Metam-potassium	Last updated: 31/03/2021
(Not known by any other names)

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GENERAL INFORMATION

Description	A multi-action crop protection agent used as a pre-planting soil sterilant
Example pests controlled	Weed and disease suppression including control of annual bluegrass, chickweed, ragweed, nutgrass, morning glory, Sclerotina, club root and Rhizoctonia
Example applications	Vegetables; Fruit; Ornamentals; Fiber crops; Cover crops
Efficacy & activity	-
Availability status	Unknown
Introduction & key dates	1951, first reported

UK regulatory status

UK COPR regulatory status	Not approved
Date COPR inclusion expires	30/06/2025
UK LERAP status	None (may vary with mixtures)

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status	Approved
Dossier rapporteur/co-rapporteur	Belgium
Date EC 1107/2009 inclusion expires	30/06/2022
EU Candidate for substitution (CfS)	Yes - low ADI / ARfD / AOEL
Listed in EU database	Yes
Approved for use (✓) under EC 1107/2009 in the following EU Member States	ATAustria BEBelgium BGBulgaria CYCyprus CZCzech Republic DEGermany DKDenmark EEEstonia ELGreece   ✓ ✓ ✓         ✓ ESSpain FIFinland FRFrance HRCroatia HUHungary IEIreland ITItaly LTLithuania LULuxembourg ✓       ✓ ✓ ✓     LVLatvia MTMalta NLNetherlands PLPoland PTPortugal RORomania SESweden SISlovenia SKSlovakia   ✓ ✓ ✓ ✓ ✓

Also used in

Also used in	-

Chemical structure

Isomerism	-
Chemical formula	C₂H₄KNS₂
Canonical SMILES	CNC(=S)[S-].[K+]
Isomeric SMILES	No data
International Chemical Identifier key (InChIKey)	DQRQIQZHRCRSDB-UHFFFAOYSA-M
International Chemical Identifier (InChI)	InChI=1S/C2H5NS2.K/c1-3-2(4)5;/h1H3,(H2,3,4,5);/q;+1/p-1
2D structure diagram/image available?	Yes

General status

Pesticide type	Fungicide, Insecticide, Nematicide, Soil sterilent
Substance group	Carbamate
Minimum active substance purity	-
Known relevant impurities	-
Substance origin	Synthetic
Mode of action	Soil fumigant, binds to oxygen carrying molecules and prevents tissues from using oxygen.
CAS RN	137-41-7
EC number	205-29-25
CIPAC number	-
US EPA chemical code	039002
PubChem CID	23690432
Molecular mass	145.28
PIN (Preferred Identification Name)	potassium methylcarbamodithioate
IUPAC name	postassium methylcarbamodithioate
CAS name	potassium N-methylcarbamodithioate
Other status information	PAN bad actor; Marine pollutant
Relevant Environmental Water Quality Standards	-
Herbicide Resistance Classification (HRAC)	Not known
Herbicide Resistance Classification (WSSA)	Not known
Insecticide Resistance Classification (IRAC)	1A
Fungicide Resistance Classification (FRAC)	Not known
Examples of recorded resistance	-
Physical state	Colourless crystalline solid
Related substances & organisms	metam-sodium

Formulations

Property	Value
Example manufacturers & suppliers of products using this active now or historically	Tamifume Sectagon K-54
Example products using this active	Taminco N.V.
Formulation and application details	Usually supplied formulated for use as a fumigant

ENVIRONMENTAL FATE

Property		Value	Source; quality score; and other information	Interpretation
Solubility - In water at 20 °C (mg l⁻¹)		722000	Q3 Q = Miscellaneous internet resources 3 = Unverified data of known source	High
Solubility - In organic solvents at 20 °C (mg l⁻¹)		5000	Q3 Q = Miscellaneous internet resources 3 = Unverified data of known source Acetone	-
		5000	Q3 Q = Miscellaneous internet resources 3 = Unverified data of known source Ethanol	-
		5000	Q3 Q = Miscellaneous internet resources 3 = Unverified data of known source Xylene	-
Melting point (°C)		Decomposes before melting	Q3 Q = Miscellaneous internet resources 3 = Unverified data of known source	-
Boiling point (°C)		Decomposes before boiling	Q3 Q = Miscellaneous internet resources 3 = Unverified data of known source	-
Degradation point (°C)		-	-	-
Flashpoint (°C)		-	-	-
Octanol-water partition coefficient at pH 7, 20 °C	P	-	-	-
	Log P	-	-	-
Bulk density (g ml⁻¹)		-	-	-
Dissociation constant pKa) at 25 °C		-	-	-
		-
Vapour pressure at 20 °C (mPa)		-	-	-
Henry's law constant at 25 °C (Pa m³ mol⁻¹)		-	-	-
Maximum UV-vis absorption L mol⁻¹ cm⁻¹		-	-	-
Surface tension (mN m⁻¹)		-	-	-

