1-naphthylacetamide

1-naphthylacetamide	Last updated: 16/03/2024
(Also known as: 1-NAD; alpha-naphthylacetamide; alpha-NAA amide)

SUMMARY

1-naphthylacetamide is a synthetic auxin plant growth regulator used to increase fruit yield, increase fruit thinning and for striking cuttings. It is moderately soluble in water, has a low volatility and tends not to be persistent in soil or aquatic systems. The risk of leaching to groundwater is low. It has a low to moderate toxicity to biodiversity. 1-naphthylacetamide has a moderate oral toxicity to mammals and is a reproduction/developmental toxin.

Data alerts

The following alerts are based on the data in the tables below. An absence of an alert does not imply the substance has no implications for human health, biodiversity or the environment but just that we do not have the data to form a judgement.

Environmental fate	Ecotoxicity	Human health
Environmental fate High alert: Drainflow: Mobile	Ecotoxicity Moderate alert: Fish acute ecotoxicity: Moderate; Daphnia acute ecotoxicity: Moderate	Human health Moderate alert: Mammals acute toxicity: Moderate; Reproduction/development effects

GENERAL INFORMATION

Description

A synthetic auxin plant growth regulator used to increase fruit yield, increase fruit thining and for striking cuttings.

Example pests controlled

Pre-harvest drop; Cutting success

Example applications

Fruit including apples, pears, grape, guavas; Tomato; Zuccini; Soft & hardwood cuttings

Efficacy & activity

Availability status

Current

Introduction & key dates

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

Hungary/France

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
			✓	✓			✓

Approved for use (✓) under EC 1107/2009 by Mutual Recognition of Authorisation and/or national regulations in the following EEA countries

ISIceland	NONorway

Additional information

Also used in

Chemical structure

Isomerism

None

Chemical formula

C₁₂H₁₁NO

Canonical SMILES

C1=CC=C2C(=C1)C=CC=C2CC(=O)N

Isomeric SMILES

International Chemical Identifier key (InChIKey)

XFNJVKMNNVCYEK-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C12H11NO/c13-12(14)8-10-6-3-5-9-4-1-2-7-11(9)10/h1-7H,8H2,(H2,13,14)

2D structure diagram/image available?

Yes

General status

Pesticide type

Plant Growth Regulator

Substance groups

Auxin PGR; Naphthalene compound

Minimum active substance purity

980 g kg⁻¹

Known relevant impurities

EU dossier - none declared

Substance origin

Synthetic

Mode of action

Absorbed through roots, stems and leaves, demonstrates auxin-like activity

CAS RN

86-86-2

EC number

201-704-2

CIPAC number

282

US EPA chemical code

056001

PubChem CID

6861

CLP index number

No data found

Molecular mass

185.2

PIN (Preferred Identification Name)

IUPAC name

2-(1-naphthyl)acetamide

CAS name

1-naphthylacetamide

Other status information

Relevant Environmental Water Quality Standards

Herbicide Resistance Class (HRAC MoA class)

Not applicable

Herbicide Resistance Class (WSSA MoA class)

Not applicable

Insecticide Resistance Class (IRAC MoA class)

Not applicable

Fungicide Resistance Class (FRAC MOA class)

Not applicable

Examples of recorded resistance

Physical state

Off-white coloured powder

Formulations

Property

Value

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

AMIVAC
Nufarm

Example products using this active

Amid-thin W
Amcotone
Rootone

Formulation and application details

Usually supplied as a wettable powder

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

170

Moderate

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

250000

Methanol

250000

Acetone

1000

Xylene

1000

n-Heptane

Melting point (°C)

180

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

180

Flashpoint (°C)

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

3.80 X 10⁰¹

Calculated

Log P

1.58

Low

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

Dissociation constant pKa) at 25 °C

0.41

Vapour pressure at 20 °C (mPa)

9.40 X 10^-04

Low volatility

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

1.02 X 10^-08

Non-volatile

Volatilisation as max % of applied dose lost

From plant surface

From soil surface

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

Acidic solution: 224nm = 78200, 271nm = 6190, 281nm = 7350
Neutral solution: 224nm = 79000, 271nm = 6140, 281nm = 7280
Basic solution: 271nm = 6160, 281nm = 7290

Surface tension (mN m⁻¹)

71.4

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

0.52

Non-persistent

DT₅₀ (lab at 20 °C)

