Napropamide (Ref: R 7465)

Napropamide (Ref: R 7465)	Last updated: 23/02/2021
(Not known by any other names)

SUMMARY

Napropamide is a widely used herbicide approved for use on the EU and many other countries. It has a low mammalian toxicity but is is a known skin and eye irritant. It is moderately soluble in water, and is quite volatile. It is moderately persistent in soil systems and data suggests that under certain conditions it may be persistent in water. It has a low toxicity to birds but is moderately toxic to most aquatic species, honeybees and earthworms.

GENERAL INFORMATION

Description

A soil applied herbicide for pre-emergence control of weeds in a range of crops including oilseed rape, fruit and woody ornamentals

Example pests controlled

Annual grasses; Broad-leaved weeds

Example applications

Vegetables, Fruit tree and bushes; Vines; Tobacco; Olives; Sunflowers; Turf; Oilseed rape; Ornamentals

Efficacy & activity

Availability status

Current

Introduction & key dates

circa 1970

UK regulatory status

UK COPR regulatory status

Approved

Date COPR inclusion expires

31/12/2026

UK LERAP status

None

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

Solvenia/Hungary

Date EC 1107/2009 inclusion expires

31/12/2023

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
✓		✓	✓		✓	✓	✓	✓

Also used in

Australia

Chemical structure

Isomerism

A ciral molecule. The technical material is a racemate composed of equimolar amounts of (S)- and (R)-napropamide.

Chemical formula

C₁₇H₂₁NO₂

Canonical SMILES

CCN(CC)C(=O)C(C)OC1=CC=CC2=CC=CC=C21

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

WXZVAROIGSFCFJ-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C17H21NO2/c1-4-18(5-2)17(19)13(3)20-16-12-8-10-14-9-6-7-11-15(14)16/h6-13H,4-5H2,1-3H3

2D structure diagram/image available?

Yes

General status

Pesticide type

Herbicide

Substance group

Alkanamide

Minimum active substance purity

930 g kg⁻¹

Known relevant impurities

EU dossier - toluene <0.14%

Substance origin

Synthetic

Mode of action

Selective, systemic, absorbed through roots and translocated. Acts by preventing root cell elongation and so disrupting growth. Inhibition of VLCFA (inhibition of cell division).

CAS RN

15299-99-7

EC number

239-333-3

CIPAC number

271

US EPA chemical code

103001

PubChem CID

27189

Molecular mass

271.36

PIN (Preferred Identification Name)

IUPAC name

(RS)-N,N-diethyl-2-(1-naphthyloxy)propionamide

CAS name

N,N-diethyl-2-(1-naphthalenyloxy)propanamide

Other status information

Potential groundwater contaminant; PAN listed Highly Hazardous Chemical

Relevant Environmental Water Quality Standards

Herbicide Resistance Classification (HRAC)

Herbicide Resistance Classification (WSSA)

Insecticide Resistance Classification (IRAC)

Not applicable

Fungicide Resistance Classification (FRAC)

Not applicable

Examples of recorded resistance

Physical state

Colourless crystals to light brown solid depending on purity

Formulations

Property

Value

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

Devrinol 45F
Jouster
Naprop

Example products using this active

AgriGuard
United Phosphorus
Globalchem
Stauffer

Formulation and application details

Usually supplied as a suspension concentrate, emulsifiable concentrate, wettable powder or ganules

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

74.0

Moderate

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

440000

Acetone

11100

n-Heptane

290000

Ethyl acetate

692000

Dichloromethane

Melting point (°C)

74.8

Boiling point (°C)

316.7

Degradation point (°C)

Flashpoint (°C)

Not expected to self ignite; Not highly flammable

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

2.00 X 10⁰³

Calculated

Log P

3.3

High

Bulk density (g ml⁻¹)

1.18

Dissociation constant pKa) at 25 °C

Not applicable

No dissociation

Vapour pressure at 20 °C (mPa)

