Simazine (Ref: G 27692)	Last updated: 11/03/2021
(Also known as: permazine ; symazine; taphazine)

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GENERAL INFORMATION

Description	A soil-acting herbicide with used to control most germinating annual grasses and broad-leaved weeds. Has also been used to control algae in ponds and fish hatcheries.
Example pests controlled	Ivyleaved speedwell; Rocket; Shepherd's purse; Dead nettles; Goosefoot; Bindweed; Suppresses volunteer cereals
Example applications	Fruit including berries, currants, apples, pears; Hops; Almonds; Vines; Canola; Chickpeas; Beans; Lupins
Efficacy & activity	-
Availability status	Current
Introduction & key dates	circa 1960

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	UK
Date EC 1107/2009 inclusion expires	Not applicable
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	Australia, USA

Chemical structure

Isomerism	-
Chemical formula	C₇H₁₂ClN₅
Canonical SMILES	CCNC1=NC(=NC(=N1)Cl)NCC
Isomeric SMILES	No data
International Chemical Identifier key (InChIKey)	ODCWYMIRDDJXKW-UHFFFAOYSA-N
International Chemical Identifier (InChI)	InChI=1S/C7H12ClN5/c1-3-9-6-11-5(8)12-7(13-6)10-4-2/h3-4H2,1-2H3,(H2,9,10,11,12,13)
2D structure diagram/image available?	Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
simazine	-

General status

Pesticide type	Herbicide
Substance group	Triazine
Minimum active substance purity	-
Known relevant impurities	-
Substance origin	Synthetic
Mode of action	Selective, systemic, absorbed through roots and foliage and translocated. Inhibits photosynthesis (photosystem II).
CAS RN	122-34-9
EC number	204-535-2
CIPAC number	22
US EPA chemical code	080807
PubChem CID	5216
Molecular mass	201.66
PIN (Preferred Identification Name)	6-chloro-N2,N4-diethyl-1,3,5-triazine-2,4-diamine
IUPAC name	6-chloro-N2,N4-diethyl-1,3,5-triazine-2,4-diamine
CAS name	6-chloro-N,N'-diethyl-1,3,5-triazine-2,4-diamine
Other status information	WFD priority substance; Potential groundwater and surface water contaminant; Chemical subject to PIC regulations
Relevant Environmental Water Quality Standards	EU Directive 2008/105/EC EQS surface waters: annual average 1.0 µg l⁻¹; max measured 4.0 µg l⁻¹ UK stutory standard for the protection of aquatic life: freshwater and salt water annual average 2 µg l⁻¹
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	Amaranthus albus, Amaranthus blitoides
Physical state	Colourless to white solid

Formulations

Property	Value
Example manufacturers & suppliers of products using this active now or historically	Sanazine Simanex Amizina Eagrow Derby
Example products using this active	Loveland Chemicals Makhteshim Agan Syngenta
Formulation and application details	Available in a range of formulations including wettable powders, water dispersible granules, liquids and granules.