0.29

Non-persistent

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

0.95

Non-persistent

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

EU dossier DT₅₀ range 0.06 days (sandy loam) - 0.52 days (humic-sand), DT₉₀ range 0.19-1.7; Other data Lab studies DT₅₀ range 0.39 (range of soils) - 301.3 (Japanese sterile soil) days, DT₉₀ range 1.29 (range of soils) - 1001.1 (Japanese sterile soil)

Dissipation rate RL₅₀ (days) on plant matrix

Value

Note

Dissipation rate RL₅₀ (days) on and in plant matrix

Value

Note

Aqueous photolysis DT₅₀ (days) at pH 7

Value

4.7

Moderately fast

Note

Irradiated sample

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

Value

Stable

Note

Stable pH 4, 7 and 9

Water-sediment DT₅₀ (days)

Water phase only DT₅₀ (days)

3.7

Moderately fast

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.

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d

1.39

Mobile

K_oc

Notes and range

EU dossier K_oc estimated

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

-1.45

Calculated

Low leachability

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

Value

3.87 X 10^-04

Calculated

Note

Potential for particle bound transport index

Low

Calculated

Potential for loss via drain flow

Mobile

Calculated

Photochemical oxidative DT₅₀ (hrs) as indicator of long-range air transport risk

4.56

Calculated using the Atkinson method. Assumed 1.5E+06 OH/cm³, 12 hr

Below the level of concern for long-range air transport

Bio-concentration factor

BCF (l kg⁻¹)

Low risk

Based on LogP < 3

Low risk

CT₅₀ (days)

Known soil metabolites

Metabolite

Major/Minor fraction

$Click here for further information on Major/Minor fraction$

Estimated maximum occurrence fraction

Notes

1-naphthylacetic acid

Major fraction

0.739

1-naphthoic acid

Major fraction

0.224

Known groundwater metabolites

Metabolite

EC SANCO/221/2000 relevancy

ADI (mg kg⁻¹ bodyweight day⁻¹)

WHO drinking water guidance value (μg L⁻¹ day⁻¹)

1-naphthylacetic acid

Not relevant

Other known metabolites

None

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

1655

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)

> 2000

Coturnix japonica

Low

Birds - Short term dietary (LC₅₀/LD₅₀)

> 5620 mg kg feed⁻¹

Coturnix japonica

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

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

> 1000

Eisenia foetida

Low

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

Soil micro-organisms

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

Dose = 0.107 mg kg⁻¹ soil 28 Day

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)

> 100

Apis mellifera

Low

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

> 138.7

Apis mellifera

Low

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

Chronic

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) as % Mortality at diose 440 g l⁻¹

Coccinella septempunctata Dipped Larva

Beneficial insects (Lacewings)

Beneficial insects (Parasitic wasps) as Mortality LR₅₀ g ha⁻¹

> 40.0

Aphidius rhopalosiphi

Beneficial insects (Predatory mites) as Mortality LR₅₀ g ha⁻¹

> 40.0

Typhlodromus pyri

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)

44.0

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)

> 56

Daphnia magna

Moderate

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 - Acute 7 day EC₅₀, biomass (mg l⁻¹)

7.4

Lemna minor

Moderate

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

> 100

Desmodesmus subspicatus Biomass

Low

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

1655

Rat

Moderate

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

2000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 2.17

Rat (whole body)

Other Mammal toxicity endpoints

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

0.10

Rat SF=150

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

0.10

Rat SF=150

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

None allocated

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

0.07

Rat SF=150

Dermal penetration studies (%)

1-21

concentration dependent

Dangerous Substances Directive 76/464

Exposure Routes

Public

No unacceptable risks identified

Occupational

PPE/PPC advised to mitigate exposure risks

MRLs

European

EU MRL pesticide database

Great Britain

GB MRL Register

Notes

Drinking Water Standards

Drinking Water MAC (μg l⁻¹)

Mammalian dose elimination route and rate

Health issues

Specific human health issues

Carcinogen

Genotoxic

Endocrine disruptor

; ; ; ;

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

Liver and kidney toxicant

Handling issues

Property

Value and interpretation

General

Not explosive or oxidising
Not expected to auto-ignite; Not highly flammable

CLP classification 2013

Health: H302, H318, H361
Environment: H412

WHO Classification

U (Unlikely to present an acute hazard)

UN Number

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

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Name

English

1-naphthylacetamide

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Record last updated:	16/03/2024
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