Magnesium phosphide	Last updated: 30/10/2025
(Also known as: phosphine; trimagnesium phosphorus(-3) anion )

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Hazard alerts

The following alerts are based on the data in the tables below. An absence of an alert does not imply the substance has no implications for human health, biodiversity or the environment but just that we do not have the data to form a judgement. These hazard alerts do not take account of usage patterns or exposure, thus do not represent risk.

Environmental fate	Ecotoxicity	Human health
Environmental fate Low alert: Non-persistent; Potential for particle bound transport: Low Warning: Significant data are missing	Ecotoxicity High alert: Birds acute ecotoxicity: High; Fish acute ecotoxicity: High	Human health High alert: Mammals acute toxicity: High

GENERAL INFORMATION

Description	A phosphine generating compound used against vertebrates and grain store pests
Example pests controlled	Burrowing rodents and moles; Grain insect pests
Example applications	Animal feeds; Tobacco; Processed food commodities; Indoor areas and uncropped land; Bulked grain
Efficacy & activity	-
Appearance and life cycle	-
Taxonomic classification	-

GB regulatory status

GB COPR regulatory status	Approved
Date COPR inclusion expires	31/08/2031
GB LERAP status	None

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status	Approved
Dossier rapporteur/co-rapporteur	Austria/Estonia
Date EC 1107/2009 inclusion expires	30/11/2026
EU Candidate for substitution (CfS)	No
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 ✓   ✓ ✓ ✓ ✓   ✓ ✓
Approved for use (✓) under EC 1107/2009 by Mutual Recognition of Authorisation and/or national regulations in the following EEA countries	ISIceland NONorway

Additional information

Known to be also used in the following countries	-

Chemical structure

Isomerism	None
Chemical formula	Mg₃P₂
Canonical SMILES	[Mg+2].[Mg+2].[Mg+2].[P-3].[P-3]
Isomeric SMILES	-
International Chemical Identifier key (InChIKey)	VUBDMGXNLNDGIY-UHFFFAOYSA-N
International Chemical Identifier (InChI)	InChI=1S/3Mg.2P/q3*+2;2*-3
2D structure diagram/image available?	Yes

General status

Biopesticide type		Insecticide; Rodenticide
Substance groups		Inorganic compound
Minimum active substance purity		880 g kg⁻¹
Known relevant impurities		EU dossier - None declared
Substance origin		Synthetic
Mode of action		Nerve toxin with respiratory action - reacts with stomach acids to produce phosphine. Mitochondrial complex IV electron transport inhibitor.
Substance source		-
Uses		-
Target pests		-
Target host		-
Farming system suitability		-
CAS RN		12057-74-8
EC number		235-023-7
CIPAC number		228
US EPA chemical code		066504
PubChem CID		magnesium phosphide
CLP index number		015-005-00-3
Molecular mass		134.86
PIN (Preferred Identification Name)		magnesium phosphide
IUPAC name		magnesium phosphide
CAS name		magnesium phosphide
Listed (✓) under		UK Poisons List Order 1972 Rotterdam Convention Montreal Protocol ✓Yes The Poisons List Order 1972 XNo Rotterdam Convention XNo Montreal Protocol Stockholm Convention OSPAR EU Water Framework Directive XNo Stockholm Convention XNo OSPAR XNo EU Water Framework Directive
Relevant Environmental Water Quality Standards		-
Forever chemical		-
Highly Hazardous Pesticide (HHP)	Type I	-
	Type II	Yes [ R09 Rule 9: Pesticide active ingredients that have demonstrated a high aquatic toxicity (where acute ecotoxicity for fish, invertebrates or algae =< 0.1 mg l⁻¹) ]
Other status information		-
Herbicide Resistance Class (HRAC MoA class)		Not applicable
Herbicide Resistance Class (WSSA MoA class)		Not applicable
Insecticide Resistance Class (IRAC MoA class)		24A
Fungicide Resistance Class (FRAC MOA class)		Not applicable
Examples of recorded resistance		-
Physical state		Grey solid

