paraquat (Ref: PP 148) ** orthoparaquat ** PP 910 ** Translations

---

Environmental Fate - Ecotoxicology - Human Health - A to Z Index - Home

GENERAL INFORMATION
for paraquat

Description: A herbicide used to control common weeds in a wide range of agricultural and amenity situations

Example pests controlled: Broad-leaved weeds including cocksfoot; Grasses including wild oats, Yorkshire fog grass, ryegrass, fescue

Example applications: Rice; Lucerne; Beans & peas; Hops; Vineyards; Potaoes; Non-cropped areas such as roadways, paths

Availability status: Current

Introduction & key dates: 1962

EC Regulation 1107/2009 (repealing 91/414):

Status	Not approved
Dossier rapporteur/co-rapporteur	UK
Date inclusion expires	Expired

Approved for use () or known to be used () in the following European countries:

AT

BE

BG

CY

CZ

DE

DK

EE

EL

ES

FI

FR

HR

HU

IE

IT

LT

LU

LV

MT

NL

PL

PT

RO

SE

SI

SK

UK

Also used in: Australia, USA, Canada, Mexico, Brazil, Japan, India, China, Indonesia, Thailand, New Zealand

General status:

Pesticide type	Herbicide
Substance group	Bipyridylium
Minimum active substance purity	-
Known relevant impurities	EU dossier - free 4,4¢-bipyridyl
Substance origin	Synthetic
Mode of action	Broad-spectrum, non-residual activity with contact and some desiccant action. Photosystem I (electron transport) inhibitor.
CAS RN	4685-14-7
EC number	217-615-7
CIPAC number	56
US EPA chemical code	-
Chiral molecule	No
Chemical formula	C12H14N2
SMILES	c2cc(c1cc[n+](cc1)C)cc[n+]2C
International Chemical Identifier key (InChIKey)	INFDPOAKFNIJBF-UHFFFAOYSA-N
International Chemical Identifier (InChI)	InChI=1S/C12H14N2/c1-13-7-3-11(4-8-13)12-5-9-14(2)10-6-12/h3-10H,1-2H3/q+2
Structure diagram/image available?	Yes
Molecular mass (g mol-1)	186.25
PIN (Preferred Identification Name)	-
IUPAC name	1,1'-dimethyl-4,4'-bipyridinium
CAS name	1,1'-dimethyl-4,4'-bipyridinium
Other status information	PAN Dirty Dozen; Chemical subject to PIC regulations
Herbicide Resistance Classification (HRAC)	D
Herbicide Resistance Classification (WSSA)	22
Insecticide Resistance Classification (IRAC)	Not applicable
Fungicide Resistance Classification (FRAC)	Not applicable
Examples of recorded resistance	Lolium rigidum
Physical state	Colourless to pale yellow crystalline solid
Related substances & organisms	diquat dibromide

Formulations:

Property	Value
Example manufacturers & suppliers of products using this active now or historically	AgriGuard Clayton Syngenta
Example products using this active	AgriGuard Paraquat
UK LERAP status	None
Formulation and application details	Often supplied as a soluble concentrate that is mixed with water and used as a spray.

