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Pyraclonil (Ref: NAI-1886)
Last updated: 24/07/2024
(Not known by any other names)

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:
Moderately persistent; GUS: Transition state; Drainflow: Moderately mobile; Potential for particle bound transport: Medium
Ecotoxicity
Moderate alert:
Fish acute ecotoxicity: Moderate; Daphnia acute ecotoxicity: Moderate; Bees acute oral ecotoxicity: Moderate
Human health
High alert:
Carcinogen
Warning:
Significant data are missing
GENERAL INFORMATION
Description
A herbicide used for preemergence and early post emergence control of weeds in rice crops
Example pests controlled
Water hyacinth (Monochoria vaginalis); Chinese arrowhead (Sagittaria triflolia); Sedges; Barnyardgrass; Watergrass
Example applications
Paddy rice
Efficacy & activity
-
Availability status
-
Introduction & key dates
2007, first registered
UK regulatory status
UK COPR regulatory status
Not approved
Date COPR inclusion expires
Not applicable
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
Not applicable
Date EC 1107/2009 inclusion expires
Not applicable
EU Candidate for substitution (CfS)
Not applicable
Listed in EU database
No
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
Japan, USA
Chemical structure
Isomerism
None
Chemical formula
C₁₅H₁₅ClN₆
Canonical SMILES
CN(CC#C)C1=C(C=NN1C2=NN3CCCCC3=C2Cl)C#N
Isomeric SMILES
-
International Chemical Identifier key (InChIKey)
IHHMUBRVTJMLQO-UHFFFAOYSA-N
International Chemical Identifier (InChI)
InChI=1S/C15H15ClN6/c1-3-7-20(2)15-11(9-17)10-18-22(15)14-13(16)12-6-4-5-8-21(12)19-14/h1,10H,4-8H2,2H3
2D structure diagram/image available?
Yes
General status
Pesticide type
Herbicide
Substance groups
Nitrile herbicide; Pyrazole herbicide
Minimum active substance purity
>98%
Known relevant impurities
-
Substance origin
Synthetic
Mode of action
Broad spectrum. Inhibition of protoporphyrinogen oxidase (PPO) - cell membrane disruption
CAS RN
158353-15-2
EC number
805-557-0
CIPAC number
None allocated
US EPA chemical code
-
PubChem CID
11563984
CLP index number
No data found
Molecular mass
314.77
PIN (Preferred Identification Name)
1-(3-chloro-4,5,6,7-tetrahydropyrazolo[1,5-a]pyridin-2-yl)-5-[methyl(prop-2-yn-1-yl)amino]-1H-pyrazole-4-carbonitrile
IUPAC name
1-(3-chloro-4,5,6,7-tetrahydropyrazolo[1,5-a]pyridin-2-yl)-5-[methyl(prop-2-ynyl)amino]pyrazole-4-carbonitrile
CAS name
1-(3-chloro-4,5,6,7-tetrahydropyrazolo[1,5-a]pyridin-2-yl)-5-(methyl-2-propynylamino)-1H-pyrazole-4-carbonitrile
Other status information
-
Relevant Environmental Water Quality Standards
-
Herbicide Resistance Class (HRAC MoA class)
E
Herbicide Resistance Class (WSSA MoA class)
14
Insecticide Resistance Class (IRAC MoA class)
Not applicable
Fungicide Resistance Class (FRAC MOA class)
Not applicable
Examples of recorded resistance
-
Physical state
-
Formulations
Property
Value
Example manufacturers & suppliers of products using this active now or historically
  • Sumitomo Chemical Co.
  • Kyoyu Agri Co Ltd.
  • Nichino America, Inc
Example products using this active
  • Megazeta
Formulation and application details
Usually formulated as granules. Where approved, it may be applied aerially.
ENVIRONMENTAL FATE
Property
Value
Source; quality score; and other information
Interpretation
Solubility - In water at 20 °C (mg l⁻¹)
50.1
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
Moderate
Solubility - In organic solvents at 20 °C (mg l⁻¹)
- - -
Melting point (°C)
- - -
Boiling point (°C)
- - -
Degradation point (°C)
- - -
Flashpoint (°C)
- - -
Octanol-water partition coefficient at pH 7, 20 °C
P
1.51 X 1002 Calculated -
Log P
2.18
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
Low
Fat solubility of residues
Solubility
- - -
Data type
- - -
Density (g ml⁻¹)
1.34
Q2 Q = Miscellaneous data from online sources
2 = Unverified data of unknown source
-
Dissociation constant pKa) at 25 °C
- - -
-
Vapour pressure at 20 °C (mPa)
7.1 X 10-03
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
Low volatility
Henry's law constant at 25 °C (Pa m³ mol⁻¹)
1.2 X 10-11
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-volatile
Volatilisation as max % of applied dose lost
From plant surface
- - -
From soil surface
- - -
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)
44
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
Moderately persistent
DT₅₀ (lab at 20 °C)
44
P3 P = Other non-EU, UK or US Governments and Regulators
3 = Unverified data of known source
Moderately persistent
DT₅₀ (field)
- - -
DT₉₀ (lab at 20 °C)
- - -
DT₉₀ (field)
- - -
DT₅₀ modelling endpoint
- - -
Note
US EPA data: Lab studies DT₅₀ values ranging from 8.4 – 76 days under aerobic conditions
Dissipation rate RL₅₀ (days) on plant matrix
Value
- - -
Note
-
Dissipation rate RL₅₀ (days) on and in plant matrix
Value
- - -
Note
-
Aqueous photolysis DT₅₀ (days) at pH 7
Value
104
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
Stable
Note
Corrected for summer sunlight at 35 N
Aqueous hydrolysis DT₅₀ (days) at 20 °C and pH 7
Value
Stable
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
Stable
Note
Stable at pH 4, 7 and 9
Water-sediment DT₅₀ (days)
- - -
Water phase only DT₅₀ (days)
- - -
Air degradation
As this parameter is not normally measured directly, a surrogate measure is used: ‘Photochemical oxidative DT₅₀’. Where data is available, this can be found in the Fate Indices section below.