Degradation

Property		Value	Source; quality score; and other information	Interpretation
General biodegradability		-
Soil degradation (days) (aerobic)	DT₅₀ (typical)	-	-	-
	DT₅₀ (lab at 20 °C)	-	-	-
	DT₅₀ (field)	-	-	-
	DT₉₀ (lab at 20 °C)	-	-	-
	DT₉₀ (field)	-	-	-
	DT₅₀ modelling endpoint	-	-	-
	Note	-
Dissipation rate RL₅₀ on plant matrix	Value	-	-	-
	Note	-
Dissipation rate RL₅₀ on and in plant matrix	Value	-	-	-
	Note	-
Aqueous photolysis DT₅₀ (days) at pH 7	Value	-	-	-
	Note	-
Aqueous hydrolysis DT₅₀ (days) at 20 °C and pH 7	Value	-	-	-
	Note	-
Water-sediment DT₅₀ (days)		-	-	-
Water phase only DT₅₀ (days)		-	-	-

Soil adsorption and mobility

Property		Value	Source; quality score; and other information	Interpretation
Linear	Kd	-	-	-
	Koc	-
	Notes and range	-
Freundlich	Kf	-	-	-
	Kfoc	-
	1/n	-
	Notes and range	-
pH sensitivity		-

Fate indices

Property		Value	Source; quality score; and other information	Interpretation
GUS leaching potential index		-	-	-
SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate	Value	Cannot be calculated	-	-
	Note	-
Potential for particle bound transport index		-	-	-
Potential for loss via drain flow		-	-	-

Key metabolites

Metabolite	Formation medium	Estimated maximum occurrence fraction	1107/2009 relevancy
methyl isothiocyanate (Ref: SN-32866)	Soil	0.829	Major fraction, Relevant

Other known metabolites

Metabolite name and reference	Aliases	Formation medium / Rate	Estimated maximum occurrence fraction	Metabolising enzymes
N,N’-dimethylthiourea	DMTU	Groundwater; Water/sediment	-	-
dimethylurea	DMU	Water/sediment	-	-
-	DMTD	Water/sediment	-	-

ECOTOXICOLOGY

Property		Value	Source; quality score; and other information	Interpretation
Bio-concentration factor	BCF (l kg⁻¹)	-	-	-
	CT₅₀ (days)	-		-
Mammals - Acute oral LD₅₀ (mg kg⁻¹)		630	Q3 Q = Miscellaneous internet resources 3 = Unverified data of known source Rabbit	Moderate
Mammals - Short term dietary NOEL	(mg kg⁻¹)	-	-	-
	(ppm diet)	-		-
Mammals - Chronic 21d NOAEL (mg kg⁻¹ bw d⁻¹)		-	-	-
Birds - Acute LD₅₀ (mg kg⁻¹)		> 211	A3 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications ) 3 = Unverified data of known source Colinus virginianus> as metam-sodium	Moderate
Birds - Short term dietary (LC₅₀/LD₅₀)		-	-	-
Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)		-	-	-
Fish - Acute 96 hour LC₅₀ (mg l⁻¹)		> 54.0	F4 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents (US EPA Databases Related to Pesticide Risk Assessment ) 4 = Verified data Oncorhynchus mykiss	Moderate
Fish - Chronic 21 day NOEC (mg l⁻¹)		-	-	-
Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)		> 4.6	P4 P = Other governments and regulators 4 = Verified data Daphnia magna	Moderate
Aquatic invertebrates - Chronic 21 day NOEC (mg l⁻¹)		-	-	-
Aquatic crustaceans - Acute 96 hour LC₅₀ (mg l⁻¹)		-	-	-
Sediment dwelling organisms - Acute 96 hour LC₅₀ (mg l⁻¹)		-	-	-
Sediment dwelling organisms - Chronic 28 day NOEC, static, water (mg l⁻¹)		-	-	-
Sediment dwelling organisms - Chronic 28 day NOEC, sediment (mg kg⁻¹)		-	-	-
Aquatic plants - Acute 7 day EC₅₀, biomass (mg l⁻¹)		-	-	-
Non-target plants		-	-	-
		-	-	-
Algae - Acute 72 hour EC₅₀, growth (mg l⁻¹)		-	-	-
Algae - Chronic 96 hour NOEC, growth (mg l⁻¹)		-	-	-
Honeybees (Apis spp.)	Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	-	-	-
	Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	-	-	-
	Unknown mode acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	-	-	-
Bumblebees (Bombus spp.)	Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	-	-	-
		-
	Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	-	-	-
		-
Mason bees (Osmia spp.)	Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	-	-	-
	Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	-	-	-
Other pollinators (1)	Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)	-	-	-
	Mode of exposure	-
Other pollinators (2)	Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)	-	-	-
	Mode of exposure	-
Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹)		> 400	A2 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications ) 2 = Unverified data of unknown source Eisenia foetida for metam-sodium	Moderate
Earthworms - Chronic NOEC, reproduction (mg kg⁻¹)		-	-	-
Other soil macro-organisms	Acute LC₅₀ (mg kg⁻¹)	-	-	-
	Chronic NOEC (mg kg⁻¹)	-	-	-
Other arthropod (1)	LR₅₀ g ha⁻¹	-	-	-
	% Effect	-	-	-
Other arthropod (2)	LR₅₀ g ha⁻¹	-	-	-
	% Effect	-	-	-
Soil micro-organisms		-	-	-
Mesocosm study data	NOEAEC mg l⁻¹	-	-	-
	NOEAEC mg l⁻¹	-	-	-