Commercial

Property	Value
Availability status	Current
Introduction & key dates	1979, first registered USA
Example manufacturers & suppliers of products using this active now or historically	Detia Degesch GmbH Rentokil
Example products using this active	Degesch Plates
Formulation and application details	Formulated into pellets, tablets, or powder blends for use as a phosphine gas generating product
Commercial production	Magnesium phosphide is commercially produced by reacting elemental magnesium with red phosphorus under controlled high-temperature conditions. The synthesis involves heating magnesium metal and red phosphorus in an inert atmosphere to prevent unwanted oxidation, typically in sealed reactors at temperatures around 500–750 DegC. The reaction yields magnesium phosphide. After cooling, the product is ground and stabilized with inert carriers or coatings to reduce its sensitivity to water and air.
Impact on climate of production and use	Data on the amount of CO₂-e emitted during the production of magnesium phosphide is not readily available. However, it can be estimated from existing data for similar production processes. Estimates suggest that the CO₂-e emissions for producing magnesium phosphide likely range between 2.5 to 5.5 kg CO₂-e per kg of product, depending on energy sources and production scale.

ENVIRONMENTAL FATE

Property		Value	Source; quality score; and other information	Interpretation
Solubility - In water at 20 °C at pH 7 (mg l⁻¹)		No data	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 - rapid hydrolysis	No data
Solubility - In organic solvents at 20 °C (mg l⁻¹)		Insoluble	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 Most organic solvents	-
Melting point (°C)		Decomposes before melting	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	-
Boiling point (°C)		Decomposes before boiling	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	-
Degradation point (°C)		500	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	-
Flashpoint (°C)		-	-	-
Octanol-water partition coefficient at pH 7, 20 °C	P	-	-	-
	Log P	-	-	-
Fat solubility of residues	Solubility	-	-	-
	Data type	-	-	-
Density (g ml⁻¹)		1.47	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	-
Dissociation constant pKa) at 25 °C		No data	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	-
		Can not determine due to rapid hydrolysis
Vapour pressure at 20 °C (mPa)		1.0 X 10-05	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	Low volatility
Henry's law constant at 25 °C (Pa m³ mol⁻¹)		No data	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 - rapid hydrolysis	No data
Volatilisation as max % of applied dose lost	From plant surface	-	-	-
	From soil surface	-	-	-
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)	0.24	Q3 Q = Miscellaneous data from online sources 3 = Unverified data of known source	Non-persistent
	DT₅₀ (lab at 20 °C)	0.22	A4 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 ) 4 = Verified data	Non-persistent
	DT₅₀ (field)	-	-	-
	DT₉₀ (lab at 20 °C)	0.69	A4 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 ) 4 = Verified data	Non-persistent
	DT₉₀ (field)	-	-	-
	DT₅₀ modelling endpoint	-	-	-
	Note	EU dossier lab studies DT₅₀ range 0.22-0.24 days, DT₉₀ estimated range 0.66-0.72 days
Dissipation rate RL₅₀ (days) on plant matrix	Value	-	-	-
	Note	-
Dissipation rate RL₅₀ (days) 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	Very rapid	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	Very rapid
	Note	-
Water-sediment DT₅₀ (days)		-	-	-
Water phase only DT₅₀ (days)		-	-	-
Sediment phase only DT₅₀ (days)		-	-	-
Air degradation		As this parameter is not normally measured directly, a surrogate measure is used: ‘Photochemical oxidative DT₅₀’. Where data is available, this can be found in the Fate Indices section below.
Decay in stored produce DT₅₀		-

Soil adsorption and mobility

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

Known soil metabolites

Metabolite	Major/Minor fraction	Estimated maximum occurrence fraction	Notes
phosphane	Major fraction	1.00	-

Known groundwater metabolites

None

Other known metabolites

None

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property		Value	Source; quality score; and other information	Interpretation
Mammals - Acute oral LD₅₀ (mg kg⁻¹)		10.4	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 Rat	High
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)		49	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 Coturnix japonica	High
Birds - Short term dietary (LC₅₀/LD₅₀)		-	-	-
Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)		-	-	-
Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹ dw soil)		> 663.5	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 as aluminium phosphide	Moderate
Earthworms - Chronic NOEC, reproduction (mg kg⁻¹ dw soil)		-	-	-
Soil micro-organisms		Nitrogen mineralisation: No significant adverse effect Carbon mineralisation: No significant adverse effect	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 Dose: 56% AIP/kg soil 28 Day	-
Collembola	Acute LC₅₀ (mg kg⁻¹)	-	-	-
	Chronic NOEC (mg kg⁻¹)	-	-	-
Non-target plants	Vegetative vigour ER₅₀ (g ha⁻¹)	-	-	-
	Seedling emergence ER₅₀ (g ha⁻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)	-	-	-
	Chronic	-	-	-
	Notes	-
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 bee species (1)	Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)	-	-	-
	Mode of exposure	-
Other bee species (2)	Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)	-	-	-
	Mode of exposure	-
Beneficial insects (Ladybirds)		-	-	-
Beneficial insects (Lacewings)		-	-	-
Beneficial insects (Parasitic wasps)		-	-	-
Beneficial insects (Predatory mites)		-	-	-
Beneficial insects (Ground beetles)		-	-	-

