chlorpyrifos (Ref: OMS 971) ** ENT 27311 ** chlorpyriphos ** Dowco 179 ** chlorpyrifos ethyl ** Translations

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SUMMARY

An organophosphate insecticide approved for use in the EU. It has a low aqueous solubility, is quite volatile and is non-mobile. There is a low risk of leaching to groundwater based on its chemical properties. It can be moderately persistent in soil systems but is not usually persistent in water systems. It is highly toxic to mammals, is classified as a reproduction toxicant, an acetyl cholinesterase inhibitor and a neurotoxicant. It is also a skin and eye irritant. It is highly toxic to birds, fish, aquatic inverterbrates and honey bees and moderately toxic to aquatic plants, algae and earthworms

GENERAL INFORMATION
for chlorpyrifos

Description: A broad spectrum organophosphorus insecticide and acaricide used to control soil and foliage pests

Example pests controlled: Scale; Wooly aphid; Leaf roller; Caterpillars; Corn earworm; Armyworm; Cutworms; Rootworms; Cockroaches; Flea beetles; Flies; Termites; Fire ants

Example applications: Cereals including barley, wheat; Cotton; Fruit including apples, pears, grapes, pineapples, bananas, strawberries, mango; Tomatoes; Nuts; Vegetables inclding carrots, cabbages, cauliflower, Brussel sprouts

Efficacy & activity: Chlorpyrifos has been used very successfully over a long period of time to control a wide range of foliar pests on agricultural crops.

Availability status: Current

Introduction & key dates: 1965, first reported and introduced

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

Status	Approved
Dossier rapporteur/co-rapporteur	Spain/Poland
Date inclusion expires	31/01/2020
EU Candidate for substitution (CfS)	No
Listed in EU database	Yes

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

Chemical structure:

Isomerism	-
Chemical formula	C9H11Cl3NO3PS
Canonical SMILES	CCOP(=S)(OCC)OC1=NC(=C(C=C1Cl)Cl)Cl
Isomeric SMILES	No data
International Chemical Identifier key (InChIKey)	SBPBAQFWLVIOKP-UHFFFAOYSA-N
International Chemical Identifier (InChI)	InChI=1S/C9H11Cl3NO3PS/c1-3-14-17(18,15-4-2)16-9-7(11)5-6(10)8(12)13-9/h5H,3-4H2,1-2H3
2D structure diagram/image available?	Yes

Cambridge Crystallographic Data Centre diagrams:

Common Name	Relationship	Link
Chlorpyrifos	-

General status:

Pesticide type	Insecticide
Substance group	Organophosphate
Minimum active substance purity	970 g/kg
Known relevant impurities	EU dossier - Sulfotep <3.0 g/kg, Acetone insolubles <5.0 g/kg
Substance origin	Synthetic
Mode of action	Non-systemic with contact, inhalation and stomach action. Acetylcholinesterase (AChE) inhibitor.
CAS RN	2921-88-2
EC number	220-864-4
CIPAC number	221
US EPA chemical code	059101
PubChem CID	2730
Molecular mass (g mol-1)	350.58
PIN (Preferred Identification Name)	O,O-diethyl O-(3,5,6-trichloropyridin-2-yl) phosphorothioate
IUPAC name	O,O-diethyl O-3,5,6-trichloro-2-pyridyl phosphorothioate
CAS name	O,O-diethyl O-(3,5,6-trichloro-2-pyridinyl) phosphorothioate
Other status information	OSPAR soc; WFD priority substance; Marine Pollutant
Relevant Environmental Water Quality Standards	UK Environment Agency non-statutory standard for the protection of aquatic life: Freshwater annual average 0.002 ug/L, max acceptable conc 0.01 ug/L; Saltwater annual average 0.001 ug/L, max acceptable conc 0.01 ug/L
Herbicide Resistance Classification (HRAC)	Not applicable
Herbicide Resistance Classification (WSSA)	Not applicable
Insecticide Resistance Classification (IRAC)	1B
Fungicide Resistance Classification (FRAC)	Not applicable
Examples of recorded resistance	Aedes aegypti Aedes nigromaculis Anopheles pharoensis Bemisia argentifolii Culex pipiens pipiens Helicoverpa armigera Plutella xylostella Spodoptera litura Tribolium castaneum plus others
Physical state	White to light brown coloured crystals
Related substances & organisms	-