ENVIRONMENTAL FATE

Property		Value	Source; quality score; and other information	Interpretation
Solubility - In water at 20 °C (mg l⁻¹)		5	B5 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 5 = Verified data used for regulatory purposes	Low
Solubility - In organic solvents at 20 °C (mg l⁻¹)		570	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Ethanol	-
		1500	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Acetone	-
		130	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Toluene	-
		3.1	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source n-Hexane	-
Melting point (°C)		Decomposes before melting	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	-
Boiling point (°C)		Decomposes before boiling	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	-
Degradation point (°C)		226	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	-
Flashpoint (°C)		Not expected to self ignite; Not highly flammable	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	-
Octanol-water partition coefficient at pH 7, 20 °C	P	2.00 X 1002	Calculated	-
	Log P	2.3	B5 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 5 = Verified data used for regulatory purposes	Low
Bulk density (g ml⁻¹)		1.3	B5 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 5 = Verified data used for regulatory purposes	-
Dissociation constant pKa) at 25 °C		1.62	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	-
		Very weak base
Vapour pressure at 20 °C (mPa)		0.00081	B5 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 5 = Verified data used for regulatory purposes	Low volatility
Henry's law constant at 25 °C (Pa m³ mol⁻¹)		5.60 X 10-05	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	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)	60	DW4 DW = Don Wauchope personal database for Pka data: Wauchope, R. D. and Edwards, J. Dissociation constants for pesticide active ingredients: a database and comparison with predicted values. MS in preparation 4 = Verified data	Moderately persistent
	DT₅₀ (lab at 20 °C)	-	-	-
	DT₅₀ (field)	90	B4 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 4 = Verified data	Moderately persistent
	DT₉₀ (lab at 20 °C)	-	-	-
	DT₉₀ (field)	-	-	-
	DT₅₀ modelling endpoint	-	-	-
	Note	Other sources: DT₅₀ 27-102 days (R3), 91 days at 25 °C (R4)
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	1.9	K4 K = Research datasets, e.g. Pandora, Demetra 4 = Verified data	Moderately fast
	Note	Unstable in UV light
Aqueous hydrolysis DT₅₀ (days) at 20 °C and pH 7	Value	96	B4 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 4 = Verified data	Moderately persistent
	Note	Stable under normal environmental conditions, hydrolysis does occur in strong acid and alkai solutions
Water-sediment DT₅₀ (days)		33	Q2 Q = Miscellaneous internet resources 2 = Unverified data of unknown source	Moderately fast
Water phase only DT₅₀ (days)		46	K4 K = Research datasets, e.g. Pandora, Demetra 4 = Verified data	Stable

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	Moderately mobile
	Koc	130
	Notes and range	Other sources: Log Koc 2.14 at 25 °C (R3), 2.11 (R3)
Freundlich	Kf	15.88	R4 R = Peer reviewed scientific publications 4 = Verified data	Slightly mobile
	Kfoc	750
	1/n	0.76
	Notes and range	Kf range 4.59-20.6 mL g⁻¹, Kfoc range 124-1585 mL g⁻¹, 1/n range 0.33-0.89, Soils=3
pH sensitivity		-

Fate indices

Property		Value	Source; quality score; and other information	Interpretation
GUS leaching potential index		2.20	Calculated	Transition state
SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate	Value	1.07 X 10-01	Calculated	-
	Note	-
Potential for particle bound transport index		Medium	Calculated	-
Potential for loss via drain flow		Moderately mobile	Calculated	-

Key metabolites

Metabolite	Formation medium	Estimated maximum occurrence fraction	1107/2009 relevancy
6-deisopropyl atrazine (Ref: G-28279)	Soil	-	-
2-hydroxy-4,6-bis(ethlyamino)-S-triazine	Soil	-	-

