Propetamphos (Ref: OMS 1502)

Propetamphos (Ref: OMS 1502)	Last updated: 04/09/2025
(Also known as: safrotin; SAN 521391)

GENERAL INFORMATION

Description

An obsolete organophosphate insecticide and acaricide

Examples of veterinary uses

Mainly used to control cockroaches, flies, ants, ticks, moths, fleas and mosquitoes in livestock situations

Examples of species treated

Sheep

Approval status

VMR 2013/2033 approval status (GB/UK)

Not approved

EU Regulatory approval status

Not approved

Chemical structure

Isomerism

Propetamophos is a chiral molecule. The technical material tends to consist of 4 isomer: 2 geometric isomers (cis & trans) and 2 optical isomers (S- and R-). The S-form is the dominate isomer and usually exceeds 90% of the techincal material.

Chemical formula

C₁₀H₂₀NO₄PS

Canonical SMILES

CCNP(=S)(OC)OC(=CC(=O)OC(C)C)C

Isomeric SMILES

CCNP(=S)(OC)O/C(=C/C(=O)OC(C)C)/C

International Chemical Identifier key (InChIKey)

BZNDWPRGXNILMS-VQHVLOKHSA-N

International Chemical Identifier (InChI)

InChI=1S/C10H20NO4PS/c1-6-11-16(17,13-5)15-9(4)7-10(12)14-8(2)3/h7-8H,6H2,1-5H3,(H,11,17)/b9-7+/f/h11H

2D structure diagram/image available?

Yes

General status

Veterinary substance type

Insecticide, Acaricide, Antiparasitic, Sheep dip

Substance groups

Organophosphate insecticide; Organophosphate acaricide; Phosphoramidothioate insecticide; Phosphoramidothioate acaricide

Minimum active substance purity

Known relevant impurities

Substance origin

Synthetic

Mode of action

Contact and stomach action with long residual activity; Acetylcholinesterase (AChE) inhibitor.

Molecular targets

[Cholinesterase, Inhibitor]

CAS RN

31218-83-4

EC number

250-517-2

CIPAC number

394

US EPA chemical code

113601

PubChem CID

5372405

CLP index number

015-136-00-6

Therapeutic Class

Antiparasitic products, insecticides & repellents: Ecoparasiticides, insecticides & repellents

ATCvet Code

QP53AF09

Controlled Drug?

Regulation 37/2010 MRL Classification

Molecular mass

281.31

PIN (Preferred Identification Name)

IUPAC name

(RS)-[(E)-O-2-isopropoxycarbonyl-1-methylvinyl O-methyl ethylphosphoramidothioate]

CAS name

1-methylethyl (2E)-3-[[(ethylamino)methoxyphosphinothioyl]oxy]-2-butenoate

Forever chemical

Other status information

Marine, Surface and Groundwater Pollutant; PAN listed Highly Hazardous Chemical

Relevant Environmental Water Quality Standards

UK non-statutory standard for the protection of aquatic life: freshwater and saltwater annual average; 0.03 µg l⁻¹, max acceptable conc: 0.1 µg l⁻¹

Physical state

Oily yellow liquid

Commercial

Property

Value

Availability status

Current

Introduction & key dates

Circa 1975, introduced

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

Sandoz

Example products using this active

Safrotin

Formulation and application details

Usually supplied as a liquid concentrate for application as spot, surface, and crack and crevice treatments via low pressure spray or injected into the soil for termites.

Commercial production

Propetamphos is synthesised through a multi-step process involving the formation of a thiophosphoric acid ester. The key reaction centres on the condensation of ethylamino methanol with phosphorothioic dichloride, forming an intermediate phosphorothioate. This intermediate is then reacted with a butenoic acid ester derivative, specifically (E)-1-methylethyl 3-hydroxy-2-butenoate, to yield the final compound: O,O-diethyl alpha-(ethylaminomethoxy)phosphorothioate ester of crotonic acid. The synthesis requires precise control of stereochemistry, as propetamphos exists in multiple isomeric forms.

Impact on climate of production and use

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

110

at 24 °C

Moderate

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

Miscible

Ethanol

Miscible

Methanol

Miscible

Xylene

Miscible

Hexane

Melting point (°C)

Not applicable

Boiling point (°C)

Degradation point (°C)

Flashpoint (°C)

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

6.61 X 10⁰³

Calculated

Log P

3.82

High

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

1.13

Dissociation constant pKa) at 25 °C

13.67

Strong base

Vapour pressure at 20 °C (mPa)

1.9

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)

4.87 X 10^-03

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

1.495

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)

Moderately persistent

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

Note

Best available data

Manure DT₅₀ (days)

Aqueous photolysis DT₅₀ (days) at pH 7

Value

Stable

Note

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

Value

120

Persistent

Note

Other data: DT₅₀ 11 days at pH 3, 1 year at pH 6, 41 days at pH 9, all at 25 °C (L3)

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)

Moderately mobile

K_oc (mL g⁻¹)

330

Notes and range

Best available data

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

2.19

Calculated

Transition state

Bio-concentration factor

BCF (l kg⁻¹)

352

Estimated

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)

Rat

High

Mammals - Short term dietary NOEL

(mg kg⁻¹)

Rat 2 yr

(ppm diet)

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

Birds - Acute LD₅₀ (mg kg⁻¹)

Anas platyrhynchos

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)

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)

4.6

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)

0.015

Daphnia magna

High

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

0.0001

Daphnia magna

High

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) (EC₅₀)

2.9

Raphidocelis subcapitata

Moderate

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)

Rat

High

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

2260

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

0.69

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

In mammals it is completely metabolised and excreted via urine and exhaled air

Health issues

Specific human health issues

Carcinogen

Genotoxic

Endocrine disruptor

; ; ; ;

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

Respiratory tract irritant

Skin irritant

Skin sensitiser

No data found

Eye irritant

Phototoxicant

No data found

General human health issues

No further information available

Handling issues

Property

Value and interpretation

General

IMDG Transport Hazard Class 6.1

CLP classification 2013

Health: H301
Environment: H400, H410

WHO Classification

Ib (Highly hazardous)

UN Number

UN3018

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

propetamphos

French

propetamphos

German

Propetamphos

Danish

propetamphos

Italian

propetamfos

Spanish

propetamfos

Greek

propetamphos

Polish

propetamfos

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