Zinc phosphide

Zinc phosphide	Last updated: 29/08/2025
(Also known as: zincphos; zinc diphosphide)

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 Warning: Significant data are missing	Ecotoxicity High alert: Birds acute ecotoxicity: High	Human health High alert: Mammals acute toxicity: High; Reproduction/development effects

GENERAL INFORMATION

Description

Used in bait products for the control of rodents in a variety of situations

Example pests controlled

Rats; Mice; Pocket gophers; Meadow voles

Example applications

Agricultural crops; Vegetables; Ornamentals; Orchards; Crop storage.

Efficacy & activity

Appearance and life cycle

Taxonomic classification

GB regulatory status

GB COPR regulatory status

Not approved

Date COPR inclusion expires

Withdrawn

GB LERAP status

No UK approval for use as a plant protection agent

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

Austria/Germany

Date EC 1107/2009 inclusion expires

31/12/2026

EU Candidate for substitution (CfS)

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

Zn₃P₂

Canonical SMILES

P=[Zn].P=[Zn].[Zn]

Isomeric SMILES

International Chemical Identifier key (InChIKey)

HOKBIQDJCNTWST-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/2P.3Zn

2D structure diagram/image available?

Yes

General status

Biopesticide type

Rodenticide

Substance groups

Inorganic compound

Minimum active substance purity

>800 g kg⁻¹

Known relevant impurities

EU dossier - none declared

Substance origin

Synthetic

Mode of action

Toxicity caused by the production of phosphine under acid conditions in the rodents stomach. Phosphine, a nerve toxin, has respiratory action, mitochondrial complex IV electron transport inhibitor

Substance source

Uses

Target pests

Target host

Farming system suitability

CAS RN

1314-84-7

EC number

215-244-5

CIPAC number

US EPA chemical code

088601

PubChem CID

25113606

CLP index number

015-006-00-9

Molecular mass

258.1

PIN (Preferred Identification Name)

IUPAC name

trizinc diphosphide

CAS name

zinc phosphide

Forever chemical

Other status information

PAN listed Highly Hazardous Chemical

Relevant Environmental Water Quality Standards

Herbicide Resistance Class (HRAC MoA class)

None allocated

Herbicide Resistance Class (WSSA MoA class)

None allocated

Insecticide Resistance Class (IRAC MoA class)

None allocated

Fungicide Resistance Class (FRAC MOA class)

Examples of recorded resistance

Physical state

Grey-black coloured powder with strong characteristic odour

Related substances & organisms

phosphane

Commercial

Property

Value

Availability status

Current

Introduction & key dates

1947, first registered USA.

Example manufacturers & suppliers of products using this active now or historically

Example products using this active

Arrex E Köder
Blue-Ox
Zinc-Tox
Gopha-Rid

Formulation and application details

Usually formulated as bait or tracking powder

Commercial production

Zinc phosphide is typically produced by a direct synthesis method involving the reaction of metallic zinc powder with red phosphorus. The two components are mixed in a precise mass ratio, usually around 3.1 to 3.3 parts zinc to 1 part phosphorus, and placed into a high-purity graphite boat. This mixture is then introduced into a smelting furnace under a protective inert gas atmosphere, such as nitrogen or argon, to prevent unwanted oxidation. The sealed furnace is gradually heated, often between 100°C and 900°C, allowing the elements to react and form zinc phosphide.

Impact on climate of production and use

Data for the amount of life cycle GHGs produced by zinc phosphide are not available in the public domain. However, whilst estimates vary, more general data suggests that between 14 and 30 kilograms of CO₂e is emitted per kilogram of substance produced.

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

Solubility - In water at 20 °C (mg l⁻¹)

0.0014

Low

Solubility - In organic solvents at 20 °C (mg l⁻¹)

500

n-Heptane

500

Xylene

500

Methanol

500

Acetone

Melting point (°C)

500

Boiling point (°C)

500

Degradation point (°C)

500

Flashpoint (°C)

Octanol-water partition coefficient at pH 7, 20 °C

Log P

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

Dissociation constant pKa) at 25 °C

Vapour pressure at 20 °C (mPa)

6.5 X 10^-06

Low volatility

Henry's law constant at 25 °C (Pa m³ mol⁻¹)

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)

72.8

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

10.95

Non-persistent

DT₅₀ (lab at 20 °C)

10.95

Non-persistent

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

EU dossier lab studies DT₅₀ range 7.8-14.1 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

Stable

Note

Stable at pH 5 to 9 and 20 °C, at pH4 DT₅₀ = 38 days

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

K_d (mL g⁻¹)

K_oc (mL g⁻¹)

Notes and range

Freundlich

K_f (mL g⁻¹)

K_foc (mL g⁻¹)

¹/_n

Notes and range

pH sensitivity

Known soil metabolites

Metabolite

Major/Minor fraction

$Click here for further information on Major/Minor fraction$

Estimated maximum occurrence fraction

Notes

phosphane

Major fraction

1.00

Known groundwater metabolites

None

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

hypophosphite

Mammal (Urine); Animal

phosphite

Mammal (Urine); Animal

phosphonic acid

Air (photo-oxidation)

phosphoric acid

Air (photo-oxidation)

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

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)

12.9

Colinus virginianus

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)

> 1000

Eisenia foetida

Low

Earthworms - Chronic NOEC, reproduction (mg kg⁻¹)

Soil micro-organisms

Nitrogen mineralisation: No significant adverse effect
Carbon mineralisation: No significant adverse effect

Dose = 240 g ha⁻¹ 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)

> 21.7

Leuciscus idus

Moderate

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)

114

Daphnia magna

Low

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) (72 hr ErC₅₀, Static)

0.00375

Desmodesmus subspicatus

High

Algae - Chronic (growth rate, fresh; mg l⁻¹) (72 hr NOEC, Static)

0.0014

Desmodesmus subspicatus

Moderate

Mesocosm study data

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)

Rat

High

Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)

1000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 11

Rat

Other Mammal toxicity endpoints

ADI - Acceptable Daily Intake (mg kg⁻¹ bw day⁻¹)

0.042

Rat SF=100

ARfD - Acute Reference Dose (mg kg⁻¹ bw day⁻¹)

0.073

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)

0.042

Rat SF=100

Dermal penetration studies (%)

default

Dangerous Substances Directive 76/464

Exposure Routes

Public

Negligible risk for bystanders

Occupational

Acceptable risk for workers

Mammalian dose elimination route and rate

Health issues

Specific human health issues

Carcinogen

Genotoxic

Endocrine disruptor

; ; ; ;

No data found

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

No data found

Respiratory tract irritant

Skin irritant

Skin sensitiser

No data found

Eye irritant

Phototoxicant

No data found

General human health issues

Highly toxic in phosphine form
May be fatal if swallowed

Handling issues

Property

Value and interpretation

General

Not explosive or oxidising
Contact with acids liberates very toxic gas
Moisture sensitive
Not expected to auto-ignite; Not highly flammable
IMDG Transport Hazard Class 4.3

CLP classification 2013

Health: H300
Handling: H260
Environment: H400, H410

WHO Classification

Ib (Highly hazardous)

UN Number

UN1714

Waste disposal & packaging

Packaging Group 1 (great danger)

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

zinc phosphide

French

phosphure de zinc

German

Zinkphosphid

Danish

Italian

zinco (fosfuro di)

Spanish

Greek

Polish

Swedish

Hungarian

Dutch

zinkfosfide

Norwegian

Record last updated:	29/08/2025
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