Terbuthylazine

Terbuthylazine	Last updated: 16/03/2021
(Also known as: bellacide)

GENERAL INFORMATION

Description

A herbicide to control grass and broad-leaved weeds in a variety of situations including forestry and for control slime-forming algae, fungi, and bacteria in non-agricultural situations

Example pests controlled

Pigwed; Goosefoot; Bladder weed; Dwarf marigold; Blackjack; Starbur; Evening primrose

Example applications

Maize; Sorghum; Apples; Citrus; Bush vines; Non-crop sites including roads, railways, industrial sites

Efficacy & activity

Availability status

Current

Introduction & key dates

1967

UK regulatory status

UK COPR regulatory status

Not approved

Date COPR inclusion expires

Not applicable

UK LERAP status

Not applicable

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status

Approved

Dossier rapporteur/co-rapporteur

Spain/Hungary

Date EC 1107/2009 inclusion expires

31/12/2021

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

Australia, New Zealand

Chemical structure

Isomerism

Chemical formula

C₉H₁₆ClN₅

Canonical SMILES

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

Isomeric SMILES

No data

International Chemical Identifier key (InChIKey)

FZXISNSWEXTPMF-UHFFFAOYSA-N

International Chemical Identifier (InChI)

InChI=1S/C9H16ClN5/c1-5-11-7-12-6(10)13-8(14-7)15-9(2,3)4/h5H2,1-4H3,(H2,11,12,13,14,15)

2D structure diagram/image available?

Yes

Cambridge Crystallographic Data Centre diagrams

Common Name	Relationship	Link
terbuthylazine	-

General status

Pesticide type

Herbicide, Microbiocide, Algicide

Substance group

Triazine

Minimum active substance purity

930 g kg⁻¹, typically 960-980 g kg⁻¹

Known relevant impurities

EU 2017 dossier - propazine, atrazine, simazine

Substance origin

Synthetic

Mode of action

Broad-spectrum with strong and rapid effects. Inhibits photosynthesis (photosystem II).

CAS RN

5915-41-3

EC number

227-637-9

CIPAC number

234

US EPA chemical code

080814

PubChem CID

22206

Molecular mass

229.71

PIN (Preferred Identification Name)

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

IUPAC name

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

CAS name

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

Other status information

Relevant Environmental Water Quality Standards

Herbicide Resistance Classification (HRAC)

Herbicide Resistance Classification (WSSA)

Insecticide Resistance Classification (IRAC)

Not applicable

Fungicide Resistance Classification (FRAC)

Not applicable

Examples of recorded resistance

Physical state

White crystalline powder

Related substances & organisms

ethylene glycol

bromoxynil

isoxaben

mesotrione

S-metolachlor

Formulations

Property

Value

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

Calaris
Skirmish
Gardo Gold

Example products using this active

Makhteshim
Orion Crop Protection Ltd
Sipcam
Syngenta

Formulation and application details

Usually supplied as a suspension concentrate or suspended emulsion formulation

ENVIRONMENTAL FATE

Property

Value

Source; quality score; and other information

Interpretation

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

6.6

Low

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

41000

Acetone

9800

Toluene

12000

n-Octanol

410

n-Hexane

Melting point (°C)

175

Boiling point (°C)

Decomposes before boiling

Degradation point (°C)

224

Flashpoint (°C)

Not expected to self ignite; Not highly flammable

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

2.51 X 10⁰³

Calculated

Log P

3.4

High

Bulk density (g ml⁻¹)

1.19

Dissociation constant pKa) at 25 °C

1.9

Vapour pressure at 20 °C (mPa)

0.152

Low volatility

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

2.3 X 10^-03

Non-volatile

Maximum UV-vis absorption L mol⁻¹ cm⁻¹

Neutral solution: 222nm = 385386, 263nm = 3444
Acidic solution: 223nm = 30103, 263nm=4468
Basic solution, 223nm = 37426, 263nm = 3395

Surface tension (mN m⁻¹)

71.8

at 20°C 90% soln

Degradation

Property

Value

Source; quality score; and other information

Interpretation

General biodegradability

Not readily biodegradable

Soil degradation (days) (aerobic)

DT₅₀ (typical)

72.0

Moderately persistent

DT₅₀ (lab at 20 °C)

72.0

Moderately persistent

DT₅₀ (field)

21.8

Non-persistent

DT₉₀ (lab at 20 °C)

353

Persistent

DT₉₀ (field)

72.6

DT₅₀ modelling endpoint

Note

EU 2017 dossier lab studies DT₅₀ range 38.2-167 days, Soils = 12, Field studies DT₅₀ range 6.43-149 days, DT₉₀ range 1,6-497 days, Soils = 23; EU dossier 2007 lab studies DT₉₀ range 196-837 days; field studies DT₅₀ range 10.0-35.8 days, DT₉₀ range 33.3-119 days

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

Stable

Note

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

Value

Stable

Note

pH variable: stable at pH 7 and pH 9, 73 days at pH 5, 50 °C

Water-sediment DT₅₀ (days)

Moderately fast

Water phase only DT₅₀ (days)

Moderately fast

Soil adsorption and mobility

Property

Value

Source; quality score; and other information

Interpretation

Linear

K_d

K_oc

Notes and range

Freundlich

K_f

5.1

Moderately mobile

K_foc

231

¹/_n

0.93

Notes and range

EU dossier K_f range 2.1-10.49 mL g⁻¹, K_foc range 151-333 mL g⁻¹, ¹/_n range 0.88-0.98, Soils=9

pH sensitivity

Fate indices

Property

Value

Source; quality score; and other information

Interpretation

GUS leaching potential index

2.19

Calculated

Transition state

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

Value

8.43 X 10^-02

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

desethyl-terbuthylazine (Ref: GS26379)

