Hexazinone (Ref: DPX A3674)	Last updated: 09/02/2021
(Also known as: DPX-3674)

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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, 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

Also used in

Also used in	-

Chemical structure

Isomerism	-
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 group	Triazinone
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
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 Classification (HRAC)	C1
Herbicide Resistance Classification (WSSA)	5
Insecticide Resistance Classification (IRAC)	Not applicable
Fungicide Resistance Classification (FRAC)	Not applicable
Examples of recorded resistance	-
Physical state	Colourless crystals
Related substances & organisms	diuron sulfometuron-methyl

Formulations

Property	Value
Example manufacturers & suppliers of products using this active now or historically	Velpar Weed Killer Pronone Fertihexa Elinone
Example products using this active	DuPont AgroCare Makhteshim Agan Group FCC Ltd
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	K4 K = Research datasets, e.g. Pandora, Demetra 4 = Verified data	High
Solubility - In organic solvents at 20 °C (mg l⁻¹)		626000	C4 C = AGRITOX (click here ) 4 = Verified data Acetone	-
		334000	C4 C = AGRITOX (click here ) 4 = Verified data Toluene	-
		2146500	C4 C = AGRITOX (click here ) 4 = Verified data Methanol	-
		837000	C4 C = AGRITOX (click here ) 4 = Verified data Benzene	-
Melting point (°C)		113.5	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	-
Boiling point (°C)		Decomposes on distillation	L2 L = Pesticide manuals and hard copy reference books / other sources 2 = Unverified data of unknown source	-
Degradation point (°C)		-	-	-
Flashpoint (°C)		-	-	-
Octanol-water partition coefficient at pH 7, 20 °C	P	1.48 X 1001	Calculated	-
	Log P	1.17	P4 P = Other governments and regulators 4 = Verified data	Low
Bulk density (g ml⁻¹)		1.25	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	-
Dissociation constant pKa) at 25 °C		2.2	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	-
		Weak base
Vapour pressure at 20 °C (mPa)		0.03	G4 G = Extension Toxicology network database EXTOXNET (click here ) 4 = Verified data	Low volatility
Henry's law constant at 25 °C (Pa m³ mol⁻¹)		1.10 X 10-07	H4 H = The US ARS pesticide properties database (click here ) 4 = Verified data	Non-volatile
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	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	Persistent
	DT₅₀ (lab at 20 °C)	90	F3 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents (US EPA Databases Related to Pesticide Risk Assessment ) 3 = Unverified data of known source	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 on plant matrix	Value	-	-	-
	Note	-
Dissipation rate RL₅₀ on and in plant matrix	Value	11.3	R4 R = Peer reviewed scientific publications 4 = Verified data	-
	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	56	K4 K = Research datasets, e.g. Pandora, Demetra 4 = Verified data	Stable
	Note	-
Aqueous hydrolysis DT₅₀ (days) at 20 °C and pH 7	Value	56	K4 K = Research datasets, e.g. Pandora, Demetra 4 = Verified data	Moderately persistent
	Note	-
Water-sediment DT₅₀ (days)		-	-	-
Water phase only DT₅₀ (days)		-	-	-

Soil adsorption and mobility

Property		Value	Source; quality score; and other information	Interpretation
Linear	Kd	-	G3 G = Extension Toxicology network database EXTOXNET (click here ) 3 = Unverified data of known source	Mobile
	Koc	54
	Notes and range	Other sources: Koc 610 (P3)
Freundlich	Kf	-	-	-
	Kfoc	-
	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	-

Key metabolites

Metabolite	Formation medium	Estimated maximum occurrence fraction	1107/2009 relevancy
3-(4-hydroxycyclohexyl)-6-(dimethylamino)-1-methyl-1,3,5-triazine-2,4(1H,3H)dione	Soil	-	-
3-cyclohexyl-6-(methylamino)-1-methyl-1,3,5-triazine-2,4-(1H,3H)-dione	Soil	-	Major
3-(4-hydroxycyclohexyl)-6-(methylamino)-1-methyl-1,3,5-triazine-2,4(1H,3H)-dione	Soil	-	Major

