Phoxim (Ref: OMS 1170)

Phoxim (Ref: OMS 1170)	Last updated: 12/09/2025
(Also known as: phoxime; BAY 5621)

GENERAL INFORMATION

Description

An obsolete organophosphate insecticide used to control external animal parasites

Examples of veterinary uses

Used topically to control mites, lice and other ectoparasites

Examples of species treated

Cattle; Sheep; Goats; Pigs

Approval status

VMR 2013/2033 approval status (GB/UK)

Not approved

EU Regulatory approval status

Not approved

Chemical structure

Isomerism

Phoxim exhibits geometrical isomerism, specifically E/Z (cis/trans) isomerism, due to the presence of a C=N double bond in its oxime functional group. The commercial form of phoxim is typically the (E)-isomer.

Chemical formula

C₁₂H₁₅N₂O₃PS

Canonical SMILES

CCOP(=S)(OCC)ON=C(C#N)C1=CC=CC=C1

Isomeric SMILES

CCOP(=S)(OCC)O/N=C(\C#N)/C1=CC=CC=C1

International Chemical Identifier key (InChIKey)

ATROHALUCMTWTB-WYMLVPIESA-N

International Chemical Identifier (InChI)

InChI=1S/C12H15N2O3PS/c1-3-15-18(19,16-4-2)17-14-12(10-13)11-8-6-5-7-9-11/h5-9H,3-4H2,1-2H3/b14-12+

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
chlorphoxim	Variant

General status

Veterinary substance type

Ectoparasitic agent

Other bioactivity & uses

Disinfectant

Substance groups

Organophosphate insecticide; Organophosphate acaricide; Organothiophosphate insecticide; Organothiophosphate acaricide

Minimum active substance purity

Known relevant impurities

Substance origin

Synthetic

Mode of action

Non-systemic with contact and stomach action. Short activity period. Acetylcholinesterase (AChE) inhibitor.

Molecular targets

[Cholinesterase, Inhibitor]

CAS RN

14816-18-3

EC number

238-887-3

CIPAC number

364

US EPA chemical code

598800

PubChem CID

9570290

CLP index number

015-100-00-X

Therapeutic Class

Antiparasitic products, insecticides & repellents: Organophosphorus compounds

ATCvet Code

QP53AF01

Controlled Drug?

Regulation 37/2010 MRL Classification

Molecular mass

298.3

PIN (Preferred Identification Name)

IUPAC name

O,O-diethyl α-cyanobenzylideneaminooxyphosphonothioate

CAS name

4-ethoxy-7-phenyl-3,5-dioxa-6-aza-4-phosphaoct-6-ene-8-nitrile 4-sulphide

Forever chemical

Other status information

OSPAR soc

Relevant Environmental Water Quality Standards

Physical state

Yellow liquid

Commercial

Property

Value

Availability status

Introduction & key dates

1970, introduced

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

FCC Ltd
Bayer CropScience
King Tech

Example products using this active

Superxim
Phoxim
Liben
Volaton

Formulation and application details

Available in a variety of formulations including aerosols, baits, dustable powders, emulsifiable concentrates, seed dressings, granules and ULV liquid.

Commercial production

Phoxim is synthesised through a multi-step chemical process that typically begins with the preparation of alpha-cyanobenzaldehyde oxime sodium, an intermediate formed by reacting benzyl alcohol with nitrite compounds under controlled conditions. This intermediate is then reacted with diethyl chlorothiophosphate, a phosphorus-containing reagent, to form the final phoxim molecule. Traditional methods often use volatile nitrites like ethyl or methyl nitrite, which pose safety risks due to their low boiling points and explosive potential. However, newer, greener methods have introduced high-boiling nitrites and optimised reaction conditions to improve safety, reduce waste, and increase yield.

Impact on climate of production and use

Data for the amount of life cycle GHGs produced by phoxim are not available in the public domain. However, whilst estimates vary, more general data suggests that between 14 and 19 kilograms of CO₂e is emitted per kilogram of insecticide produced.