Decay in stored produce DT₅₀
-
Soil adsorption and mobility
Property
Value
Source; quality score; and other information
Interpretation
Linear
Kd (mL g⁻¹)
7.6
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
Moderately mobile
Koc (mL g⁻¹)
345
Notes and range
US EPA data Kf range 2.24-15.2 mL g⁻¹, Koc range 163-733 mL g⁻¹, Soils =10
Freundlich
Kf (mL g⁻¹)
- - -
Kfoc (mL g⁻¹)
-
1/n
-
Notes and range
-
pH sensitivity
-
Fate indices
Property
Value
Source; quality score; and other information
Interpretation
GUS leaching potential index
2.40 Calculated Transition state
SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate
Value
1.33 X 10-01 Calculated -
Note
-
Potential for particle bound transport index
Medium Calculated -
Potential for loss via drain flow
Moderately mobile Calculated -
Photochemical oxidative DT₅₀ (hrs) as indicator of long-range air transport risk
- - -
Bio-concentration factor
BCF (l kg⁻¹)
Low risk
Q3 Q = Miscellaneous data from online sources
3 = Unverified data of known source
Based on LogP < 3
Low risk
CT₅₀ (days)
- -
Known soil metabolites

None

Known groundwater metabolites
Metabolite
EC SANCO/221/2000 relevancy
ADI (mg kg⁻¹ bodyweight day⁻¹)
WHO drinking water guidance value (μg L⁻¹ day⁻¹)
1-(3-chloro-4,5,6,7-tetrahydropyrazolo[1,5-alpha]pyridin-2-yl)-5-(methylamino)-1H-pyrazole-4-carboxamide (Ref: pyraclonil M-6)
Unknown relevancy - -
1-(3-chloro-4,5,6,7-tetrahydropyrazolo[1,5-alpha]pyridin-2-yl)-5-(methyl(prop-2-enyl)amino)-1H-pyrazole-4-carbonitrile (Ref: pyraclonil M-11)
Unknown relevancy - -
1-(3-chloro-4,5,6,7-tetrahydropyrazolo[1,5-alpha]pyridin-2-yl)-5-(methyl(prop-2-yn-1-yl)amino)-1H-pyrazole-4-carboxamide (Ref: amidepyraclonil)
Unknown relevancy - -
Other known metabolites
Metabolite name and reference
Aliases
Formation medium / Rate
Estimated maximum occurrence fraction
1-(3-chloro-4,5,6,7-tetrahydropyrazolo[1,5-alpha]pyridin-2-yl)-5-(methylamino)-1H-pyrazole-4-carbonitrile
Note: US EPA data
pyraclonil M-1 Aqueous photolysis >0.100
1-(3-chloro-4,5,6,7-tetrahydropyrazolo[1,5-alpha]pyridin-2-yl)-5-(methyl(prop-2-enyl)amino)-1H-pyrazole-4-carbonitrile
Note: US EPA data
pyraclonil M-11 Surface water >0.100
1-(3-chloro-4,5,6,7-tetrahydropyrazolo[1,5-alpha]pyridin-2-yl)-5-(methylamino)-1H-pyrazole-4-carboxamide
Note: US EPA data
pyraclonil M-6 Surface water >0.100
5-amino-1-(3-chloro-4,5,6,7-tetrahydropyrazolo[1,5-alpha]pyridin-2-yl)-1H-pyrazole-4-carboxamide
Note: US EPA data
pyraclonil M-7a Surface water <0.100
1-(3-chloro-4-hydroxy-4,5,6,7-tetrahydropyrazolo[1,5-alpha]pyridin-2-yl)-5-(methylamino)-1H-pyrazole-4-carbonitrile
Note: US EPA data
pyraclonil M-7b Aqueous photolysis <0.100
N-(1-(3-chloro-4,5,6,7-tetrahydropyrazolo[1,5-a]pyridin-2-yl)-4-cyano-1H-pyrazol-5-yl)-N-methylformamide
Note: US EPA data
pyraclonil methylformamide Surface water <0.100
5-amino-1-(3-chloro-4,5,6,7-tetrahydropyrazolo[1,5-alpha]pyridin-2-yl)-1H-pyrazole-4-carbonitrile
Note: US EPA data
- Surface water <0.100
11-(3-chloro-4-hydroxy-4,5,6,7-tetrahydropyrazolo[1,5-alpha]pyridin-2-yl)-5-(methyl(prop-2-yn-1-yl)amino)-1H-pyrazole-4-carbonitrile
Note: US EPA data
4-hydroxy-pyraclonil Surface water <0.100
4-(4'-chloro-4-cyano-5-(methylamino)-1'H-[1,3'-bipyrazol]-5'-yl)butanoic acid
Note: US EPA data
pyraclonil VIII Surface water <0.100
1-(3-chloro-4-hydroxy-4,5,6,7-tetrahydropyrazolo[1,5-alpha]pyridin-2-yl)-5-(methylamino)-1H-pyrazole-4-carbonitrile
Note: US EPA data
pyraclonil PM-5 Surface water <0.100
ECOTOXICOLOGY
Terrestrial ecotoxicology
Property
Value
Source; quality score; and other information
Interpretation
Mammals - Acute oral LD₅₀ (mg kg⁻¹)
> 877
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
Mouse
Moderate
Mammals - Short term dietary NOEL
(mg kg⁻¹)
- - -
(ppm diet)
- -
Mammals - Chronic 21d NOAEL (mg kg⁻¹ bw d⁻¹)
- - -
