PAN Pesticides Database - Chemicals

Metam-sodium - 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 Metam-sodium

Basic Identification Information About This Chemical
Chemical Name: Metam-sodium
CAS Number: 137-42-8 (Dihydrate. Used in EPA Cancer list.)
U.S. EPA PC Code: 039003
CA DPR Chem Code: 616
Molecular Weight: 129.17
Molecular Structure:
Use Type: Algaecide , Fumigant , Fungicide , Herbicide , Microbiocide , Nematicide
Chem Class: Dithiocarbamate-MITC
View Related Chemicals
Additional Resources About This Chemical Class and Use Type
Historical Use of this Chemical
Top five crops and sites for this pesticide in California
Carrots   Tomatoes for Processing   Potatoes   Strawberries   Bell Peppers  
View All Crops and Sites
Other Names for this Chemical
About Chemical Synonyms
(US EPA PC Code ) , 039003 (US EPA PC Code Text ) , 137-42-8 (CAS number) , 137428 , 137428 (CAS number without hyphens) , 616 (CA DPR Chem Code) ) , 6734-80-1 (CAS number) , 6734801 (CAS number without hyphens) , A7 Vapam , A7Vapam , Basamid-Fluid , C2H4NNaS2 , Carbam, sodium salt , Carbamic acid, N-methyldithio-, monosodium salt , Carbamodithioic acid, methyl-, monosodium salt , Karbation , Maposol , Metam , Metam sodium , Metam sodium, dihydrate , Metam sodium, dihydrate (CAS 137-42-8) , Metam, sodium , Metam-fluid BASF , Metam-sodium , METAM-SODIUM (CA DPR Chem Code Text ) , Metam-s?dico , Metam-s?dico  , Metame-s?dio , Metamsodium , metham sodium , Metham sodium (Sodium methyldithiocarbamate) , Metham-sodium , Methylcarbamodithioic acid, Monosodium salt , Methyldithiocarbamic acid monosodium salt dihydrate , Methyldithiocarbamic acid, sodium salt , N 869 , N-869 , N-Methylaminodithioformic acid, sodium salt , N-Methylaminomethanethionothiolic acid, sodium salt , N-Methyldithiocarbamic acid, sodium salt , Sistan , SMDC , Sodium metam , Sodium methylcarbamodithioate , Sodium monomethyldithiocarbamate , Sodium N-methylaminodithioformate , Sodium N-methylaminomethanethionothiolate , Sodium N-methyldithiocarbamate , Solasan 500 , Vapam , Woodfume Vapam
Products Containing This Chemical
Current and historic U.S. registered products
View U.S. Products All Products Currently Registered Products

Signs and Symptoms of Metam-sodium 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.

Metam-sodium is a Methyl Isothiocyanate (MITC)-generating compound.

Report a Poisoning

Symptoms of Poisoning with Methyl Isothiocyanate (MITC)-generating Compounds
Find Products Containing this Chemical

- Headache, dizziness
- Irritation of eyes, nose and throat
- Nausea, diarrhea
- Shortness of breath, chest tightness
- Symptoms delayed a week or more may include: weakness, diarrhea, cough, and rash

Source for Group Symptoms: Kreutzer, R. (1992). Acute health effects of the Cantara Metam-Sodium spill: An epidemiologic assessment, Environmental Health Investigations Branch, California Department of Health Services.

Treatment for Methyl Isothiocyanate (MITC)-generating Poisoning

See: Recognition and Management of Pesticide Poisoning, 5th edition, U.S. EPA, Chapter 15, page 141.


Toxicity Information for Metam-sodium

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

Summary Toxicity Information

PAN Bad Actor
Carcinogen Cholinesterase
Water Contaminant
Developmental or
Reproductive Toxin
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.

Detailed Toxicity Information

Acute Toxicity 2
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
II, Moderately Hazardous
Not Listed
Not Available
Highly Toxic
No NTP Studies

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

Water Pollution Potential and Criteria for Metam-sodium

Water Pollution Potential

PAN Ground Water Contaminant Rating 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)

Sorry, no water quality standards or criteria have been established for this chemical by the U.S. or Canadian governments; however, there may be criteria established for related chemicals.


Regulatory Information for Metam-sodium

International Regulatory Status

UNEP Persistent Organic Pollutant (POP)
UNEP Prior Informed Consent Chemical (PIC)
WHO Obsolete Pesticide
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
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

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Ecotoxicity for Metam-sodium

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
Crustaceans Mortality
Fish Behavior, Development, Enzyme(s), Genetics, Mortality, Physiology
Phytoplankton Cell(s), Population
Zooplankton Intoxication, Mortality
Zooplankton Intoxication
~ Un-Assigned Mortality
View All Aquatic Ecotoxicity Studies and References
Summary of Acute Toxicity for Organism Group
Organism Group Average Acute Toxicity Acute Toxicity Range
Crustaceans Very Highly Toxic Very Highly Toxic
Fish Highly Toxic Highly Toxic
Zooplankton Highly Toxic Highly Toxic
~ Un-Assigned Moderately Toxic Moderate to High Toxicity
View All Acute Summaries

Terrestrial Ecotoxicity

Summary of Acute Toxicity for Organism Group
Organism Group Average Acute Toxicity Acute Toxicity Range
HoneybeesSlightly ToxicSlightly 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 Metam-sodium

CAS Number Relation Reason Chemical Name Chem Detail Symptoms California Use Chem Use Type U.S. EPA Reg PAN Bad Actor
6734-80-1, 137-42-8 Parent P Metam-sodium View View View Fumigant, Herbicide, Fungicide, Microbiocide, Algaecide Yes Yes
144-54-7 Related 1 Metam acid View View View Fumigant No Yes
39680-90-5 Related 1 Metam ammonium View View View Fumigant No Not Listed
137-41-7 Related 1 Metam potassium View View View Fumigant, Fungicide, Microbiocide, Algaecide, Nematicide Yes Yes
624-83-9 Related 5a Methyl isocyanate View View View Breakdown product No Yes
556-61-6 Related 5a Methyl isothiocyanate View View View Fumigant, Insecticide, Herbicide, Nematicide, Breakdown product Yes Yes
21160-95-2 Related 1 Methylammonium N-methyldithiocarbamate View View View Fumigant, Herbicide, Nematicide, Fungicide 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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