ENVIRONMENTAL FATE
for paraquat

Property		Value	Source/Quality Score/Other Information	Interpretation
Solubility - In water at 20oC (mg l-1)		620000	A5	High
Solubility - In organic solvents at 20oC (mg l-1)		143000	A5 - Methanol	-
		100	A5 - Acetone	-
		100	A5 - Toluene	-
		100	A5 - Hexane	-
Melting point (oC)		-	-	-
Boiling point (oC)		-	-	-
Degradation point (oC)		-	-	-
Flashpoint (oC)		-	-	-
Octanol-water partition coefficient at pH 7, 20oC	P	3.16 X 10-05	Calculated	-
	Log P	-4.5	A5	Low
Bulk density (g ml-1)/Specific gravity		1.5	A5	-
Dissociation constant (pKa) at 25oC		Not applicable	A5	-
		Note: No dissociation
Vapour pressure at 25oC (mPa)		0.01	A3	Low volatility
Henry's law constant at 25oC (Pa m3 mol-1)		4.00 X 10-12	A5	Non-volatile
Henry's law constant at 20oC (dimensionless)		1.23 X 10-12	Calculated	Non-volatile
GUS leaching potential index		-7.40	Calculated	Low leachability
SCI-GROW groundwater index (μg l-1) for a 1 kg ha-1 or 1 l ha-1 application rate	Value	5.35 X 10-03	Calculated	-
	Note	Estimated concentrations of chemicals with Koc values greater than 9995 ml g-1 are beyond the scope of the regression data used in SCI-GROW development. If there are concerns for such chemicals, a higher tier groundwater exposure assessment should be considered, regardless of the concentration returned by SCI-GROW
Potential for particle bound transport index		-	Calculated	High
Maximum UV-vis absorption L mol-1 cm-1		290nm	A5	-
Surface tension (mN m-1)		-	-	-

Degradation:

Property		Value	Source/Quality Score/Other Information	Interpretation
Soil degradation (days) (aerobic)	DT50 (typical)	3000	A5	Very persistent
	DT50 (lab at 20oC)	5000	Y3	Very persistent
	DT50 (field)	2800	A5	Very persistent
	DT90 (lab at 20oC)	-	-	-
	DT90 (field)	-	-	-
	Note	Field studies DT50 range 7-8 years (UK)
Plant matrix DT50 (days)	Value	-	-	-
	Note	-
Aqueous photolysis DT50 (days) at pH 7	Value	Stable	A5	-
	Note	-
Aqueous hydrolysis DT50 (days) at 20oC and pH 7	Value	Stable	A5	-
	Note	Stable pH 5 to pH 9, 30 days at 25 and 40 degC
Water-sediment DT50 (days)		Stable	Q2	-
Water phase only DT50 (days)		10	Q2	Moderately fast

Soil adsorption and mobility:

Property		Value	Source/Quality Score/Other Information	Interpretation
Linear	Kd	-	A3	Non-mobile
	Koc	1000000
	Notes and range	-
Freundlich	Kf	-	-	-
	Kfoc	-
	1/n	-
	Notes and range	-
pH sensitivity		-

ECOTOXICOLOGY
for paraquat

Property		Value	Source/Quality Score/Other Information	Interpretation
Bio-concentration factor	BCF (l kg-1)	Low risk	A5 Based on LogP < 3	Low potential
	CT50 (days)	-		-
Mammals - Acute oral LD50 (mg kg-1)		110	G4 Rat	Moderate
Mammals - Short term dietary NOEL	(mg kg-1)	-	A5 Rat	-
	(ppm diet)	> 100		-
Birds - Acute LD50 (mg kg-1)		35	A4 Unknown species	High
Birds - Short term dietary (LC50/LD50)		698 mg kg feed-1	A4 unknown species	-
Fish - Acute 96 hour LC50 (mg l-1)		19	A5 Oncorhynchus mykiss	Moderate
Fish - Chronic 21 day NOEC (mg l-1)		-	-	-
Aquatic invertebrates - Acute 48 hour EC50 (mg l-1)		4.4	A5 Daphnia magna	Moderate
Aquatic invertebrates - Chronic 21 day NOEC (mg l-1)		0.12	A5 Daphnia magna	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)		0.367	A5 Chironomus riparius	Moderate
Sediment dwelling organisms - Chronic 28 day NOEC, sediment (mg kg-1)		> 100	A5 Chironomus riparius	Low
Aquatic plants - Acute 7 day EC50, biomass (mg l-1)		0.037	A5 Lemna gibba	Moderate
Non-target plants		-	-	-
		-	-	-
Algae - Acute 72 hour EC50, growth (mg l-1)		0.00023	A5 Raphidocelis subcapitata	High
Algae - Chronic 96 hour NOEC, growth (mg l-1)		-	-	-
Honeybees	Contact acute 48 hour LD50 (μg bee-1)	9.26	A5	Moderate
	Oral acute 48 hour LD50 (μg bee-1)	> 9.06	A5	Moderate
	Unknown mode acute 48 hour LD50 (μg bee-1)	-	-	-
Earthworms - Acute 14 day LC50 (mg kg-1)		> 1000	A5 Eisenia foetida	Low
Earthworms - Chronic 14 day NOEC, reproduction (mg kg-1)		-	-	-
Other soil macro-organisms - e.g. Collembola	LR50 / EC50 / NOEC / % Effect	-	-	-
Other arthropod (1)	LR50 g ha-1	-	-	-
	% Effect	0	Mortality Dose: 0.01 kg ha-1 A5 Pardosa spp., adult	-
Other arthropod (2)	LR50 g ha-1	-	-	-
	% Effect	0	Mortality Dose: 0.01 kg ha-1 A5 Aleochara bilineata, adult	-
Soil micro-organisms		Nitrogen mineralisation: No significant adverse effect Carbon mineralisation: No significant adverse effect	A5 Dose: 720 kg ha-1, 1 year	-
Mesocosm study data	NOEAEC mg l-1	-	-	-
	NOEAEC mg l-1	-	-	-