2.2 X 10^-02

Low volatility

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

8.1 X 10^-05

Non-volatile

Maximum UV-vis absorption L mol⁻¹ cm⁻¹

Neutral solution 215nm = 58800, 282nm = 10500
Acidic solution 215nm = 58600, 282nm = 10900

Surface tension (mN m⁻¹)

66.0

at 20°C

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

Moderately persistent

DT₅₀ (lab at 20 °C)

308

Persistent

DT₅₀ (field)

Moderately persistent

DT₉₀ (lab at 20 °C)

1000

Very persistent

DT₉₀ (field)

290

DT₅₀ modelling endpoint

Note

EU dossier lab studies DT₅₀ range 120-400 days, DT₉₀ >1000 days; field studies DT₅₀ range 31-127 days, DT₉₀ range 180-400 days; Other sources: 8-12 weeks (R3)

Dissipation rate RL₅₀ on plant matrix

Value

Note

Dissipation rate RL₅₀ on and in plant matrix

Value

Note

Aqueous photolysis DT₅₀ (days) at pH 7

Value

1.5

Moderately fast

Note

Mid-European conditions

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

Value

Stable

Note

Stable pH 5 to pH 7, 25 and 40 °C

Water-sediment DT₅₀ (days)

316

Slow

Water phase only DT₅₀ (days)

Slow

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d

21.5

Slightly mobile

K_oc

839

Notes and range

EU dossier K_d range 6.87-47.4 mL g⁻¹, K_oc range 435-1609 mL g⁻¹, Soils=5

Freundlich

K_f

21.6

Slightly mobile

K_foc

885

¹/_n

0.815

Notes and range

EU dossier K_f range 8.1-44.5 mL g⁻¹, EU dossier K_foc range 409-1593 mL g⁻¹, ¹/_n range 0.720-0.815, Soils=5

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

1.96

Calculated

Transition state

SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate

Value

7.58 X 10^-02

Calculated

Note

Potential for particle bound transport index

Medium

Calculated

Potential for loss via drain flow

Slightly mobile

Calculated

Key metabolites

Metabolite

Formation medium

Estimated maximum occurrence fraction

1107/2009 relevancy

alpha-naphthoxy propionic acid

Soil

0.01

Minor fraction, Not relevant

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

Metabolising enzymes

N,N-diethyl-2-(4-hydroxynaphthalen-1-yl)propanamide

hydroxy napropamide isomer 1

a=Surface water (photolysis); b=Sediment

a=0.20

N,N-diethyl-2-(1-hydroxynaphthalen-2-yl)propanamide

hydroxy napropamide isomer 2

a=Surface water (photolysis); b=Sediment

a=0.27

N-ethylethanamine

diethylamine

a=Surface water (photolysis); b=Sediment

a=0.26

2-methylnaphtho[1,2-b]furan-3(2H)-one

MNF

a=Surface water (photolysis); b=Sediment

a=0.15

[4-glucuronyl-(N-ethyl-2-(1-naphthoxy)) propionamide]

4-OGlu-DE-NPAM

Rat (urine, faeces)

N-({4-[(1-amino-1-oxopropan-2-yl)oxy]naphthalen-1-yl}oxy)glutamic acid

4-OGlu-NOPAM

Rat (urine, faeces)

N-{[4-(1-carboxyethoxy)naphthalen-1-yl]oxy}glutamic acid

4-OGlu-NOPA

Rat (urine, faeces)

naphthalene-1,4-dione

Plant

2-hydroxynaphthalene-1,4-dione

HNQ

Plant

benzene-1,2-dicarboxylic acid

Plant

1-naphthol

Plant

[4-glucuronyl-(N,N-diethyl-2-(1-naphthoxy)) propionamide]

4-OGlu-NPAM

Rat (urine, faeces)

2,2'-(4,4'-dihydroxy-1,1'-binaphthalene-3,3'-diyl)bis(N,N-diethylpropanamide)

dimer

a=Surface water (photolysis); b=Sediment

a=0.09

ECOTOXICOLOGY

Property

Value

Source; quality score; and other information

Interpretation

Bio-concentration factor

BCF (l kg⁻¹)

