional links.

Detailed Toxicity Information
Acute Toxicity 2
 Methyl parathion
WHO Acute Hazard
TRI Acute Hazard
Material Safety Data Sheets
Acute rating from U.S. EPA product label
U.S. NTP Acute Toxicity Studies
      View Studies
Cholinesterase Inhibitor		 Ia, Extremely Hazardous
Not Listed
Not Available
No Consensus Value
Slightly to Highly Toxic

Yes
2. The acute toxicity reported on this page is of the pure chemical ingredient only and may not reflect the acute toxicity of individual pesticide products. To view acute toxicity of individual products, click on 'View Products' link in the 'Chemical Identification' section above.
 
Cancer Information
 Methyl parathion
IARC Carcinogens
U.S. NTP Carcinogens
California Prop 65 Known Carcinogens
U.S. EPA Carcinogens
TRI Carcinogen		 3, Unclassifiable
Not Listed
Not Listed
Not Likely
Not Listed
 
Endocrine Disruption
 Methyl parathion
Illinois EPA list
Keith list
Colborn list
Benbrook list
Danish Inert list
EU list		 Probable
Not Listed
Not Listed
Yes
Not listed
Yes
 
Reproductive and Developmental Toxicity
 Methyl parathion
CA Prop 65 Developmental Toxin
U.S. TRI Developmental Toxin
CA Prop 65 Female Reproductive Toxin
CA Prop 65 Male Reproductive Toxin
U.S. TRI Reproductive Toxin 		Not Listed
Not Listed
Not Listed
Not Listed
Not Listed
 
Chemicals of Special Concern
 Methyl parathion
PAN Bad Actors
PAN Dirty Dozen list		 Yes
Yes
 

Water Pollution Potential and Criteria for Methyl parathion

Water Pollution Potential

PAN Ground Water Contaminant Rating Potential
 
Physical Property Data Related to Water Contamination Potential
Water Solubility (Avg, mg/L)
Adsorption Coefficient (Koc)
Hydrolysis Half-life (Avg, Days)
Aerobic Soil Half-life (Avg, Days)
Anaerobic Soil Half-life (Avg, Days) 		70.0
476.0
45.0
12.0
1.00 		 
 

Water Standards and Criteria
U.S. National Drinking Water Standards and Health Criteria
 µg/L unless noted  
Maximum Contaminant Level (MCL) 0  
Maximum Contaminant Level Goal (MCLG)  
One Day Exposure Health Advisory Level 300.0  
Ten Day Exposure Health Advisory Level 300.0  
Lifetime Exposure Health Advisory Level 1.00  
Reference Dose 0.20 (µg/kg/day)  
U.S. Drinking Water Equivalent Level 7.00  
Concentration with Lifetime Cancer Risk of 1 in 10,000  
WHO Water Quality Criteria
Description Occurs in drinking-water at concentrations well below those at which toxic effects may occur
Notes Notes: n
 

Regulatory Information for Methyl parathion

International Regulatory Status
Registration in Selected Countries Registration in Selected Countries:
Methyl parathion
 
UNEP Persistent Organic Pollutant (POP)
UNEP Prior Informed Consent Chemical (PIC)
WHO Obsolete Pesticide
Yes
Not Listed
 

U.S. and California Regulatory Status
U.S. EPA Registered
U.S. EPA Hazardous Air Pollutant
U.S. EPA Minimum Risk Pesticide (25b list)

CA Registered
CA Groundwater Contaminant
CA Toxic Air Contaminant 		Yes
Not Listed
No

Yes
Potential
TAC
 

Maximum Tolerance and Residue Levels
Codex Alimentarius
   (UN FAO Maximum Residue Limits)
U.S. Maximum Tolerance Levels
European Union Maximum Residue Levels 		Go to web site

Go to web site
Go to web site
 

Ecotoxicity for Methyl parathion

Note! Information for many chemicals is incomplete and may not be fully representative of effects on the environment. Why? Click on underlined terms for definitions and additional information.