ECOTOXICOLOGY

Property		Value	Source; quality score; and other information	Interpretation
Bio-concentration factor	BCF (l kg⁻¹)	7	P4 P = Other governments and regulators 4 = Verified data	Low potential
	CT₅₀ (days)	Not available		-
Mammals - Acute oral LD₅₀ (mg kg⁻¹)		1690	G4 G = Extension Toxicology network database EXTOXNET (click here ) 4 = Verified data Rat	Moderate
Mammals - Short term dietary NOEL	(mg kg⁻¹)	-	L2 L = Pesticide manuals and hard copy reference books / other sources 2 = Unverified data of unknown source Rat 2 year	-
	(ppm diet)	> 200		-
Mammals - Chronic 21d NOAEL (mg kg⁻¹ bw d⁻¹)		-	-	-
Birds - Acute LD₅₀ (mg kg⁻¹)		> 2258	G4 G = Extension Toxicology network database EXTOXNET (click here ) 4 = Verified data Colinus virginianus	Low
Birds - Short term dietary (LC₅₀/LD₅₀)		-	-	-
Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)		-	-	-
Fish - Acute 96 hour LC₅₀ (mg l⁻¹)		> 320	G4 G = Extension Toxicology network database EXTOXNET (click here ) 4 = Verified data Oncorhynchus mykiss	Low
Fish - Chronic 21 day NOEC (mg l⁻¹)		0.0855	P3 P = Other governments and regulators 3 = Unverified data of known source Salmo salar	Moderate
Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)		> 85	J4 J = Pesticide Action Network database (click here ) 4 = Verified data Daphnia magna	Moderate
Aquatic invertebrates - Chronic 21 day NOEC (mg l⁻¹)		> 50	F3 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents (US EPA Databases Related to Pesticide Risk Assessment ) 3 = Unverified data of known source Daphnia magna LOEC	Low
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	F2 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents (US EPA Databases Related to Pesticide Risk Assessment ) 2 = Unverified data of unknown source Lemna minor 7 day	Moderate
Non-target plants		-	-	-
		-	-	-
Algae - Acute 72 hour EC₅₀, growth (mg l⁻¹)		0.0145	F4 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents (US EPA Databases Related to Pesticide Risk Assessment ) 4 = Verified data 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	F4 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents (US EPA Databases Related to Pesticide Risk Assessment ) 4 = Verified data 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)	60	L2 L = Pesticide manuals and hard copy reference books / other sources 2 = Unverified data of unknown source	Moderate
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	-	-	-
	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	G4 G = Extension Toxicology network database EXTOXNET (click here ) 4 = Verified data Rat	Moderate
Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)		5000	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Rabbit	-
Mammals - Inhalation LC₅₀ (mg l⁻¹)		7.48	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Rat	-
Other Mammal toxicity endpoints		-	-	-
ADI - Acceptable Daily Intake (mg kg⁻¹ bw day⁻¹)		0.05	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	-
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 XNo, known not to cause a problem A3 A = Chromosome aberration (EFSA database) 3 = Negative ; B0 B = DNA damage/repair (EFSA database) 0 = No data ; C0 C = Gene mutation (EFSA database) 0 = No data ; D0 D = Genome mutation (EFSA database) 0 = No data ; E3 E = Unspecified genotoxicity type (miscellaneous data source) 3 = Negative No data found Reproduction / development effects Acetyl cholinesterase inhibitor Neurotoxicant ?Possibly, status not identified XNo, known not to cause a problem XNo, known not to cause a problem Respiratory tract irritant Skin irritant Skin sensitiser No data found ✓Yes, known to cause a problem No data found Eye irritant Phototoxicant   ✓Yes, known to cause a problem 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
EC Risk Classification	Xn - Harmful: R22 Xi - Irritant: R36 N - Dangerous for the environment: R50, R53
EC Safety Classification	S2, S60, S61
WHO Classification	II (Moderately hazardous)
UN Number	-
Waste disposal & packaging	-

TRANSLATIONS

Language	Name
English	hexazinone
French	hexazinone
German	Hexazinon
Danish	hexazinon
Italian	esazinone
Spanish	hexazinona
Greek	-
Polish	heksazynon
Swedish	-
Hungarian	hexazinone
Dutch	-

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Record last updated:	09/02/2021
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