HUMAN HEALTH AND PROTECTION

General

Property		Value	Source; quality score; and other information	Interpretation
Threshold of Toxicological Concern (Cramer Class)		High (class III)	-	-
Mammals - Acute oral LD₅₀ (mg kg⁻¹)		630	Q3 Q = Miscellaneous internet resources 3 = Unverified data of known source Rabbit	Moderate
Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)		1000	Q3 Q = Miscellaneous internet resources 3 = Unverified data of known source Rat	-
Mammals - Inhalation LC₅₀ (mg l⁻¹)		-	-	-
Other Mammal toxicity endpoints		-	-	-
ADI - Acceptable Daily Intake (mg kg⁻¹ bw day⁻¹)		0.001	A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications ) 5 = Verified data used for regulatory purposes	-
ARfD - Acute Reference Dose (mg kg⁻¹ bw day⁻¹)		0.1	A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications ) 5 = Verified data used for regulatory purposes	-
AAOEL - Acute Acceptable Operator Exposure Level (mg kg⁻¹ bw day⁻¹)		-	-	-
AOEL - Acceptable Operator Exposure Level - Systemic (mg kg⁻¹ bw day⁻¹)		0.001	A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications ) 5 = Verified data used for regulatory purposes	-
Dermal penetration studies (%)		-	-	-
Dangerous Substances Directive 76/464		-	-	-
Exposure Routes	Public	-
	Occupational	-
MRLs	European	EU MRL pesticide database
	Notes	UK MRL levels for some commodities subject to change in late 2021
Drinking Water Standards		-	-	-
Drinking Water MAC (μg l⁻¹)		-	-	-

Health issues

Specific human health issues		Carcinogen Genotoxic Endocrine disruptor ?Possibly, status not identified A0 A = Chromosome aberration (EFSA database) 0 = No data ; B0 B = DNA damage/repair (EFSA database) 0 = No data ; C0 C = Gene mutation (EFSA database) 0 = No data ; D0 D = Genome mutation (EFSA database) 0 = No data ; E0 E = Unspecified genotoxicity type (miscellaneous data source) 0 = No data ?Possibly, status not identified Reproduction / development effects Acetyl cholinesterase inhibitor Neurotoxicant ✓Yes, known to cause a problem XNo, known not to cause a problem XNo, known not to cause a problem Respiratory tract irritant Skin irritant Skin sensitiser No data found ✓Yes, known to cause a problem ?Possibly, status not identified Eye irritant Phototoxicant   XNo, known not to cause a problem No data found
General human health issues		Highly toxic

Handling issues

Property	Value and interpretation
General	Corrosive May liberate toxic gas when in contact with acids Not explosive or oxidising IMDG Transport Code is usually 8
CLP classification 2013	Health: H302, H314, H317 Environment: H400, H410
EC Risk Classification	Reproduction risk category 3: R63 Xn - Harmful: R22, R43 H - Handling risks: R31, R34 N - Dangerous for the environment: R50, R53
EC Safety Classification	S1/2, S26, S36/37/39, S45, S60, S61
WHO Classification	II (Moderately hazardous)
UN Number	2771 for active, variable with product, usually 3082 or 3267
Waste disposal & packaging	Spilled product is a hazardous waste and disposal must be at an approved manner Packaging Group III (minor danger)

TRANSLATIONS

Language	Name
English	metam-potassium
French	-
German	-
Danish	-
Italian	-
Spanish	-
Greek	-
Polish	-
Swedish	-
Hungarian	-
Dutch	-

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Record last updated:	31/03/2021
Contact:	aeru@herts.ac.uk
Please cite as:	Lewis, K.A., Tzilivakis, J., Warner, D. and Green, A. (2016) An international database for pesticide risk assessments and management. Human and Ecological Risk Assessment: An International Journal, 22(4), 1050-1064. DOI: 10.1080/10807039.2015.1133242