Naproanilide

Naproanilide	Last updated: 23/02/2021
(Also known as: naproanalide; BRN 2746253)

SUMMARY

Naproanilide is a rice herbicide not used in the EU. It itself has no herbicidal activity however its major metabolite 2-(2-naphthoxy)propionic acid does. It is only slightly toxic. Photodegradation appears to be the main degradation pathway in paddy fields. Little is known about naproanilides toxicity to wildlife.

GENERAL INFORMATION

Description

A selective herbicide used for the control of weeds in rice paddy fields.

Example pests controlled

Broad-leaved weeds; Annual and perennial Cyperaceous weeds

Example applications

Rice

Efficacy & activity

Availability status

Unknown

Introduction & key dates

circa 1981

UK regulatory status

UK COPR regulatory status

Not approved

Date COPR inclusion expires

Not applicable

UK LERAP status

No UK approval for use

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Not approved

Dossier rapporteur/co-rapporteur

Not applicable

Date EC 1107/2009 inclusion expires

Not applicable

EU Candidate for substitution (CfS)

Not applicable

Listed in EU database

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

Chemical structure

Isomerism

Naproanilide is a chiral molecule and the technical material is an isomeric mixture of the S- and R-isomeric forms. The R-form exhibits the strongest herbicidal activity and is around 8x more effective than the S-form.

Chemical formula

C₁₉H₁₇NO₂

Canonical SMILES

CC(C(=O)NC1=CC=CC=C1)OC2=CC3=CC=CC=C3C=C2

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

LVKTWOXHRYGDMM-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C19H17NO2/c1-14(19(21)20-17-9-3-2-4-10-17)22-18-12-11-15-7-5-6-8-16(15)13-18/h2-14H,1H3,(H,20,21)

2D structure diagram/image available?

Yes

General status

Pesticide type

Herbicide

Substance group

Anilide

Minimum active substance purity

Known relevant impurities

Substance origin

Synthetic

Mode of action

Stimulates RNA synthesis. Absorbed through stems and roots. No herbicidal activity itself but is rapidly hydrolysed to an active metabolite

CAS RN

52570-16-8

EC number

CIPAC number

None allocated

US EPA chemical code

PubChem CID

40413

Molecular mass

291.34

PIN (Preferred Identification Name)

rac-(2R)-2-(naphthalen-2-yloxy)-N-phenylpropanamide

IUPAC name

(RS)-α-2-naphthoxypropionanilide

CAS name

2-(2-naphthalenyloxy)-N-phenylpropanamide

Other status information

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 crystalline substance

Formulations

Property

Value

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

Devrinol
Jouster
Naprop

Example products using this active

United Phosphorus
AgriGuard

Formulation and application details

Often supplied as a soluble concentrate that is mixed with water and used as a spray

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

0.75

at 27 °C

Low

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

171000

Acetone

42000

Toluene

17000

Ethanol

Melting point (°C)

128

Boiling point (°C)

Degradation point (°C)

Flashpoint (°C)

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

2.00 X 10⁰³

Calculated

Log P

3.3

High

Bulk density (g ml⁻¹)

1.256

Dissociation constant pKa) at 25 °C

Not applicable

No dissociation

Vapour pressure at 20 °C (mPa)

3.0 X 10^-06

Low volatility

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

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

Surface tension (mN m⁻¹)

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

0.1

Non-persistent

DT₅₀ (lab at 20 °C)

0.1

Non-persistent

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

Substance rapidly degrades to its major metabolite

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

Note

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

Value

Note

Water-sediment DT₅₀ (days)

Water phase only DT₅₀ (days)

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d

Moderately mobile

K_oc

370

Notes and range

Freundlich

K_f

K_foc

¹/_n

Notes and range

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

-1.43

Calculated

Low leachability

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

Value

8.27 X 10^-06

Calculated

Note

Potential for particle bound transport index

Low

Calculated

Potential for loss via drain flow

Moderately mobile

Calculated

Key metabolites

Metabolite

Formation medium

Estimated maximum occurrence fraction

1107/2009 relevancy

2-(2-naphthoxy)propionic acid

Soil

1.00

Not assessed under 91/414 or 1107/2009

ECOTOXICOLOGY

Property

Value

Source; quality score; and other information

Interpretation

Bio-concentration factor

BCF (l kg⁻¹)

CT₅₀ (days)

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 2710

Rat

Low

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)

Birds - Short term dietary (LC₅₀/LD₅₀)

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

Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

3.5

Cyprinus carpio

Moderate

Fish - Chronic 21 day NOEC (mg l⁻¹)

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

Aquatic invertebrates - Chronic 21 day NOEC (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 - Acute 7 day EC₅₀, biomass (mg l⁻¹)

Non-target plants

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

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)

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)

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)

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

Other soil macro-organisms

Acute LC₅₀ (mg kg⁻¹)

Chronic NOEC (mg kg⁻¹)

Other arthropod (1)

LR₅₀ g ha⁻¹

% Effect

Other arthropod (2)

LR₅₀ g ha⁻¹

% Effect

Soil micro-organisms

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)

> 2710

Rat

Low

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

5000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

1.67

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

Exposure Routes

Public

Occupational

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

; ; ; ;

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

No further information available

Handling issues

Property

Value and interpretation

General

When heated to decomposition it emits toxic vapors of NOx

CLP classification 2013

Health: H313

EC Risk Classification

EC Safety Classification

WHO Classification

III (Slightly hazardous)

UN Number

Waste disposal & packaging

TRANSLATIONS

Language

Name

English

naproanilide

French

German

Danish

Italian

Spanish

Greek

Polish

Swedish

Hungarian

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