PAN Pesticides Database - Chemicals

Methomyl - 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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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.
Signs and symptoms of poisoning, first aid, and links to treatment information for this chemical.
Link to information on toxicity to humans, including carcinogenicity, reproductive and developmental toxicity, neurotoxicity, and acute toxicity.
Links to world-wide registration status as well as regulatory information for the U.S. and California.
Water quality standards and physical properties affecting water contamination potential.
Toxicity to aquatic organisms.
List of chemicals in the same family, including breakdown products, salts, esters, isomers, and other derivatives.
 

Chemical Identification and Use for Methomyl

Basic Identification Information About This Chemical
Chemical Name: Methomyl
CAS Number: 16752-77-5
U.S. EPA PC Code: 090301
549400 (Old US EPA PC Code.)
CA DPR Chem Code: 383
Molecular Weight: 162.2
Molecular Structure:
Use Type: Breakdown product , Insecticide
Chem Class: N-Methyl Carbamate
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
Corn   Head Lettuce   Leaf Lettuce   Onions   Table and Raisin Grapes  
View All Crops and Sites
 
Other Names for this Chemical
About Chemical Synonyms
00383 (CA DPR Chem Code Text) , 00383 (CA DPR Chem Code) , 090301 (US EPA PC Code Text) , 159 (PDP Code) , 16752-77-5 (CAS number) , 16752775 , 16752775 (CAS number without hyphens) , 3-Thiobutan-2-one, O-(methylcarbamoyl)oxime , 383 (CA DPR Chem Code) , 383 (CA DPR Chem Code) , 549400 (Old US EPA PC Code) , 549400 (US EPA PC Code Text) , 549400 (US EPA PC Code) , 90301 (US EPA PC Code) , Acetimidic acid, N-((methylcarbamoyl)oxy)thio-, methyl ester , Acetimidic acid, thio-, N-((methylcarbamoyl)oxy)-, S-methyl ester , Carbamic acid, N-methyl-, compd. with (2-methylthio)acetaldoxime , DuPont 1179 , Ethanimidothioic acid, N-(((methylamino)carbonyl)oxy)-, methyl ester (9CI) , IN 1179 , Insecticide 1179 , Lannate , Lanox 216 , Lanox 90 , Lurectron flybait (090301+103201) , Mesomile , Methomyl , Methomyl , Methomyl (ANSI) , Methyl O-(methylcarbamoyl)thiolacetohydroxamate , Metomil , Nu-Bait II , Nudrin , S-Methyl N-((methylcarbamoyl)oxy)thioacetimidate , S-Methyl-N ((Methylcarbamoyl)Oxy) Thioacetimidate , SD 14999 , Thiodicarb breakdown product , Use code no. 090301 , WL 18236
 
Products Containing This Chemical
Current and historic U.S. registered products
View U.S. Products All Products Currently Registered Products
 

Signs and Symptoms of Methomyl 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.

Methomyl is a high toxicity Carbamate compound.

Report a Poisoning

Symptoms of Poisoning with high toxicity Carbamate Compounds
Find Products Containing this Chemical

High Toxicity Carbamate Pesticides:
- Malaise, muscle weakness, dizziness, and sweating.
- Headache, salivation, nausea, vomiting, abdominal pain, and diarrhea.
- Miosis with blurred vision, incoordination, muscle twitching and slurred speech.
- In more severe cases: Central nervous system depression (coma, seizures and hypotonicity), hypertension and cardiorespiratory depression. Also dyspnea, bronchospasms and bronchorrhea with eventual pulmonary edema.

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

Treatment for high toxicity Carbamate Poisoning

See: Recognition and Management of Pesticide Poisoning, 5th edition, U.S. EPA, Chapter 5, page 50.

 
Symptoms of Methomyl 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 Dizziness. Headache. Sweating. Laboured breathing. Unconsciousness. Pupillary constriction muscle cramp excessive salivation. Fresh air rest. Half-upright position. Refer for medical attention. See Notes.
Skin MAY BE ABSORBED! (Further see Inhalation). Remove contaminated clothes. Rinse skin with plenty of water or shower. Refer for medical attention. (See Notes).
Eyes Redness. Blurred vision. First rinse with plenty of water for several minutes (remove contact lenses if easily possible) then take to a doctor.
Ingestion Abdominal cramps. Convulsions. Diarrhoea. Nausea. Vomiting. Weakness. Muscle twitching. (urther see Inhalation). Give a slurry of activated charcoal in water to drink. Induce vomiting (ONLY IN CONSCIOUS PERSONS!). Rest. Refer for medical attention. See Notes.
Notes for ICSC Information
Methomyl is a mixture of (Z)- and (E)-isomers. If the pesticide is present under the form of a formulation containing hydrocarbon solvents vomiting may not be induced. Specific treatment is necessary in case of poisoning with this substance; the appropriate means with instructions must be available. If the substance is formulated with solvent(s) also consult the card(s) (ICSC) of the solvent(s). Carrier solvents used in commercial formulations may change physical and toxicological properties. Do NOT take working clothes home. Du Pont 1179 Flytek Lannate Lanox Methavin Methomex Nudrin are trade names.
 