Birds - Acute LD₅₀ (mg kg⁻¹)
> 2160
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
Colinus virginianus
Low
Birds - Short term dietary (LC₅₀/LD₅₀)
- - -
Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)
- - -
Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹)
- - -
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)
> 100
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
Apis mellifera
Low
Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)
> 44.0
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
Apis mellifera
Moderate
Unknown mode acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)
- - -
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)
- - -
Beneficial insects (Ground beetles)
- - -
Aquatic ecotoxicology
Property
Value
Source; quality score; and other information
Interpretation
Temperate Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)
6.0
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
Oncorhynchus mykiss
Moderate
Temperate Freshwater Fish - Chronic 21 day NOEC (mg l⁻¹)
- - -
Tropical Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)
23.05
R4 R = Peer reviewed scientific publications
4 = Verified data
Danio rerio
Moderate
Temperate Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)
15.09
R4 R = Peer reviewed scientific publications
4 = Verified data
Daphnia magna
Moderate
Temperate Freshwater Aquatic invertebrates - Chronic 21 day NOEC (mg l⁻¹)
- - -
Tropical Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)
- - -
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)
- - -
Sediment dwelling organisms - Chronic 28 day NOEC, sediment (mg kg⁻¹)
- - -
Aquatic plants - Acute 7 day EC₅₀, biomass (mg l⁻¹)
0.0062
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
Lemna minor
High
Algae - Acute 72 hour EC₅₀, growth (mg l⁻¹)
- - -
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)
> 877
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
Mouse
Moderate
Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)
- - -
Mammals - Inhalation LC₅₀ (mg l⁻¹)
- - -
Other Mammal toxicity endpoints
- - -
ADI - Acceptable Daily Intake (mg kg⁻¹ bw day⁻¹)
- - -
ARfD - Acute Reference Dose (mg kg⁻¹ bw day⁻¹)
- - -
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
- - -
Exposure Routes
Public
Not expected to be hazardous to residents or bystanders when used as directed
Occupational
-
MRLs
European
EU MRL pesticide database 
Great Britain
GB MRL Register 
Notes
-
Drinking Water Standards
- - -
Drinking Water MAC (μg l⁻¹)
- - -
Mammalian dose elimination route and rate
- - -
Health issues
Specific human health issues
Carcinogen
Genotoxic
Endocrine disruptor
Yes, known to cause a problem
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
;
E0 E = Unspecified genotoxicity type (miscellaneous data source)
0 = No data
No data found
Reproduction / development effects Acetyl cholinesterase inhibitor Neurotoxicant
?Possibly, status not identified
No data found No data found
Respiratory tract irritant Skin irritant Skin sensitiser
Yes, known to cause a problem
Yes, known to cause a problem
No data found
Eye irritant Phototoxicant  
Yes, known to cause a problem
No data found  
General human health issues
Possible liver and thyroid toxicant
EPA data: Likely to be Carcinogenic to Humans
Handling issues
Property
Value and interpretation
General
No information available
CLP classification 2013
Health: H302, H315, H319, H335
Environment: H400
WHO Classification
Not listed (Not listed)
UN Number
-
Waste disposal & packaging
-
Shelf-life, storage, stability and reactivity
-
TRANSLATIONS
Language
Name
English
pyraclonil
French
-
German
-
Danish
-
Italian
-
Spanish
-
Greek
-
Polish
-
Swedish
-
Hungarian
-
Dutch
-
Norwegian
-

Record last updated: 24/07/2024
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