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Parathion-ethyl (Ref: OMS 19)
(Also known as: parathion; thiophos; ethyl parathion; BAY 9491; ENT 15108; AC 3422)
SUMMARY
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:
Potential for particle bound transport: Medium
Ecotoxicity
High alert:
Birds acute ecotoxicity: High; Daphnia acute ecotoxicity: High; Daphnia chronic ecotoxicity: High; Bees acute oral ecotoxicity: High; Bees acute unknown ecotoxicity: High
Human health
High alert:
Mammals acute toxicity: High; Reproduction/development effects
GENERAL INFORMATION
Description
A broad-spectrum insecticide and acaricide used to control sucking and chewing insects and mites
Example pests controlled
Aphids; Mealybugs; Codling moth; Scale, Leafhoppers
Example applications
Alfalfa; Barley; Rapseed; Cotton; Sorghum; Soybeans; Sunflowers; Wheat; Broccoli; Brussel sprouts
Efficacy & activity
-
Availability status
Considered obsolete but may be available in some countriesl Banned in many countries
Introduction & key dates
circa 1950
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
Italy
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
-
Chemical structure
Isomerism
None
Chemical formula
C₁₀H₁₄NO₅PS
Canonical SMILES
CCOP(=S)(OCC)OC1=CC=C(C=C1)[N+](=O)[O-]
Isomeric SMILES
No data
International Chemical Identifier key (InChIKey)
LCCNCVORNKJIRZ-UHFFFAOYSA-N
International Chemical Identifier (InChI)
InChI=1S/C10H14NO5PS/c1-3-14-17(18,15-4-2)16-10-7-5-9(6-8-10)11(12)13/h5-8H,3-4H2,1-2H3
2D structure diagram/image available?
Yes
General status
Pesticide type
Insecticide, Acaricide
Substance groups
Organophosphate insecticide; Organophosphate acaricide; Organothiophosphate insecticide; Organothiophosphate acaricide
Minimum active substance purity
-
Known relevant impurities
-
Substance origin
Synthetic
Mode of action
Non-systemic with contact, stomach and some respiratory action. Acetylcholinesterase (AChE) inhibitor.
CAS RN
56-38-2
EC number
200-271-7
CIPAC number
10
US EPA chemical code
057501
PubChem CID
991
CLP index number
015-034-00-1
Molecular mass
291.27
PIN (Preferred Identification Name)
O,O-diethyl-O-4-nitrophenyl phosphorothioate
IUPAC name
O,O-diethyl O-4-nitrophenyl phosphorothioate
CAS name
O,O-diethyl O-(4-nitrophenyl) phosphorothioate
Other status information
Chemical subject to PIC regulations Annex III; Potential groundwater contaminant; Marine Pollutant; Rotterdam Convention (Class Ia); Subject to the provisions of the UK Poisons Act 1972
Relevant Environmental Water Quality Standards
-
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
Adoxophyes orana, Aedes dorsalis, Aedes melanimon, Aedes nigromaculis, Amblyseius potentillae, Bemisia tabaci, many others
Physical state
White crystalline solid with foul odour when pure. technical substance may be a pale yellow liquid
Related substances & organisms
Formulations
Property
Value
Example manufacturers & suppliers of products using this active now or historically
  • Bayer Crop Protection
  • Monsanto
  • Cheminova
  • King Tech
  • Fujian Sannong Group Co. Ltd.