Aquatic Ecotoxicity
All Toxic Effects for Organism Group
Organism Group Effects Noted
Amphibians Behavior, Biochemistry, Development, Enzyme(s), Growth, Histology, Mortality, Physiology, Population
Annelida Biochemistry, Mortality, Population
AquaticPlants Accumulation, Biochemistry, Growth, Morphology, Mortality, Physiology, Population
Crustaceans Accumulation, Behavior, Biochemistry, Development, Enzyme(s), Feeding Behavior, Growth, Injury, Intoxication, Morphology, Mortality, Physiology, Population
Echinoderms Development
Fish Accumulation, Behavior, Biochemistry, Cell(s), Development, Enzyme(s), Feeding Behavior, Genetics, Growth, Histology, Hormone(s), Morphology, Mortality, No Effect Coded, Physiology, Reproduction
Insects Accumulation, Behavior, Growth, Histology, Intoxication, Mortality, Population
Molluscs Biochemistry, Development, Enzyme(s), Growth, Histology, Mortality, Physiology, Population
NematodesandFlatworms Growth, Mortality, Reproduction
Phytoplankton Accumulation, Biochemistry, Ecosystem Process, Enzyme(s), Growth, Histology, Mortality, Physiology, Population, Reproduction
Zooplankton Behavior, Biochemistry, Ecosystem Process, Enzyme(s), Feeding Behavior, Growth, Intoxication, Mortality, No Effect Coded, Population, Reproduction
~ Un-Assigned Behavior, Biochemistry, Cell(s), Enzyme(s), Growth, Histology, Morphology, Mortality, Population
View All Aquatic Ecotoxicity Studies and References
 
Summary of Acute Toxicity for Organism Group
Organism Group Average Acute Toxicity Acute Toxicity Range
Amphibians Moderately Toxic Slight to Moderate Toxicity
Annelida Moderately Toxic Moderate Toxicity
AquaticPlants Slightly Toxic Slight Toxicity
Crustaceans Very Highly Toxic High to Very High Toxicity
Fish Moderately Toxic Slight to Very High Toxicity
Insects Very Highly Toxic High to Very High Toxicity
Molluscs Slightly Toxic Slight to Very High Toxicity
NematodesandFlatworms Moderately Toxic Moderate Toxicity
Zooplankton Moderately Toxic Slight to Very High Toxicity
~ Un-Assigned Very Highly Toxic Very Highly Toxic
View All Acute Summaries
 

Terrestrial Ecotoxicity
Summary of Acute Toxicity for Organism Group
Organism Group Average Acute Toxicity Acute Toxicity Range
HoneybeesHighly ToxicHighly Toxic
Note: Population-level effects on honeybees may occur even if a pesticide has low acute toxicity. For example, certain pesticides interfere with honeybee reproduction, ability to navigate, or temperature regulation, any of which can have an effect on long-term survival of honeybee colonies. The neonicotinoids, pyrethroids and keto-enol pesticides are some types of pesticides causing one or more of these effects.
Honeybee Chronic Toxicity

Sorry, no honeybee chronic toxicity data available for this chemical. Try related chemicals.

Related Chemicals for Methyl parathion
CAS Number Relation Reason Chemical Name Chem Detail Registration Symptoms California Use Chem Use Type U.S. EPA Reg PAN Bad Actor
298-00-0 Parent P Methyl parathion View View View View Insecticide, Nematicide Yes Yes
950-35-6 Related 5b Methyl paraoxon View View View View Breakdown product No Yes
Related 8 Methyl parathion, other related View View View View Insecticide, Nematicide No Yes
 
Working with the Information on this Page

Click on underlined terms for definitions or go to the Pesticide Tutorial overview page.

Any underlined term with a book icon has additional information.

* Data marked with an asterisk indicates that this chemical is not explicitly listed on the corresponding list. Instead, it belongs to a group of chemicals that IS designated on the list. For example, if an agency assigns a classification of reproductive toxicant to "mercury compounds", that classification is applied to all mercury compounds in the PAN Pesticide database, which are then marked with an asterisk.

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Citation: Kegley, S.E., Hill, B.R., Orme S., Choi A.H., PAN Pesticide Database, Pesticide Action Network, North America (San Francisco, CA, 2010), http:www.pesticideinfo.org.
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