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

1.5

Low

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

250000

Xylene

250000

Dichloromethane

250000

Acetone

136000

n-Heptane

Melting point (°C)

Boiling point (°C)

Decomposes on distillation

Degradation point (°C)

Flashpoint (°C)

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

2.40 X 10⁰³

Calculated

Log P

3.38

High

Fat solubility of residues

Solubility

Soluble

Data type

Regulatory data - observed in metabolism and farm animal feeding studies

Density (g ml⁻¹)

1.18

Dissociation constant pKa) at 25 °C

Vapour pressure at 20 °C (mPa)

2.1

Low volatility. If applied directly to plants or soil, drift is a concern & mitigation is advisable

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

4.18 X 10^-01

Moderately volatile

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)

Refractive Index

Environmental release

Degradation

Property

Value

Source; quality score; and other information

Interpretation

Soil degradation (days) (aerobic)

DT₅₀ (typical)

Non-persistent

DT₅₀ (lab at 20 °C)

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

Note

Best available data

Manure DT₅₀ (days)

Aqueous photolysis DT₅₀ (days) at pH 7

Value

Note

Aqueous hydrolysis DT₅₀ (days) at 20 °C and pH 7

Value

7.2

Non-persistent

Note

pH sensitive: DT₅₀ 26.7 days at pH 4, 3.1 days at pH 9, all at 22 °C

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)

33.33

Slightly mobile

K_foc (mL g⁻¹)

1148

¹/_n

1.03

Notes and range

K_f range 27.0-44.0 (802 for peat) mL g⁻¹, K_foc range 997-1243 (1333 for peat) mL g⁻¹, ¹/_n - no data, Soils=4

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

0.73

Calculated

Low leachability

Bio-concentration factor

BCF (l kg⁻¹)

1610

Whole body

Threshold for concern

CT₅₀ (days)

Not available

Known soil metabolites

Metabolite

Major/Minor fraction

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

Estimated maximum occurrence fraction

Notes

chlorphoxim (Ref: OMS 1197)

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)

113

Rat

Moderate

Mammals - Short term dietary NOEL

(mg kg⁻¹)

Rat 2 yr

(ppm diet)

> 15

Mammals - Chronic 21d NOAEL (mg kg⁻¹ bw d⁻¹)

Birds - Acute LD₅₀ (mg kg⁻¹)

Birds - Short term dietary (LC₅₀/LD₅₀)

Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)

Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹)

> 40.4

Eisenia foetida

Moderate

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

Soil micro-organisms

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)

> 0.22

Lepomis macrochirus

Moderate

Temperate Freshwater Fish - Chronic 21 day NOEC (mg l⁻¹)

Tropical Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

> 0.414

Danio rerio

Moderate

Temperate Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)

0.00081

Daphnia magna

High

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) (120 hr NOEC)

0.1

Anabaena variabilis

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)

113

Rat

Moderate

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

5000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

4.0

Rat

Other Mammal toxicity endpoints

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

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

AAOEL - Acute Acceptable Operator Exposure Level (mg kg⁻¹ bw day⁻¹)

AOEL - Acceptable Operator Exposure Level - Systemic (mg kg⁻¹ bw day⁻¹)

Dermal penetration studies (%)

Dangerous Substances Directive 76/464

List I; List II

Exposure Routes

Public

Occupational

Mammalian dose elimination route and rate

Phosmet is rapidly absorbed, distributed, and eliminated in mammals with ~75% lost in urine

Health issues

Specific human health issues

Carcinogen

Genotoxic

Endocrine disruptor

No data found

; ; ; ;

No data found

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

Respiratory tract irritant

Skin irritant

Skin sensitiser

Eye irritant

Phototoxicant

No data found

General human health issues

Harmful if swallowed

Handling issues

Property

Value and interpretation

General

Flammable

CLP classification 2013

Health: H302, H317, H361f
Environment: H400, H410

WHO Classification

II (Moderately hazardous)

UN Number

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

Light sensitive - store in the dark

TRANSLATIONS

Language

Name

English

phoxim

French

phoxime

German

Phoxim

Danish

phoxim

Italian

foxim

Spanish

foxim

Greek

phoxim

Polish

foksim

Swedish

foxim

Hungarian

Dutch

foxim

Norwegian

Record last updated:	12/09/2025
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