Atrazine (Ref: G 30027)

Atrazine (Ref: G 30027)	Last updated: 12/10/2023
(Also known as: aneldazin)

SUMMARY

Atrazine is a herbicide used to control broad-leaved weeds and grasses. It has selective, systemic action with residual and foliar activity. It has a low aqueous solubility, it is volatile and, based on its physico-chemical properties there is some concern that it could leach to groundwater. It is generally not persistent in the field nor in aquatic systems. It is moderately toxic to mammals, is not expected to bioaccumulate and is a skin, eye and respiratory system irritant. Atrazine is moderately toxic to most aquatic life, earthworms and honeybees but presents less of a risk to birds.

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 Moderate alert: GUS: Transition state; Drainflow: Moderately mobile	Ecotoxicity Moderate alert: Fish acute ecotoxicity: Moderate; Fish chronic ecotoxicity: Moderate; Daphnia acute ecotoxicity: Moderate; Daphnia chronic ecotoxicity: Moderate; Earthworms acute ecotoxicity: Moderate	Human health High alert: Endocrine disrupter

GENERAL INFORMATION

Description

A triazine herbicide used pre- and post-emergence with restricted permitted uses to control broad-leaved weeds and grasses

Example pests controlled

Morning glory; Barnyard grass; Cocklebur; Lambsquarters; Crabgrass; Pigweed; Buckwheat; Ragweed; Foxtail

Example applications

Corn; Sorghum; Sugarcane; Turf; Asparagus

Efficacy & activity

Availability status

Current

Introduction & key dates

1957

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)

Not applicable

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, USA

Chemical structure

Isomerism

None

Chemical formula

C₈H₁₄ClN₅

Canonical SMILES

CCNC1=NC(=NC(=N1)Cl)NC(C)C

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

MXWJVTOOROXGIU-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C8H14ClN5/c1-4-10-7-12-6(9)13-8(14-7)11-5(2)3/h5H,4H2,1-3H3,(H2,10,11,12,13,14)

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
atrazine	-

General status

Pesticide type

Herbicide

Substance groups

Triazine herbicide; Chlorotriazine herbicide

Minimum active substance purity

Known relevant impurities

Substance origin

Synthetic

Mode of action

Selective, systemic action with residual and foliar activity. Inhibits photosynthesis (photosystem II).

CAS RN

1912-24-9

EC number

217-617-8

CIPAC number

US EPA chemical code

080803

PubChem CID

2256

CLP index number

613-068-00-7

Molecular mass

215.68

PIN (Preferred Identification Name)

6-chloro-N2-ethyl-N4-(propan-2-yl)-1,3,5-triazine-2,4-diamine

IUPAC name

6-chloro-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine

CAS name

6-chloro-N-ethyl-N'-(1-methylethyl)-1,3,5-triazine-2,4-diamine

Other status information

OSPAR soc; WFD priority substance; Potential groundwater contaminant; Chemical subject to PIC regulations; PAN Bad Actor Chemical

Relevant Environmental Water Quality Standards

EU Directive 2008/105/EC EQS surface waters: annual average 0.6 µg l⁻¹; max measured 2.0 µg l⁻¹
UK statutory standard for protection of aquatic life for inland, coastal and territory surface waters 2.0 µg l⁻¹

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

Many recorded cases, Alopecurus myosuroides, Alopecurus myosuroides, Amaranthus retroflexus, Conyza canadensis, Abutilon theophrasti

Physical state

White crystals

Formulations

Property

Value

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

Syngenta
Bayer CropScience
Monsanto
Scotts

Example products using this active

Gesaprim
Fenamin
Atrazinax
Weedex
Primaze
Atratol
Radazine
Aatrex

Formulation and application details

Available in a variety of formulations including dry flowable, flowable liquid, liquid, water dispersible granules and wettable powders.

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

Low

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

24000

Ethyl acetate

28000

Dichloromethane

4000

Toluene

110

n-Hexane

Melting point (°C)

175.8

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

Flashpoint (°C)

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

5.01 X 10⁰²

Calculated

Log P

2.7

Moderate

Fat solubility of residues

Solubility

Soluble

Data type

Regulatory data - observed in metabolism and farm animal feeding studies

Density (g ml⁻¹)

1.23

Dissociation constant pKa) at 25 °C

1.7

Very weak base

Vapour pressure at 20 °C (mPa)

0.039

Low volatility

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

1.50 X 10^-04

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)

Laboratory

Moderately persistent

DT₅₀ (lab at 20 °C)

Moderately persistent

DT₅₀ (field)

Non-persistent

DT₉₀ (lab at 20 °C)

DT₉₀ (field)

DT₅₀ modelling endpoint

Note

Lab studies DT₅₀ range 28-150 days, field studies DT₅₀ range 6-108 days (USA); Other sources: DT₅₀ 6-10 weeks (R3), 146 days at 25 °C (R3)

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

2.6

Moderately fast

Note

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

Value

Moderately persistent

Note

Rapidly hydrolysed in strong acids and alkalis and at elevated temperatures

Water-sediment DT₅₀ (days)