Example products using this active
  • Folidol E
  • Niran
  • Woprophos
  • Fighter
  • Co-thion
  • Alkron
  • Vitrex
Formulation and application details
Available in a variety of formulations including dusts, emulsion concentrates, granules, ULV liquids and wettable powders
ENVIRONMENTAL FATE
Property
Value
Source; quality score; and other information
Interpretation
Solubility - In water at 20 °C (mg l⁻¹)
12.4
G4 G = Extension Toxicology network database EXTOXNET. Available online but no longer updated. (click here )
4 = Verified data
 Low
Solubility - In organic solvents at 20 °C (mg l⁻¹)
200000
L3 L = Pesticide manuals and hard copy reference books / other sources
3 = Unverified data of known source
Dichloromethane		 -
200000
L3 L = Pesticide manuals and hard copy reference books / other sources
3 = Unverified data of known source
Toluene		 -
75000
L2 L = Pesticide manuals and hard copy reference books / other sources
2 = Unverified data of unknown source
Hexane		 -
200000
L3 L = Pesticide manuals and hard copy reference books / other sources
3 = Unverified data of known source
Isopropanol		 -
Melting point (°C)
6.1
L3 L = Pesticide manuals and hard copy reference books / other sources
3 = Unverified data of known source
 -
Boiling point (°C)
375
L3 L = Pesticide manuals and hard copy reference books / other sources
3 = Unverified data of known source
 -
Degradation point (°C)
- - -
Flashpoint (°C)
174
L3 L = Pesticide manuals and hard copy reference books / other sources
3 = Unverified data of known source
 -
Octanol-water partition coefficient at pH 7, 20 °C
P
6.76 X 1003 Calculated -
Log P
3.83
G4 G = Extension Toxicology network database EXTOXNET. Available online but no longer updated. (click here )
4 = Verified data
 High
Fat solubility of residues
Solubility
Soluble
A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications )
5 = Verified data used for regulatory purposes
 -
Data type
Regulatory data - observed in metabolism and farm animal feeding studies
A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications )
5 = Verified data used for regulatory purposes
 -
Density (g ml⁻¹)
1.26
AC4 AC = EC Joint Research Centre ESIS European Chemical Substance Information Systems including EINECS, now integrated with the database provided by the European Chemicals Agency (ECHA) (click here )
4 = Verified data
 -
Dissociation constant pKa) at 25 °C
- - -
-
Vapour pressure at 20 °C (mPa)
0.89
L3 L = Pesticide manuals and hard copy reference books / other sources
3 = Unverified data of known source
 Low volatility
Henry's law constant at 25 °C (Pa m³ mol⁻¹)
3.02 X 10-02
L3 L = Pesticide manuals and hard copy reference books / other sources
3 = Unverified data of known source
 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)
49
K4 K = Research datasets (e.g. Pandora, Demetra; these datasets no longer available). Norman Ecotoxicology database. (click here )
4 = Verified data
 Moderately persistent
DT₅₀ (lab at 20 °C)
14
F3 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment )
3 = Unverified data of known source
 Non-persistent
DT₅₀ (field)
17
AC4 AC = EC Joint Research Centre ESIS European Chemical Substance Information Systems including EINECS, now integrated with the database provided by the European Chemicals Agency (ECHA) (click here )
4 = Verified data
 Non-persistent
DT₉₀ (lab at 20 °C)
- - -
DT₉₀ (field)
- - -
DT₅₀ modelling endpoint
- - -
Note
ICULID datasheet DT₅₀ lab studies 3-32 days, field studies DT₅₀ range 2-58 days; Other sources: 7DT₅₀ -10 days (R3)
Dissipation rate RL₅₀ on plant matrix
Value
3.8
R4 R = Peer reviewed scientific publications
4 = Verified data
 -
Note
Published literature RL₅₀ range 0.2-19.6 days, wide range of field grown crops and wide range of matrics, n=30
Dissipation rate RL₅₀ on and in plant matrix
Value
5.1 - -
Note
Published literature RL₅₀ range 0.7-31.1 days, wide range of field grown crops and wide range of matrics, n=32
Aqueous photolysis DT₅₀ (days) at pH 7
Value
30
AC4 AC = EC Joint Research Centre ESIS European Chemical Substance Information Systems including EINECS, now integrated with the database provided by the European Chemicals Agency (ECHA) (click here )
4 = Verified data
 Stable
Note
-
Aqueous hydrolysis DT₅₀ (days) at 20 °C and pH 7
Value
260
L3 L = Pesticide manuals and hard copy reference books / other sources
3 = Unverified data of known source
 Persistent
Note
pH sensitive: DT₅₀ 272 days at pH 4, 130 days at pH 9, all at 22 °C
Water-sediment DT₅₀ (days)
4.3
K4 K = Research datasets (e.g. Pandora, Demetra; these datasets no longer available). Norman Ecotoxicology database. (click here )
4 = Verified data
 Fast
Water phase only DT₅₀ (days)
3.5
K4 K = Research datasets (e.g. Pandora, Demetra; these datasets no longer available). Norman Ecotoxicology database. (click here )
4 = Verified data
 Moderately fast
Soil adsorption and mobility
Property
Value
Source; quality score; and other information
Interpretation
Linear
Kd
-
H3 H = The US ARS pesticide properties database. Dataset is no longer available.
