Propoxur (Ref: OMS 33)

Propoxur (Ref: OMS 33)	Last updated: 21/08/2024
(Also known as: arprocarb; PHC; propotox; ENT 25671)

SUMMARY

Propoxur is a carbamate pesticide. With a high aqueous solubility, it has potential for being mobile in groundwaters although it is rarely reported. It is not highly volatile. In some situations it may persist in soil systems. It is highly toxic to humans if it is ingested but no other serious health issues have been identified. There are gaps in information relating to the toxicity of propoxur to biodiversity but based on information that is available it likely to be moderately to highly toxic.

GENERAL INFORMATION

Description

An obsolete carbamate mode of actioninsecticide and acaricide active against a wide range of pests

Availability status

Current

Introduction & key dates

1959, introduced;1963, first registered US

Examples of veterinary uses

Used to eradicate external paraistes such as lice, fleas and ticks

Examples of species treated

Domestic animals including cats & dogs; Agricultural livestock

Approval status

VMR 2013/2033 approval status (GB/UK)

Not approved

EU Regulatory approval status

Not approved

Chemical structure

Isomerism

None

Chemical formula

C₁₁H₁₅NO₃

Canonical SMILES

CC(C)OC1=CC=CC=C1OC(=O)NC

Isomeric SMILES

International Chemical Identifier key (InChIKey)

ISRUGXGCCGIOQO-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C11H15NO3/c1-8(2)14-9-6-4-5-7-10(9)15-11(13)12-3/h4-8H,1-3H3,(H,12,13)

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
propoxur	-

General status

Veterinary substance type

Insecticide, Acaricide

Substance groups

Carbamate insecticide; Carbamate acaricide; Phenyl methylcarbamate insecticide; Phenylk methylcarbamate acaricide

Minimum active substance purity

Known relevant impurities

Substance origin

Synthetic

Mode of action

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

Molecular targets

[Cholinesterase, Inhibitor]

CAS RN

114-26-1

EC number

204-043-8

CIPAC number

US EPA chemical code

047802

PubChem CID

4944

CLP index number

006-016-00-4

Therapeutic Class

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

ATCvet Code

QP53AE02

Controlled Drug?

Regulation 37/2010 MRL Classification

Molecular mass

209.24

PIN (Preferred Identification Name)

IUPAC name

2-isopropoxyphenyl methylcarbamate

CAS name

2-(1-methylethoxy)phenyl methylcarbamate

Other status information

Marine Pollutant

Relevant Environmental Water Quality Standards

Physical state

White crystalline solid

Formulations

Property

Product

Manufacturer

Authorisation Route

Legal Class (GB/UK)

Example products (past and present) using this active

Beaphar Flea Spray

Beaphar (UK) Ltd

Not licensed

Bolfo 0.25% Flea Spray

Bayer plc

Not licensed

Formulation and application details

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

1800

High

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

200000

Isopropanol

94000

Toluene

1300

Hexane

Melting point (°C)

Boiling point (°C)

Decomposes on distillation

Degradation point (°C)

Flashpoint (°C)

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

1.38 X 10⁰⁰

Calculated

Log P

0.14

Low

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

1.18

Dissociation constant pKa) at 25 °C

Vapour pressure at 20 °C (mPa)

1.3

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)

1.50 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)

Moderately persistent

DT₅₀ (lab at 20 °C)

Moderately persistent

DT₅₀ (field)

Non-persistent

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

Note

Best available data

Manure DT₅₀ (days)

Aqueous photolysis DT₅₀ (days) at pH 7

Value

0.01

Fast

Note

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

Value

180

Persistent

Note

Water-sediment DT₅₀ (days)

Fast

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)

Mobile

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

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

3.65

Calculated

High leachability

Bio-concentration factor

BCF (l kg⁻¹)

Low risk

Rapid aquatic degradation

Low risk

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

2-(1-methylethoxy)phenol

Photolysis

Known groundwater metabolites

None

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

dimethyl propoxus

Plant

0.27-0.36

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)

200

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

Birds - Acute LD₅₀ (mg kg⁻¹)

> 25.9

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)

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

Soil micro-organisms

Collembola

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Non-target plants

Honeybees (Apis spp.)

Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)

< 0.112

Apis mellifera 24 hr

High

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)

> 1.35

Moderate

Chronic

Notes

[The residual time to 25% mortality (RT25) value for honeybees is 5 hrs - USEPA data]

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)

> 1.6

Bombus terrestris

Moderate

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)

Harmful

Chrysoperla carnea

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)

6.2

Lepomis macrochirus

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)

0.15

Daphnia magna

Moderate

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

0.016

Daphnia magna survival 42 day

Moderate

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)

38.1

Chironomus riparius 1 day

Moderate

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 - Acute 7 day EC₅₀, biomass (mg l⁻¹)

Algae - Acute 72 hour EC₅₀, growth (mg l⁻¹)

Algae - Chronic 96 hour NOEC, growth (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)

5000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 0.50

Rat

Other Mammal toxicity endpoints

Intraperitoneal LD₅₀ = 30 mg kg⁻¹

Rat

Intramuscular LD₅₀ = 53 mg kg⁻¹

Rat

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

0.02

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

Exposure Routes

Public

Occupational

Mammalian dose elimination route and rate

Absorbed through skin but in humans it is emininated, as its major metabolite 2-isopropoxyphenol (IPP), via urine within 24 hr of application

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

Toxic
US EPA - probable human carcinogen
Endocrine issues - Weak estrogenic effect

Handling issues

Property

Value and interpretation

General

IMDG Transport Hazard Class 6,1

CLP classification 2013

Health: H301
Environment: H400, H410

WHO Classification

II (Moderately hazardous)

UN Number

UN2757

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

propoxur

French

propoxur

German

Propoxur

Danish

propoxur

Italian

propoxur

Spanish

propoxur

Greek

propoxur

Polish

propoksur

Swedish

Hungarian

Dutch

propoxur

Norwegian

Record last updated:	21/08/2024
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