Aquatic ecotoxicology

Property		Value	Source; quality score; and other information	Interpretation
Temperate Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)		0.0093	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 Oncorhynchus mykiss calculated from phosphine	High
Temperate Freshwater Fish - Chronic 21 day NOEC (mg l⁻¹)		-	-	-
Tropical Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)		-	-	-
Temperate Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)		-	-	-
Temperate Freshwater Aquatic invertebrates - Chronic 21 day NOEC (mg l⁻¹)		-	-	-
Tropical Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (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 (free-floating, fonds growth, fresh) - 7 day (mg l⁻¹)		-	-	-
Aquatic plants (rooted, growth rate, fresh) - 14 day (mg l⁻¹)		-	-	-
Algae - Acute (growth rate, fresh; mg l⁻¹)		-	-	-
Algae - Chronic (growth rate, fresh; mg l⁻¹)		-	-	-
Mesocosm study data	NOEAEC mg l⁻¹	-	-	-
	NOEAEC mg l⁻¹	-	-	-
Marine bivalves		-	-	-

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)		10.4	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 Rat	High
Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)		460	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 Rat	-
Mammals - Inhalation LC₅₀ (mg l⁻¹)		> 11	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 Rat	-
Other Mammal toxicity endpoints		-	-	-
ADI - Acceptable Daily Intake (mg kg⁻¹ bw day⁻¹)		0.022	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 Rat SF=100	-
ARfD - Acute Reference Dose (mg kg⁻¹ bw day⁻¹)		0.038	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 Rat SF=100	-
AAOEL - Acute Acceptable Operator Exposure Level (mg kg⁻¹ bw day⁻¹)		-	-	-
AOEL - Acceptable Operator Exposure Level - Systemic (mg kg⁻¹ bw day⁻¹)		0.022	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 Rat SF=100	-
Dermal penetration studies (%)		-	-	-
Dangerous Substances Directive 76/464		-	-	-
Exposure Routes	Public	Acceptable risk for bystanders
	Occupational	Acceptable risk for workers Acceptable risk for operators for the control of rodents, PPE required for insect control
Mammalian dose elimination route and rate		-	-	-

Health issues

Specific human health issues (hazard-based)		Carcinogen Genotoxic Endocrine disruptor XNo, known not to cause a problem A0 A = Chromosome aberration (EFSA database) 0 = No data ; B0 B = DNA damage/repair (EFSA database) 0 = No data ; C3 C = Gene mutation (EFSA database) 3 = Negative ; D0 D = Genome mutation (EFSA database) 0 = No data ; E3 E = Unspecified genotoxicity type (miscellaneous data source) 3 = Negative No data found Reproduction / development effects Acetyl cholinesterase inhibitor Neurotoxicant ?Possibly, status not identified XNo, known not to cause a problem XNo, known not to cause a problem Respiratory tract irritant Skin irritant Skin sensitiser ✓Yes, known to cause a problem XNo, known not to cause a problem No data found Eye irritant Phototoxicant   ?Possibly, status not identified No data found
General human health issues		Moderately toxic

Handling issues

Property	Value and interpretation
General	Reacts with water to produce toxic phosphine (hydrogen phosphide, PH3 ) Not explosive or oxidising; IMDG Transport Hazard Class 4.3, 6.1
CLP classification 2013	Health: H300, H311 Handling: H260 Environment: H400
WHO Classification	Not classified: Fumigant (Not classified: Fumigant)
UN Number	UN2011
Waste disposal & packaging	Packaging Group I (great danger)
Shelf-life, storage, stability and reactivity	-

TRANSLATIONS

Language	Name
English	magnesium phosphide
French	diphosphure de trimagnésium
German	Trimagnesiumdiphosphid
Danish	-
Italian	-
Spanish	difosfuro de trimagnesio
Greek	-
Polish	fosforek magnezu
Swedish	-
Hungarian	-
Dutch	-
Norwegian	-

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Record last updated:	30/10/2025
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