3 = Unverified data of known source
 Non-mobile
Koc
7660
Notes and range
Other sources: 316.2-15849 mL g⁻¹ (R3)
Freundlich
Kf
17
R4 R = Peer reviewed scientific publications
4 = Verified data
 Slightly mobile
Kfoc
580
1/n
0.95
Notes and range
Kf range 13.0-21.0 (229 for peat) mL g⁻¹, Kfoc range 491-636 (355 for peat) mL g⁻¹, 1/n - no data, Soils=4
pH sensitivity
-
Fate indices
Property
Value
Source; quality score; and other information
Interpretation
GUS leaching potential index
1.52 Calculated Low leachability
SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate
Value
3.32 X 10-02 Calculated -
Note
-
Potential for particle bound transport index
Medium Calculated -
Potential for loss via drain flow
Non-mobile Calculated -
Bio-concentration factor
BCF (l kg⁻¹)
40
P4 P = Other non-EU, UK or US Governments and Regulators
4 = Verified data
(Other literature values Log BCF range 1.1-1.9 (R3))		 Low potential
CT₅₀ (days)
<0.5 -
Known metabolites

None
ECOTOXICOLOGY
Terrestrial ecotoxicology
Property
Value
Source; quality score; and other information
Interpretation
Mammals - Acute oral LD₅₀ (mg kg⁻¹)
2
G4 G = Extension Toxicology network database EXTOXNET. Available online but no longer updated. (click here )
4 = Verified data
Rat		 High
Mammals - Short term dietary NOEL
(mg kg⁻¹)
-
L2 L = Pesticide manuals and hard copy reference books / other sources
2 = Unverified data of unknown source
Rat 2 year		 -
(ppm diet)
2 -
Mammals - Chronic 21d NOAEL (mg kg⁻¹ bw d⁻¹)
- - -
Birds - Acute LD₅₀ (mg kg⁻¹)
2.1
G4 G = Extension Toxicology network database EXTOXNET. Available online but no longer updated. (click here )
4 = Verified data
Anas platyrhynchos		 High
Birds - Short term dietary (LC₅₀/LD₅₀)
- - -
Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)
- - -
Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹)
> 267
L3 L = Pesticide manuals and hard copy reference books / other sources
3 = Unverified data of known source
Eisenia foetida		 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)
- - -
Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)
> 0.21
R4 R = Peer reviewed scientific publications
4 = Verified data
Apis mellifera		 High
Unknown mode acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)
> 0.175
F2 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment )
2 = Unverified data of unknown source
Apis mellifera 		High
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)
Harmful
Q2 Q = Miscellaneous data from online sources
2 = Unverified data of unknown source
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)
1.5
L3 L = Pesticide manuals and hard copy reference books / other sources
3 = Unverified data of known source
Oncorhynchus mykiss		 Moderate
Fish - Chronic 21 day NOEC (mg l⁻¹)
> 0.098
P3 P = Other non-EU, UK or US Governments and Regulators
3 = Unverified data of known source
Danio rerio		 Moderate
Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)
0.0025
L3 L = Pesticide manuals and hard copy reference books / other sources
3 = Unverified data of known source
Daphnia magna		 High
Aquatic invertebrates - Chronic 21 day NOEC (mg l⁻¹)
0.0001
P3 P = Other non-EU, UK or US Governments and Regulators
3 = Unverified data of known source
Daphnia magna		 High
Aquatic crustaceans - Acute 96 hour LC₅₀ (mg l⁻¹)
0.00011
F4 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment )
4 = Verified data
Americamysis bahia		 High
Sediment dwelling organisms - Acute 96 hour LC₅₀ (mg l⁻¹)
0.14
F3 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment )
3 = Unverified data of known source
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)
- - -
Algae - Acute 72 hour EC₅₀, growth (mg l⁻¹)
10.0