Formulations:

Property	Value
Example manufacturers & suppliers of products using this active now or historically	Dow AgroSciences Headland Makhteshim-Agan SumiAgro Scotts
Example products using this active	Alpha Chlorpyrifos Ballad Cyren Dursban WG Equity Govern Parapet
UK LERAP status	Buffer probably required in UK - see product label
Formulation and application details	Usually supplied as an emulsifiable concentrates that is mixed with water and applied as a spray. Also supplied as granules for direct application to soil.

ENVIRONMENTAL FATE
for chlorpyrifos

Property		Value	Source/Quality Score/Other Information	Interpretation
Solubility - In water at 20oC (mg l-1)		1.05	A5	Low
Solubility - In organic solvents at 20oC (mg l-1)		774000	A5 - Hexane	-
		290000	A5 - Methanol	-
		4000000	A5 - Ethyl acetate	-
		4000000	A5 - Toluene	-
Melting point (oC)		42	A5	-
Boiling point (oC)		Decomposes before boiling	A5	-
Degradation point (oC)		170	A5	-
Flashpoint (oC)		Not expected to self ignite; Not highly flammable	A5	-
Octanol-water partition coefficient at pH 7, 20oC	P	5.01 X 1004	Calculated	-
	Log P	4.7	A5	High
Bulk density (g ml-1)/Specific gravity		1.51	A5	-
Dissociation constant (pKa) at 25oC		Not applicable	A5	-
		Note: No dissociation
Vapour pressure at 20oC (mPa)		1.43	A5	Low volatility
Henry's law constant at 25oC (Pa m3 mol-1)		0.478	A5	Moderately volatile
GUS leaching potential index		1.04	Calculated	Low leachability
SCI-GROW groundwater index (μg l-1) for a 1 kg ha-1 or 1 l ha-1 application rate	Value	2.20 X 10-02	Calculated	-
	Note	-
Potential for particle bound transport index		-	Calculated	High
Maximum UV-vis absorption L mol-1 cm-1		Neutral soln: 203nm=21174, 230nm=10359, 290nm=5620 Acid soln: 203nm=22223, 230nm=10347, 290nm=5907 Alkaline soln: 242nm=9413, 290nm=1633, 323nm=6701	A5	-
Surface tension (mN m-1)		-	-	-

Degradation:

Property		Value	Source/Quality Score/Other Information	Interpretation
General biodegradability		Not readily biodegradable
Soil degradation (days) (aerobic)	DT50 (typical)	386	A5	Very persistent
	DT50 (lab at 20oC)	386	A5	Very persistent
	DT50 (field)	27.6	A5	Non-persistent
	DT90 (lab at 20oC)	250	A5 EU 2005 data	-
	DT90 (field)	113	A5	-
	DT50 modelling endpoint	23.4	A5 geometric mean	-
	Note	EU 2017 dossier Lab studies DT50 range 19.8->1000 days, Soils=8, Field - studies DT50 range 0.32-88.9 days, DT90 range 12.2-295 days, Soils =6
Dissipation rate RL50 on plant matrix	Value	3.3	R4	-
	Note	Published literature RL50 range 0.7-10.0 days, 11 field & undercover grown crops, various matrices, n=12
Dissipation rate RL50 on and in plant matrix	Value	7.2	R4	-
	Note	Published literature RL50 range 0.95-127.0 days, 30 field & undercover grown crops, various matrices, n=77
Aqueous photolysis DT50 (days) at pH 7	Value	29.6	A5	Slow
	Note	-
Aqueous hydrolysis DT50 (days) at 20oC and pH 7	Value	53.5	A5	Moderately persistent
	Note	pH sensitive 63-73 days @ pH 5, 16-23 days @ pH 8
Water-sediment DT50 (days)		36.5	A5	Moderately fast
Water phase only DT50 (days)		5	A5	Moderately fast