Low potential

CT₅₀ (days)

Not available

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 4680

Rat

Low

Mammals - Short term dietary NOEL

(mg kg⁻¹)

Rat

High

(ppm diet)

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

> 100

Rat Reproductive NOAEL

Moderate

Birds - Acute LD₅₀ (mg kg⁻¹)

> 2250

Colinus virginianus

Low

Birds - Short term dietary (LC₅₀/LD₅₀)

> 7200 mg kg feed⁻¹

Anas platyrhynchos

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

309

Colinus virginianus NOAEL

Low

Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

6.6

Salmo gairdneri

Moderate

Fish - Chronic 21 day NOEC (mg l⁻¹)

1.1

Salmo gairdneri

Moderate

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

14.3

Daphnia magna

Moderate

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

4.3

Daphnia magna

Moderate

Aquatic crustaceans - Acute 96 hour LC₅₀ (mg l⁻¹)

3.1

Americamysis bahia

Moderate

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 - Acute 7 day EC₅₀, biomass (mg l⁻¹)

0.24

Lemna gibba

Moderate

Non-target plants

310

Avena fatua
Vegetative vigour, ER₅₀
as g ha⁻¹

> 4500

Avena fatua
Seedling emergence, ER₅₀
as g ha⁻¹

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

3.4

Pseudokirchneriella subcapitata

Moderate

Algae - Chronic 96 hour NOEC, growth (mg l⁻¹)

Honeybees (Apis spp.)

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

> 100

Apis mellifera

Low

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

> 100

Apis mellifera

Low

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

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 pollinators (1)

Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)

Mode of exposure

Other pollinators (2)

Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)

Mode of exposure

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

282.0

Eisenia foetida corr

Moderate

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

30.0

Eisenia foetida corr

Moderate

Other soil macro-organisms

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Other arthropod (1)

LR₅₀ g ha⁻¹

% Effect

0.0

Mortality [Dose: 4.5 kg ha⁻¹]
Typhlodromus pyri

Other arthropod (2)

LR₅₀ g ha⁻¹

% Effect

6.0

Mortality [Dose: 4.5 kg ha⁻¹]
Aphidius rhopalosiphi

Soil micro-organisms

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

Dose: 2.25 g ha⁻¹

Mesocosm study data

NOEAEC mg l⁻¹

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)

> 4680

Rat

Low

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

2000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 4.8

Rat 4 hr

Other Mammal toxicity endpoints

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

0.3

Rat SF=100

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

None allocated

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

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

0.5

Dog SF=100

Dermal penetration studies (%)

0.7-13.4

concentration dependent

Dangerous Substances Directive 76/464

Exposure Routes

Public

Risk to bystanders acceptable for proposed uses

Occupational

Risks identified for operators - PPE/PPC advised

MRLs

European

EU MRL pesticide database

Notes

Drinking Water Standards

Drinking Water MAC (μg l⁻¹)

Health issues

Specific human health issues

Carcinogen

Genotoxic

Endocrine disruptor

; ; ; ;

No data found

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

Possible liver and kidney toxicant

Handling issues

Property

Value and interpretation

General

Not explosive or oxidising
IMDG Transport Code is usually 9

CLP classification 2013

Health: H319
Environment: H410, H411

EC Risk Classification

N - Dangerous for the environment: R50, R53

EC Safety Classification

WHO Classification

U (Unlikely to present an acute hazard)

UN Number

Usually 3082

Waste disposal & packaging

Packaging Group III (minor danger)

TRANSLATIONS

Language

Name

English

napropamide

French

napropamide

German

Napropamid

Danish

napropamid

Italian

napropamide

Spanish

napropamida

Greek

Polish

napropamid

Swedish

napropamid

Hungarian

napropamid

Dutch

Record last updated:	23/02/2021
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