HUMAN HEALTH AND PROTECTION
for paraquat

General:

Property		Value	Source/Quality Score/Other Information	Interpretation
Threshold of Toxicological Concern (Cramer Class)		High (class III)	-	-
Mammals - Acute oral LD50 (mg kg-1)		110	G4 Rat	Moderate
Mammals - Dermal LD50 (mg kg-1 body weight)		> 200	A4 Rat	-
Mammals - Inhalation LC50 (mg l-1)		0.6	A5 Rat	-
Other Mammal toxicity endpoints		-		-
ADI - Acceptable Daily Intake (mg kg-1bw day-1)		0.004	A5 Dog, SF=100	-
ARfD - Acute Reference Dose (mg kg-1bw day-1)		0.005	A5 Dog, SF=100	-
AOEL - Acceptable Operator Exposure Level - Systemic (mg kg-1bw day-1)		0.0004	A5 Dog, 90 day, SF=100	-
Dermal penetration studies (%)		0.5	A5	-
Dangerous Substances Directive 76/464		[No unacceptable risks to bystanders identified]	-	-
Exposure Limits		[LT TWA 8hr: 0.1 mg/m3]	Occupation Exposure	-
Exposure Routes	Public	No unacceptable risks to operators or other workers identified
	Occupational	-
European MRLs		Click here for the EU MRL pesticide database
Drinking Water MAC (μg l-1)		-	-	-

Health issues:

Carcinogen	Mutagen	Endocrine disrupter	Reproduction / development effects	Cholinesterase inhibitor	Neurotoxicant
Respiratory tract irritant	Skin irritant	Skin sensitiser	Eye irritant	Phototoxicant
		-		-
General human health issues		Potential liver, kidney, stomach, intestine and respiratory system toxicant

: Yes, known to cause a problem
: No, known not to cause a problem
: Possibly, status not identified
- : No data found

Handling issues:

Property		Value	Source/Quality Score/Other Information	Interpretation
General		Not explosive or oxidising IMDG Transport Code is usually 6.1
CLP classification 2013		Health: H301, H311, H315, H319, H330, H335, H372 Environment: H400, H410
EC Risk Classification		T+ - Very toxic: R26 T - Toxic: R24/25, R48/25 Xi - Irritant: R36/37/38 N - Dangerous for the environment: R50, R53
EC Safety Classification		S1/2, S22, S28, S36/37/39, S45, S60, S61
WHO Classification		II	-	Moderately hazardous
US EPA Classification (formulation)		No consensus across products or no products available	-	-
UN Number		2781
Waste disposal & packaging		Packaging Group II (medium danger)

TRANSLATIONS
for paraquat

Language	Name
English	paraquat
French	paraquat
German	Paraquat
Danish	paraquat
Italian	paraquat
Spanish	paracuat
Greek	-
Slovenian	parakvat
Polish	parakwat
Swedish	-
Hungarian	-
Dutch	-

---

Record last updated: Thursday 19 November 2015
Contact: aeru@herts.ac.uk