Soil adsorption and mobility:

Property		Value	Source/Quality Score/Other Information	Interpretation
Linear	Kd	126.6	A5	Non-mobile
	Koc	5509
	Notes and range	EU 2017 dossier Kd range 55.2-295 mL/g, Koc range 3187-7733 mL/g, Soils=5; Other sources: 6070 mL/g (DW3), >5000 (E4)
Freundlich	Kf	91.6	A5	Slightly mobile
	Kfoc	3954
	1/n	0.92
	Notes and range	EU 2017 dossier Kf range 45.2-234 mL/g, Kfoc range 1520-5442 mL./g, 1/n range 0.86-0.97, Soils=5
pH sensitivity		No

Key metabolites:

Metabolite		Formation medium	Estimated maximum occurrence fraction	1107/2009 relevancy
3,5,6-trichloro-2-pyridinol		Soil	0.602	Major fraction, Relevant
2,3,5-trichloro-6-methoxypyridine		Soil	0.087	Minor fraction, Relevant

Other known metabolites:

Metabolite name and reference	Aliases	Formation medium / Rate	Estimated maximum occurrence fraction	Metabolising enzymes
O-ethyl-O-(3,5,6-trichloro-2-pyridyl)phosphorothioic acid	phosphorothioate	Water (Hydrolysis)	>0.100	-

ECOTOXICOLOGY
for chlorpyrifos

Property		Value	Source/Quality Score/Other Information	Interpretation
Bio-concentration factor	BCF (l kg-1)	1374	A5 (Other literature log BCF range 0.8-5.4 (R3)	Threshold for concern
	CT50 (days)	2.5		-
Mammals - Acute oral LD50 (mg kg-1)		66	A5 Rat	High
Mammals - Short term dietary NOEL	(mg kg-1)	1	L2 Rat, 2 year	High
	(ppm diet)	-		-
Birds - Acute LD50 (mg kg-1)		39.2	A5 Colinus virginianus	High
Birds - Short term dietary (LC50/LD50)		203 ppm	A5 Anas platyrhynchos	-
Fish - Acute 96 hour LC50 (mg l-1)		0.025	A5 Oncorhynchus mykiss	High
Fish - Chronic 21 day NOEC (mg l-1)		0.00014	A5 Oncorhynchus mykiss	High
Aquatic invertebrates - Acute 48 hour EC50 (mg l-1)		0.00010	A5 Daphnia magna	High
Aquatic invertebrates - Chronic 21 day NOEC (mg l-1)		0.0046	A5 Daphnia magna	High
Aquatic crustaceans - Acute 96 hour LC50 (mg l-1)		0.00004	F4 Americamysis bahia	High
Sediment dwelling organisms - Acute 96 hour LC50 (mg l-1)		0.000024	F4 Chironomus riparius	High
Sediment dwelling organisms - Chronic 28 day NOEC, static, water (mg l-1)		0.0001	F4 Chironomus riparius	High
Sediment dwelling organisms - Chronic 28 day NOEC, sediment (mg kg-1)		-	-	-
Aquatic plants - Acute 7 day EC50, biomass (mg l-1)		0.53	R4 Lemna minor	Moderate
Non-target plants		-	-	-
		-	-	-
Algae - Acute 72 hour EC50, growth (mg l-1)		0.48	H4 Unknown species	Moderate
Algae - Chronic 96 hour NOEC, growth (mg l-1)		0.043	Q2 Unknown species	Moderate
Honeybees	Contact acute 48 hour LD50 (μg bee-1)	0.059	A5	High
	Oral acute 48 hour LD50 (μg bee-1)	0.25	A5	High
	Unknown mode acute 48 hour LD50 (μg bee-1)	-	-	-
Earthworms - Acute 14 day LC50 (mg kg-1)		129	A5 Eisenia foetida	Moderate
Earthworms - Chronic 14 day NOEC, reproduction (mg kg-1)		12.7	A5 Eisenia foetida	Moderate
Other soil macro-organisms - e.g. Collembola	LR50 / EC50 / NOEC / % Effect	0.2	A5 Folsomia candida, 35day LC50 Mortality mg kg-1	-
Other arthropod (1)	LR50 g ha-1	0.2	A5 Aphidius colemani	-
	% Effect	100	Mortality Dose: Field rate Q2 Galendromus occidentalis	-
Other arthropod (2)	LR50 g ha-1	1986	A5 Typhlodromus pyri	-
	% Effect	100	Mortality Dose: Field rate Q2 Neoseiulus fallacis	-
Soil micro-organisms		Nitrogen mineralisation: No significant adverse effect Carbon mineralisation: No significant adverse effect	A5 Dose: 4.8 kg ha-1	-
Mesocosm study data	NOEAEC mg l-1	0.1	A5 EAC	-
	NOEAEC mg l-1	-	-	-