Toxicity Information for Methomyl

  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
Not Likely
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

This Chemical
Parent Chemical 
Acute Toxicity 2
Methomyl Thiodicarb
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
Ib, Highly Hazardous
Not Listed
Not Available
Highly Toxic
No NTP Studies

Yes
II, Moderately Hazardous
Not Listed
Not Available
Moderately Toxic
No NTP Studies

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
Methomyl Thiodicarb
IARC Carcinogens
U.S. NTP Carcinogens
California Prop 65 Known Carcinogens
U.S. EPA Carcinogens
TRI Carcinogen
Not Listed
Not Listed
Not Listed
E, Unlikely
Not Listed
Not Listed
Not Listed
Yes
B2, Probable
Not Listed
 
Endocrine Disruption
Methomyl Thiodicarb
Illinois EPA list
Keith list
Colborn list
Benbrook list
Danish Inert list
EU list
Suspected
Yes
Yes
Yes
Not listed
Yes
Not Listed
Not Listed
Not Listed
Not Listed
Not Listed
Not Listed
 
Reproductive and Developmental Toxicity
Methomyl Thiodicarb
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
Not Listed
Not Listed
Not Listed
Not Listed
Not Listed
 
Chemicals of Special Concern
Methomyl Thiodicarb
PAN Bad Actors
PAN Dirty Dozen list
Yes
Not Listed
Yes
Not Listed
 

Water Pollution Potential and Criteria for Methomyl

Water Pollution Potential

This Chemical
Parent Chemical
  Methomyl Thiodicarb
PAN Ground Water Contaminant Rating Potential Insufficient Data
 
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)
54,700
43.0
30.0
46.0
1.00
 
 

Water Standards and Criteria

This Chemical
Parent Chemical
U.S. National Drinking Water Standards and Health Criteria
g/L unless noted  
  Methomyl Thiodicarb
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 200.0  
Reference Dose 25.0 (g/kg/day)  
U.S. Drinking Water Equivalent Level 900.0  
Concentration with Lifetime Cancer Risk of 1 in 10,000  
WHO Water Quality Criteria
Description Unlikely to occur in drinking-water
Notes Notes: e
 

Regulatory Information for Methomyl

International Regulatory Status

This Chemical
Parent Chemical 
Registration in Selected Countries Registration in Selected Countries:
Methomyl

Registration for Selected Countries:
Thiodicarb

 
UNEP Persistent Organic Pollutant (POP)
UNEP Prior Informed Consent Chemical (PIC)
WHO Obsolete Pesticide
Not Listed
Not Listed
Not Listed
Not Listed
Not Listed
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
In Evaluation
Yes
Not Listed
No

Yes
Not Listed
Not Listed
 

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 Methomyl

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 Mortality
Crustaceans Development, Growth, Mortality
Fish Accumulation, Biochemistry, Enzyme(s), Growth, Mortality
Insects Behavior, Development, Intoxication, Mortality
Molluscs Intoxication, Mortality
Phytoplankton Biochemistry, Physiology, Population
Zooplankton Behavior, Enzyme(s), Feeding Behavior, Growth, Intoxication, Morphology, Mortality, Population, Reproduction
~ Un-Assigned Growth, Mortality, Reproduction
View All Aquatic Ecotoxicity Studies and References
 
Summary of Acute Toxicity for Organism Group
Organism Group Average Acute Toxicity Acute Toxicity Range
Amphibians Slightly Toxic Slight Toxicity
Crustaceans Highly Toxic Moderate to Very High Toxicity
Fish Moderately Toxic Moderate to Very High Toxicity
Insects Highly Toxic High to Very High Toxicity
Molluscs Slightly Toxic Slight to High Toxicity
Zooplankton Highly Toxic High to Very High Toxicity
View All Acute Summaries
 

Terrestrial Ecotoxicity

Summary of Acute Toxicity for Organism Group
Organism Group Average Acute Toxicity Acute Toxicity Range
HoneybeesHighly ToxicModerately to Highly 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 Methomyl

CAS Number Relation Reason Chemical Name Chem Detail Registration Symptoms California Use Chem Use Type U.S. EPA Reg PAN Bad Actor
59669-26-0 Parent P Thiodicarb View View View View Molluscicide, Insecticide Yes Yes
16752-77-5 Related 5a Methomyl View View View View Insecticide, Breakdown product Yes Yes
Related 5a Methomyl-oxime View View View View Breakdown product No Not Listed
 
Working with the Information on this Page

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

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* 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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