Crufomate

Crufomate	Last updated: 04/09/2025
(Also known as: amidofos; crufomatum; ruelene)

GENERAL INFORMATION

Description

An obsolete topical organophosphate insecticide

Examples of veterinary uses

Once used to control of grubs, lice, and horn fly

Examples of species treated

Cattle

Approval status

VMR 2013/2033 approval status (GB/UK)

Not approved

EU Regulatory approval status

Not approved

Chemical structure

Isomerism

Crufomate exhibits stereoisomerism, specifically chirality, due to the presence of a chiral phosphorus atom in its molecular structure. This molecule exists as two enantiomers. In commercial formulations, crufomate is typically supplied as a racemic mixture, containing equal amounts of both enantiomers.

Chemical formula

C₁₂H₁₉ClNO₃P

Canonical SMILES

CC(C)(C)C1=CC(=C(C=C1)OP(=O)(NC)OC)Cl

Isomeric SMILES

International Chemical Identifier key (InChIKey)

BOFHKBLZOYVHSI-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C12H19ClNO3P/c1-12(2,3)9-6-7-11(10(13)8-9)17-18(15,14-4)16-5/h6-8H,1-5H3,(H,14,15)

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
crufomate	-

General status

Veterinary substance type

Insecticide

Substance groups

Organophosphate Insecticide

Minimum active substance purity

Known relevant impurities

Substance origin

Synthetic

Mode of action

Systemic, acts via the uncoupling of oxidative phosphorylation. Acetylcholinesterase (AchE) inhibitor.

Molecular targets

[Cholinesterase, Inhibitor]

CAS RN

299-86-5

EC number

206-083-1

CIPAC number

122

US EPA chemical code

012101

PubChem CID

9300

Therapeutic Class

ATCvet Code

None allocated

Controlled Drug?

Regulation 37/2010 MRL Classification

Molecular mass

291.71

PIN (Preferred Identification Name)

IUPAC name

N-[(4-tert-butyl-2-chlorophenoxy)-methoxyphosphoryl]methanamine

CAS name

2-chloro-4-(1,1-dimethylethyl)phenyl methyl methylphosphoramidate

Forever chemical

Other status information

Relevant Environmental Water Quality Standards

Physical state

Colourless crystalline powder

Commercial

Property

Value

Availability status

Considered obsolete but may be available in some countries

Introduction & key dates

1959, first reported

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

DowElanco

Example products using this active

Ruelene

Formulation and application details

Typically supplied as an oily liquid designed for topical veterinary use

Commercial production

The production of crufomate involves the esterification of a substituted phenol with a phosphoramidate derivative. The process begins with 4-tert-butyl-2-chlorophenol, which reacts with dimethyl phosphoramidic dichloride under controlled conditions, typically in the presence of a base like triethylamine to neutralise the hydrochloric acid byproduct. This reaction forms the key O,O-dimethyl O-(4-tert-butyl-2-chlorophenyl) phosphoramidate structure. The synthesis requires anhydrous conditions and temperature regulation to ensure high yield and purity.

Impact on climate of production and use

Data for the amount of life cycle GHGs produced by crufomate 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)

200

at 25 °C

Moderate

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

Melting point (°C)

Boiling point (°C)

118

Degradation point (°C)

Flashpoint (°C)

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

2.63 X 10⁰³

Calculated

Log P

3.42

High

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

Dissociation constant pKa) at 25 °C

Vapour pressure at 20 °C (mPa)

106

at 25 °C

Highly volatile. 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)

2.53 X 10^-04

Non-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)

DT₅₀ (lab at 20 °C)

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

Note

Manure DT₅₀ (days)

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)

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)

Slightly mobile

K_oc (mL g⁻¹)

1700

Notes and range

Estimated

Freundlich

K_f (mL g⁻¹)

K_foc (mL g⁻¹)

¹/_n

Notes and range

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

Bio-concentration factor

BCF (l kg⁻¹)

230

(Other literature Log BCF range -1.4 - 0.4 ())

Threshold for concern

CT₅₀ (days)

Not available

Known metabolites

None

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

860

Rat

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)

100

Wild bird

Moderate

Birds - Short term dietary (LC₅₀/LD₅₀)

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

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

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)

Oncorhynchus mykiss

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)

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

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)

860

Rat

Moderate

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

2000

Rabbit

Mammals - Inhalation LC₅₀ (mg l⁻¹)

Other Mammal toxicity endpoints

Subcutaneous LDLo = 50 mg kg⁻¹

Guinea pig

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

0.1

JMPR 1968

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

Exposure Routes

Public

Occupational

Possible risk as substance may be absorbed via inhalation, ingestion, skin and/or eye contact

Mammalian dose elimination route and rate

Eliminated rapidly as hydrolysis products. However, residues have been found in milk and milk products.

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

Moderately toxic
May cause respiratory problems

Handling issues

Property

Value and interpretation

General

Combustable
Prevent generation of dust
IMDG Transport Hazard Class 6.1
Not expected to auto-ignite

CLP classification 2013

WHO Classification

III (Slightly hazardous)

UN Number

UN3278

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

crufomate

French

crufomate

German

Crufomat

Danish

Italian

Spanish

crufomato

Greek

Polish

Swedish

Hungarian

Dutch

Norwegian

Record last updated:	04/09/2025
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