ECOTOXICOLOGY

Property		Value	Source; quality score; and other information	Interpretation
Bio-concentration factor	BCF (l kg⁻¹)	221	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	Threshold for concern
	CT₅₀ (days)	Not available		-
Mammals - Acute oral LD₅₀ (mg kg⁻¹)		> 5000	B4 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 4 = Verified data Rat	Low
Mammals - Short term dietary NOEL	(mg kg⁻¹)	6.9	B5 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 5 = Verified data used for regulatory purposes Rat	High
	(ppm diet)	200		-
Mammals - Chronic 21d NOAEL (mg kg⁻¹ bw d⁻¹)		-	-	-
Birds - Acute LD₅₀ (mg kg⁻¹)		4640	B5 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 5 = Verified data used for regulatory purposes Anas platyrhynchos	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)		90	B5 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 5 = Verified data used for regulatory purposes Lepomis macrochirus	Moderate
Fish - Chronic 21 day NOEC (mg l⁻¹)		0.7	P3 P = Other governments and regulators 3 = Unverified data of known source Unknown species	Moderate
Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)		1.1	B5 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 5 = Verified data used for regulatory purposes Daphnia magna	Moderate
Aquatic invertebrates - Chronic 21 day NOEC (mg l⁻¹)		2.5	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	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)		0.3	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 Lemna gibba	Moderate
Non-target plants		-	-	-
		-	-	-
Algae - Acute 72 hour EC₅₀, growth (mg l⁻¹)		0.04	B5 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 5 = Verified data used for regulatory purposes Scenedemus subspicatus	Moderate
Algae - Chronic 96 hour NOEC, growth (mg l⁻¹)		0.6	Q2 Q = Miscellaneous internet resources 2 = Unverified data of unknown source Unknown species	Moderate
Honeybees (Apis spp.)	Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	97	B3 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 3 = Unverified data of known source	Moderate
	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)		1000	B5 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 5 = Verified data used for regulatory purposes Eisenia foetida	Moderate
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	Harmless	[Dose: 1125 g ha⁻¹] AA3 AA = IOBC Database on classification of side effects to beneficial organisms, 2005 3 = Unverified data of known source Typhlodromus pyri	-
Other arthropod (2)	LR₅₀ g ha⁻¹	-	-	-
	% Effect	Harmless	[Dose: 1125 g ha⁻¹] AA3 AA = IOBC Database on classification of side effects to beneficial organisms, 2005 3 = Unverified data of known source Chrysoperla carnea	-
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)		> 5000	B4 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 4 = Verified data Rat	Low
Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)		2000	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source Rat	-
Mammals - Inhalation LC₅₀ (mg l⁻¹)		5.5	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)		0.005	B4 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 4 = Verified data UK ACP 1999	-
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)		0.05	B4 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 4 = Verified data UK ACP 1999	-
Dermal penetration studies (%)		-	-	-
Dangerous Substances Directive 76/464		List II	-	-
Exposure Routes	Public	-
	Occupational	-
MRLs	European	EU MRL pesticide database
	Notes	-
Drinking Water Standards		Non-statutory WHO drinking water guideline 0.002 mg l⁻¹	B5 B = UK CRD and ACP evaluation documents / and other Defra (UK) documents (click here ) 5 = Verified data used for regulatory purposes UK EA QS database 2018	-
Drinking Water MAC (μg l⁻¹)		-	-	-

Health issues

Specific human health issues		Carcinogen Genotoxic Endocrine disruptor ?Possibly, status not identified A3 A = Chromosome aberration (EFSA database) 3 = Negative ; B3 B = DNA damage/repair (EFSA database) 3 = Negative ; C3 C = Gene mutation (EFSA database) 3 = Negative ; D0 D = Genome mutation (EFSA database) 0 = No data ; E3 E = Unspecified genotoxicity type (miscellaneous data source) 3 = Negative ?Possibly, status not identified Reproduction / development effects Acetyl cholinesterase inhibitor Neurotoxicant ?Possibly, status not identified No data found No data found Respiratory tract irritant Skin irritant Skin sensitiser XNo, known not to cause a problem ?Possibly, status not identified No data found Eye irritant Phototoxicant   ?Possibly, status not identified No data found
General human health issues		May cause dermatitis May cause tremor, convulsions, paralysis, cyanosis, slowed respiration and diarrhea Endocrine issues - Induction of aromatase activity, increase of estrogen production

Handling issues

Property	Value and interpretation
General	Prevent generation of dust IMDG Transport Code is usually 9
CLP classification 2013	Health: H351 Environment: H400, H410
EC Risk Classification	Carcinogen category 3: R40 N - Dangerous for the environment: R50, R53
EC Safety Classification	S2, S36/37, S46, S60, S61
WHO Classification	U (Unlikely to present an acute hazard)
UN Number	Usually 3077
Waste disposal & packaging	Packaging Group III (minor danger)

TRANSLATIONS

Language	Name
English	simazine
French	simazine
German	Simazin
Danish	simazin
Italian	simazina
Spanish	simazina
Greek	simazine
Polish	symazyna
Swedish	-
Hungarian	-
Dutch	simazine

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Record last updated:	11/03/2021
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