F4 F = U.S. EPA ECOTOX database / U.S. EPA pesticide fate database / Miscellaneous WHO documents / FAO data, IPCS INCHEM data (US EPA Databases Related to Pesticide Risk Assessment )
4 = Verified data
Scenedesmus subspicatus		 Moderate
Algae - Chronic 96 hour NOEC, growth (mg l⁻¹)
- - -
Mesocosm study data
NOEAEC mg l⁻¹
- - -
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)
2
G4 G = Extension Toxicology network database EXTOXNET. Available online but no longer updated. (click here )
4 = Verified data
Rat		 High
Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)
71.0
L3 L = Pesticide manuals and hard copy reference books / other sources
3 = Unverified data of known source
Rat		 -
Mammals - Inhalation LC₅₀ (mg l⁻¹)
0.03
L3 L = Pesticide manuals and hard copy reference books / other sources
3 = Unverified data of known source
Rat (aerosol)		 -
Other Mammal toxicity endpoints
- - -
ADI - Acceptable Daily Intake (mg kg⁻¹ bw day⁻¹)
0.0006
A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications )
5 = Verified data used for regulatory purposes
 -
ARfD - Acute Reference Dose (mg kg⁻¹ bw day⁻¹)
0.005
A5 A = EU regulatory and evaluation data as published by EC, EFSA (RAR, DAR & Conclusion dossiers), EMA (e.g. EU Annex III PIC DGD) (EU - Pesticides database; EFSA Scientific Publications )
5 = Verified data used for regulatory purposes
 -
AAOEL - Acute Acceptable Operator Exposure Level (mg kg⁻¹ bw day⁻¹)
- - -
AOEL - Acceptable Operator Exposure Level - Systemic (mg kg⁻¹ bw day⁻¹)
- - -
Dermal penetration studies (%)
- - -
Dangerous Substances Directive 76/464
List I; List II - -
Exposure Routes
Public
-
Occupational
-
MRLs
European
EU MRL pesticide database 
Great Britain
GB MRL Register 
Notes
-
Drinking Water Standards
EU Drinking Water standards: A1 waters: 0.001 mg l⁻¹, A2 waters 0.0025 mg l⁻¹, A3 waters: 0.005 mg l⁻¹
EU Directive for the protection of shelfish intended for human consumption: 100 µg l⁻¹
B5 B = UK CRD and ACP Evaluation Documents / and other DEFRA (UK) documents; Also Chemicals Regulation Division, Health and Safety Executive (HSE), UK (click here )
5 = Verified data used for regulatory purposes
UK EA QS database 2018		 -
Drinking Water MAC (μg l⁻¹)
- - -
Mammalian dose elimination route and rate
- - -
Health issues
Specific human health issues
Carcinogen
Genotoxic
Endocrine disruptor
?Possibly, status not identified
A0 A = Chromosome aberration (EFSA database)
0 = No data
;
B0 B = DNA damage/repair (EFSA database)
0 = No data
;
C0 C = Gene mutation (EFSA database)
0 = No data
;
D0 D = Genome mutation (EFSA database)
0 = No data
;
E1 E = Unspecified genotoxicity type (miscellaneous data source)
1 = Positive
?Possibly, status not identified
Reproduction / development effects Acetyl cholinesterase inhibitor Neurotoxicant
✓Yes, known to cause a problem
 No data found
XNo, known not to cause a problem
Respiratory tract irritant Skin irritant Skin sensitiser
✓Yes, known to cause a problem
✓Yes, known to cause a problem
XNo, known not to cause a problem
Eye irritant Phototoxicant  
✓Yes, known to cause a problem
 No data found  
General human health issues
Highly toxic
Possible brain toxicant
USEPA - possible human carcinogen
Handling issues
Property
Value and interpretation
General
IMDG Transport Hazard Class 6.1
CLP classification 2013
Health: H300, H311, H330, H372
Environment: H400, H410
WHO Classification
Ia (Extremely hazardous)
UN Number
UN2810
Waste disposal & packaging
Packaging Group I (great danger)
Shelf-life, storage, stability and reactivity
Chemically stable under standad ambient conditions
TRANSLATIONS
Language
Name
English
parathion-ethyl
French
parathion
German
Parathion
Danish
parathion
Italian
paration
Spanish
paratión
Greek
parathion
Polish
paration
Swedish
-
Hungarian
-
Dutch
parathion
Norwegian
-
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