Atrazine (Ref: G 30027)

Atrazine (Ref: G 30027)	Last updated: 18/06/2020
(Also known as: aneldazin)

SUMMARY

Atrazine is a herbicide that does not have EU approval for use. 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.

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 approval status

Not approved

EC Regulation 1107/2009 (repealing 91/414)

EC Directive 91/414 Status

Not approved

Dossier rapporteur/co-rapporteur

Date inclusion expires

Expired

EU Candidate for substitution (CfS)

Listed in EU database

Yes

Approved for use (✓) or known to be used (#) in the following EU-27 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

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 group

Triazine

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

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

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 Classification (HRAC)

Herbicide Resistance Classification (WSSA)

Insecticide Resistance Classification (IRAC)

Not applicable

Fungicide Resistance Classification (FRAC)

Not applicable

Examples of recorded resistance

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

Physical state

White crystals

Related substances & organisms

acetochlor

2,4-D

dicamba

sulcotrione

nicosulfuron

terbutryn

Formulations

Property

Value

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

Gesaprim
Fenamin
Atrazinax
Weedex
Primaze
Atratol
Radazine

Example products using this active

Syngenta
Bayer CropScience
Monsanto
Scotts

UK LERAP status

Buffer probably required in UK - see product label

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)

Not expected to self ignite; Not highly flammable

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

5.01 X 10⁰²

Calculated

Log P

2.7

Moderate

Bulk density (g ml⁻¹)

1.23

Dissociation constant pKa) at 25 °C

1.7

Very weak base

Vapour pressure at 20 °C

0.039

Low volatility

Henry's law constant at 25 °C

1.50 X 10^-04

Non-volatile

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

Medium

Calculated

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

Key metabolites

Metabolite

Formation medium

Estimated maximum occurrence fraction

1107/2009 relevancy

6-deisopropyl atrazine (Ref: G-28279)

Soil

0.33

Major, Relevant

deethylatrazine (Ref: G-30033)

Soil

0.21

Major, Relevant

2-hydroxyatrazine (Ref: G-34048)

Soil

Non Relevant

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

Metabolising enzymes

deisopropyldeethylatrazine (Ref: G-28273)

Soil

0.08

deethylhydroxyatrazine (Ref: G-17794)

Soil

0.08

deisopropylhydroxyatrazine (Ref: G-17792)

Soil

0.08

deisopropyldeethylhydroxyatrazine (Ref: G-17791)

Soil

0.004

ECOTOXICOLOGY

Property

Value

Source; quality score; and other information

Interpretation

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

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

1869

Rat

Moderate

Mammals - Short term dietary NOEL

(mg kg⁻¹)

Rat

(ppm diet)

200

Birds - Acute LD₅₀ (mg kg⁻¹)

4237

Coturnix japonica

Low

Birds - Short term dietary (LC₅₀/LD₅₀)

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

Non-target plants

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

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)

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)

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

Typhlodromus pyri

Other arthropod (2)

LR₅₀ g ha⁻¹

% Effect

Harmless

Chrysoperla carnea

Soil micro-organisms

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

JMPR 2007

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

0.1

JMPR 2007

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

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

0.01

EU 1998

Dermal penetration studies (%)

EU 1998

Dangerous Substances Directive 76/464

Exposure Routes

Public

Occupational

May be absorbed from the lungs or through intact skin

European MRLs

EU MRL pesticide database

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)

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
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

CLP classification 2013

Health: H317, H373
Environment: H400, H410

EC Risk Classification

Xn - Harmful: R48/22, R43
N - Dangerous for the environment: R50, R53

EC Safety Classification

S2, S36/37, S61, S60

WHO Classification

III (Slightly hazardous)

UN Number

Waste disposal & packaging

TRANSLATIONS

Language

Name

English

atrazine

French

atrazine

German

Atrazin

Danish

atrazin

Italian

atrazina

Spanish

atrazina

Greek

atrazine

Polish

atrazyna

Swedish

Hungarian

atrazine

Dutch

atrazine

Record last updated:	18/06/2020
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