Soil

0.251

Major fraction, Relevant

hydroxy-terbuthylazine (Ref: GS 23158)

Soil

0.345

Major fraction, Relevant

2-hydroxy-desethyl-terbuthylazine (Ref: GS 28620)

Soil

Relevant

Other known metabolites

Metabolite name and reference

Aliases

Formation medium / Rate

Estimated maximum occurrence fraction

Metabolising enzymes

terbutryn (Ref: GS 14260)

MT26

Sediment

de-t-butyl-hydroxy terbuthylazine

MT19

diamino-chlorotriazine

MT20

Plant

de-t-butyl-terbuthylazine

MT22

amino-dihydroxy triazine

MT24

ECOTOXICOLOGY

Property

Value

Source; quality score; and other information

Interpretation

Bio-concentration factor

BCF (l kg⁻¹)

Whole fish

Low potential

CT₅₀ (days)

0.8

Mammals - Acute oral LD₅₀ (mg kg⁻¹)

> 1000

Rat

Moderate

Mammals - Short term dietary NOEL

(mg kg⁻¹)

> 0.22

Rat 2 year

High

(ppm diet)

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

4.5

Unknown species Reproductive NOAEL

High

Birds - Acute LD₅₀ (mg kg⁻¹)

> 1236

Colinus virginianus

Moderate

Birds - Short term dietary (LC₅₀/LD₅₀)

> 395 mg kg bw⁻¹ day⁻¹

Anas platyrhynchos

Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)

13.84

Coturnix japonica NOEL

Moderate

Fish - Acute 96 hour LC₅₀ (mg l⁻¹)

2.2

Oncorhynchus mykiss

Moderate

Fish - Chronic 21 day NOEC (mg l⁻¹)

0.09

Oncorhynchus mykiss

Moderate

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

21.2

Daphnia magna

Moderate

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

0.019

Daphnia magna

Moderate

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

0.167

Americamysis bahia

Moderate

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

Sediment dwelling organisms - Chronic 28 day NOEC, static, water (mg l⁻¹)

0.5

Chironomus riparius

Moderate

Sediment dwelling organisms - Chronic 28 day NOEC, sediment (mg kg⁻¹)

Aquatic plants - Acute 7 day EC₅₀, biomass (mg l⁻¹)

0.0128

Lemna gibba

Moderate

Non-target plants

321

Lettuce
Pre-emergence, EC₅₀
as mL product ha⁻¹ (Gardoprim Plus Gold containing 187.5 g l⁻¹ terbuthylazine)

439

Lettuce
Post-emergence, EC₅₀
as mL product ha⁻¹ (Gardoprim Plus Gold containing 187.5 g l⁻¹ terbuthylazine)

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

0.012

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)

> 32

Moderate

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

> 22.6

Moderate

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)

> 141.7

Eisenia foetida corr

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

750

>, Mortality
Typhlodromus pyri

% Effect

Other arthropod (2)

LR₅₀ g ha⁻¹

750

>, Mortality
Aphidius rhopalosiphi

% Effect

Soil micro-organisms

Nitrogen mineralisation: No significant adverse effect
Carbon mineralisation: No significant adverse effect

Dose: 10.9 mg kg⁻¹ soil

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)

> 1000

Rat

Moderate

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

2000

Rat

Mammals - Inhalation LC₅₀ (mg l⁻¹)

> 5.3

Rat 4 hr (nose only)

Other Mammal toxicity endpoints

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

0.004

Dog SF=100

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

0.008

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

None reported

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

0.0032

Dermal penetration studies (%)

0.1-2.5

concentration dependent

Dangerous Substances Directive 76/464

Exposure Routes

Public

Acceptable for proposed uses

Occupational

Acceptable risk for authorised agricultural uses

MRLs

European

EU MRL pesticide database

Notes

Drinking Water Standards

Non-statutory WHO drinking water guideline 0.007 mg l⁻¹

UK EA QS database 2018

Drinking Water MAC (μg l⁻¹)

Health issues

Specific human health issues

Carcinogen

Genotoxic

Endocrine disruptor

; ; ; ;

No data found

Reproduction / development effects

Acetyl cholinesterase inhibitor

Neurotoxicant

No data found

Respiratory tract irritant

Skin irritant

Skin sensitiser

Eye irritant

Phototoxicant

No data found

General human health issues

Toxic, may be fatal if inhaled, swallowed or absorbed through skin
Health effects may be delayed
Weak skin sensitiser

Handling issues

Property

Value and interpretation

General

Not explosive or oxidising
IMDG Transport Code is usually 6.1

CLP classification 2013

Health: H373, H302
Environment: H400, H410

EC Risk Classification

Xn - Harmful: R22

EC Safety Classification

S13, S36

WHO Classification

III (Slightly hazardous)

UN Number

Usually 1230 or 2763

Waste disposal & packaging

Packaging Group II (medium danger) or III (minor danger)

TRANSLATIONS

Language

Name

English

terbuthylazine

French

terbuthylazine

German

Terbuthylazin

Danish

terbutylazin

Italian

terbutilazina

Spanish

terbutilazina

Greek

Polish

terbutylazyna

Swedish

Hungarian

terbuthylazine

Dutch

terbuthylazine

Record last updated:	16/03/2021
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