HUMAN HEALTH AND PROTECTION
for chlorpyrifos

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)		66	A5 Rat	High
Mammals - Dermal LD50 (mg kg-1 body weight)		> 1250	A5 Rat	-
Mammals - Inhalation LC50 (mg l-1)		0.1	A5 Rat (whole body)	-
Other Mammal toxicity endpoints		-		-
ADI - Acceptable Daily Intake (mg kg-1bw day-1)		0.001	A5	-
ARfD - Acute Reference Dose (mg kg-1bw day-1)		0.005	A5	-
AAOEL - Acute Acceptable Operator Exposure Level (mg kg-1 bw day-1)		-	-	-
AOEL - Acceptable Operator Exposure Level - Systemic (mg kg-1bw day-1)		0.001	A5	-
Dermal penetration studies (%)		0.2-25	A5 concentration & product dependent	-
Dangerous Substances Directive 76/464		List I; List II	-	-
Exposure Limits		[UK LT TWA 8 hr: 0.2 mg/m3], [UK STEL 15 mins: 0.6 mg/m3]	MEL UK HSE	-
Exposure Routes	Public	Possible risks of exposure when close to spraying activity
	Occupational	PPE/PPC required to mitigate any expsoure risks
European MRLs		Click here for the EU MRL pesticide database
Drinking Water Standards		Non-statutory WHO drinking water guideline 0.03 mg/L	UK EA QS database, 2018	-
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		Highly toxic by ingestion Some studies indicate a link between chlorpyrifos metabolites and learning difficulties in children Suspected cardiovascular & blood 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 6.1
CLP classification 2013		Health: H301 Environment: H400, H410
EC Risk Classification		T - Toxic: R25 Xn - Harmful: R21, R43 N - Dangerous for the environment: R50, R53
EC Safety Classification		S1/2, S45, S60, S61
WHO Classification		II	-	Moderately hazardous
US EPA Classification (formulation)		II	-	Warning - Moderately toxic
UN Number		Active 2783, liquid products usually 3018
Waste disposal & packaging		Packaging Group III (minor danger)

TRANSLATIONS
for chlorpyrifos

Language	Name
English	chlorpyrifos
French	chlorpyriphos
German	Chlorpyrifos
Danish	chlorpyrifos
Italian	clorpirifos
Spanish	clorpirifos
Greek	chlorpyrifos
Slovenian	klorpirifos
Polish	chloropyrifos
Swedish	klorpyrifos
Hungarian	chlorpyrifos
Dutch	chloorpyrifos

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Record last updated: Wednesday 03 April 2019
Contact: aeru@herts.ac.uk