Hexazinone (Ref: DPX A3674)

Hexazinone (Ref: DPX A3674)	Last updated: 23/08/2024
(Also known as: DPX-3674)

SUMMARY

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: GUS: High leachability; Drainflow: Mobile	Ecotoxicity Moderate alert: Fish chronic ecotoxicity: Moderate; Daphnia acute ecotoxicity: Moderate; Bees acute unknown ecotoxicity: Moderate	Human health Moderate alert: Mammals acute toxicity: Moderate; Reproduction/development effects

GENERAL INFORMATION

Description

A broad-spectrum herbicide used to control many annual, biennial and perennial weeds.

Example pests controlled

Grasses; Broad-leaved weeds; Woody plants

Example applications

Fruit; Sugarcane; Alfalfa; Forestry; Pastures; Rangeland; Fallow land

Efficacy & activity

Availability status

Current

Introduction & key dates

1975, registered USA

UK regulatory status

UK COPR regulatory status

Not approved

Date COPR inclusion expires

Expired

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

Date EC 1107/2009 inclusion expires

Expired

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

Australia

Chemical structure

Isomerism

None

Chemical formula

C₁₂H₂₀N₄O₂

Canonical SMILES

CN1C(=NC(=O)N(C1=O)C2CCCCC2)N(C)C

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

CAWXEEYDBZRFPE-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C12H20N4O2/c1-14(2)10-13-11(17)16(12(18)15(10)3)9-7-5-4-6-8-9/h9H,4-8H2,1-3H3

2D structure diagram/image available?

Yes

General status

Pesticide type

Herbicide

Substance groups

Triazinone herbicide

Minimum active substance purity

Known relevant impurities

Substance origin

Synthetic

Mode of action

Non-selective with contact action, absorbed through the roots and foliage of plants. Inhibits photosynthesis (photosystem II).

CAS RN

51235-04-2

EC number

257-074-4

CIPAC number

374

US EPA chemical code

107201

PubChem CID

39965

CLP index number

613-132-00-4

Molecular mass

252.31

PIN (Preferred Identification Name)

IUPAC name

3-cyclohexyl-6-dimethylamino-1-methyl-1,3,5-triazine-2,4(1H,3H)-dione

CAS name

3-cyclohexyl-6-(dimethylamino)-1-methyl-1,3,5-triazine-2,4(1H,3H)-dione

Other status information

Potential groundwater contaminant; Chemical subject to PIC regulations

Relevant Environmental Water Quality Standards

Herbicide Resistance Class (HRAC MoA class)

Herbicide Resistance Class (WSSA MoA class)

Insecticide Resistance Class (IRAC MoA class)

Not applicable

Fungicide Resistance Class (FRAC MOA class)

Not applicable

Examples of recorded resistance

Physical state

Colourless crystals

Formulations

Property

Value

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

DuPont
AgroCare
Makhteshim Agan Group
FCC Ltd

Example products using this active

Velpar Weed Killer
Pronone
Fertihexa
Elinone

Formulation and application details

Available in a variety of formulations including wettable granules, suspension concentrates and tablets

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

33000

High

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

626000

Acetone

334000

Toluene

2146500

Methanol

837000

Benzene

Melting point (°C)

113.5

Boiling point (°C)

Decomposes on distillation

Degradation point (°C)

Flashpoint (°C)

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

1.48 X 10⁰¹

Calculated

Log P

1.17

Low

Fat solubility of residues

Solubility

Data type

Density (g ml⁻¹)

1.25

Dissociation constant pKa) at 25 °C

2.2

Weak base

Vapour pressure at 20 °C (mPa)

0.03

Low volatility

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

1.10 X 10^-07

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)

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Soil degradation (days) (aerobic)

DT₅₀ (typical)

105

Persistent

DT₅₀ (lab at 20 °C)

Moderately persistent

DT₅₀ (field)

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

Other sources: DT₅₀ 30 (sand) - 180 (clay) days (R3); General literature DT₅₀ range 59-64 days (R3)

Dissipation rate RL₅₀ (days) on plant matrix

Value

Note

Dissipation rate RL₅₀ (days) on and in plant matrix

Value

11.3

Note

Published literature RL₅₀ range 10.5-12.0 days, 2 field crops, various matrices, n=2

Aqueous photolysis DT₅₀ (days) at pH 7

Value

Stable

Note

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

Value

Moderately persistent

Note

Water-sediment DT₅₀ (days)

Water 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

Other sources: K_oc 610 (P3)

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

4.43

Calculated

High leachability

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

Value

2.15 X 10⁰⁰

Calculated

Note

Potential for particle bound transport index

Medium

Calculated

Potential for loss via drain flow

Mobile

Calculated

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

Bio-concentration factor

BCF (l kg⁻¹)

Low potential

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

3-(4-hydroxycyclohexyl)-6-(dimethylamino)-1-methyl-1,3,5-triazine-2,4(1H,3H)dione

3-cyclohexyl-6-(methylamino)-1-methyl-1,3,5-triazine-2,4-(1H,3H)-dione

Major fraction

3-(4-hydroxycyclohexyl)-6-(methylamino)-1-methyl-1,3,5-triazine-2,4(1H,3H)-dione

Major fraction

Known groundwater metabolites

None

Other known metabolites

None

ECOTOXICOLOGY

Terrestrial ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

1690

Rat

Moderate

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)

> 2258

Colinus virginianus

Low

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)

> 100

Apis mellifera

Low

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)

Moderate

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)

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)

> 320

Oncorhynchus mykiss

Low

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

0.0855

Salmo salar

Moderate

Tropical Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

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

> 85

Daphnia magna

Moderate

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

> 50

Daphnia magna LOEC

Low

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

> 0.55

Ceriodaphnia dubia LC₅₀

Moderate

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)

> 0.072

Lemna minor 7 day

Moderate

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

0.0145

Pseudokirchneriella subcapitata

Moderate

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)

1690

Rat

Moderate

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

5000

Rabbit

Mammals - Inhalation LC₅₀ (mg l⁻¹)

7.48

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

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

; ; ; ;

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

Highly toxic

Handling issues

Property

Value and interpretation

General

No information available

CLP classification 2013

Health: H302, H319
Environment: H400, H410

WHO Classification

II (Moderately hazardous)

UN Number

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

hexazinone

French

hexazinone

German

Hexazinon

Danish

hexazinon

Italian

esazinone

Spanish

hexazinona

Greek

Polish

heksazynon

Swedish

Hungarian

hexazinone

Dutch

Norwegian

Record last updated:	23/08/2024
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