Moderately fast

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

100

Notes and range

Other sources: 89-513 mL g⁻¹ (R3), Log K_oc 2.00 at 25 °C (R4)

Freundlich

K_f

3.2

Moderately mobile

K_foc

174

¹/_n

1.07

Notes and range

Literature data: K_f range 1.3-6.3 mL g⁻¹, kfoc range 70-429 mL g⁻¹, ¹/_n range 1.04=1.10, Soils = 13

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

2.57

Calculated

Transition state

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

Value

1.52 X 10^-01

Calculated

Note

Potential for particle bound transport index

Low

Calculated

Potential for loss via drain flow

Moderately mobile

Calculated

Bio-concentration factor

BCF (l kg⁻¹)

4.3

(Other literature Log BCF range 0.98-2.5 (R3))

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

2-hydroxyatrazine (Ref: G-34048)

Minor fraction

deisopropyldeethylatrazine (Ref: G-28273)

Minor fraction

0.08

deethylhydroxyatrazine (Ref: G-17794)

Minor fraction

0.08

deisopropylhydroxyatrazine (Ref: G-17792)

Minor fraction

0.08

deisopropyldeethylhydroxyatrazine (Ref: G-17791)

Minor fraction

0.004

6-deisopropyl atrazine (Ref: G-28279)

Major fraction

0.33

desethylatrazine (Ref: G-30033)

Major fraction

0.21

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)

desethylatrazine (Ref: G-30033)

Relevant

2-hydroxyatrazine (Ref: G-34048)

Relevant

deisopropyldeethylatrazine (Ref: G-28273)

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)

1869

Rat

Moderate

Mammals - Short term dietary NOEL

(mg kg⁻¹)

Rat

(ppm diet)

200

Mammals - Chronic 21d NOAEL (mg kg⁻¹ bw d⁻¹)

Birds - Acute LD₅₀ (mg kg⁻¹)

4237

Coturnix japonica

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)

Moderate

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

Low

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

> 100

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)

Beneficial insects (Lacewings)

Beneficial insects (Parasitic wasps)

Beneficial insects (Predatory mites)

Harmless

Typhlodromus pyri

Beneficial insects (Ground beetles)

Aquatic ecotoxicology

Property

Value

Source; quality score; and other information

Interpretation

Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

4.5

Oncorhynchus mykiss

Moderate

Fish - Chronic 21 day NOEC (mg l⁻¹)

Oncorhynchus mykiss

Moderate

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

Daphnia magna

Moderate

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

0.25

Daphnia magna LOEC

Moderate

Aquatic crustaceans - Acute 96 hour LC₅₀ (mg l⁻¹)

1.0

Americamysis bahia

Moderate

Sediment dwelling organisms - Acute 96 hour LC₅₀ (mg l⁻¹)

1.0

Chironomus riparius 1 day

Moderate

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)

0.019

Lemna gibba

Moderate

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

0.059

Raphidocelis subcapitata

Moderate

Algae - Chronic 96 hour NOEC, growth (mg l⁻¹)

0.1

Green algae

Moderate

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)

1869

Rat

Moderate

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

3100

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

5.8

Rat

Other Mammal toxicity endpoints

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

0.02

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

0.1

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

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

None allocated

Dermal penetration studies (%)

EU 1998

Dangerous Substances Directive 76/464

Exposure Routes

Public

Occupational

May be absorbed from the lungs or through intact skin

MRLs

European

EU MRL pesticide database

Great Britain

GB MRL Register

Notes

Drinking Water Standards

Non-statutory WHO drinking water guideline 0.002 mg l⁻¹

UK EA QS database 2018

Drinking Water MAC (μg l⁻¹)

Mammalian dose elimination route and rate

In rats, after 72hrs ~65% excreted in urine and remainder retained by liver, kidneys and lungs

Health issues

Specific human health issues

Carcinogen

Genotoxic

Endocrine disruptor

; ; ; ;

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

Respiratory tract irritant

Skin irritant

Skin sensitiser

Eye irritant

Phototoxicant

No data found

General human health issues

IARC Group 3 carcinogen - not classifiable; Toxics Release Inventory (TRI) Program listed carcinogen
May cause coma, circulatory collapse and gastric bleeding
May cause renal failure
May disturb testosterone metabolism
Endocrine issues - Androgen inhibition, weak estrogenic effect

Handling issues

Property

Value and interpretation

General

Avoid the formation of dust
Powders may become explosive under certain conditions
Store away from heat, flames and sparks
Not expected to auto-ignite

CLP classification 2013

Health: H317, H373
Environment: H400, H410

WHO Classification

III (Slightly hazardous)

UN Number

Waste disposal & packaging

Shelf-life, storage, stability and reactivity

TRANSLATIONS

Language

Name

English

atrazine

French

atrazine

German

Atrazin

Danish

atrazin

Italian

atrazina

Spanish

atrazina

Greek

atrazine

Polish

atrazyna

Swedish

Hungarian

atrazine

Dutch

atrazine

Norwegian

Record last updated:	12/10/2023
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