(Also known as: Rhei radix; rhubarb root extract; Chinese rhubarb root powder)
Hazard alerts
The following Pesticide Hazard Tricolour (PHT) 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. The alerts for Highly Hazardous Pesticides (HHPs) are based on applying the FAO/WHO (Type 1) and the PAN (Type II) criteria to PPDB data. Further details on the HHP indicators are given in the tables below. Neither the PHT nor the HHP hazard alerts take account of usage patterns or exposure, thus they do not represent risk.
PHT: Environmental fate
PHT: Ecotoxicity
PHT: Human health
Highly Hazardous Pesticide
Human health Moderate alert: Genotoxic
GENERAL INFORMATION
Description
A plant-derived bio-fungicide with strong and protective action against various fungal diseases
Example pests/issues controlled
Powdery mildew; Various molds and other fungal diseases
No UK approval for use as a plant protection agent
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
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
Not applicable
Chemical formula
-
Canonical SMILES
-
Isomeric SMILES
-
International Chemical Identifier key (InChIKey)
-
International Chemical Identifier (InChI)
-
2D structure diagram/image available?
No
General status
Biopesticide type
Fungicide
Substance groups
Plant-derived substance
Minimum active substance purity
-
Known relevant impurities
-
Substance origin
Natural; Complex mixture
Mode of action
Non-systemic with residual activity. Contains oxalic acid and various phenolic compounds (e.g. chrysophanol, parietin) which inhibit the metabolism of fungi cells and thereby prevents the growth of the mycelia
Substance source
Extract from an asian rhubarb plant ( Rheum palmatum)
Mixture composition
The composition of Rheum officinale extract is dominated by emodin type anthraquinones (1-10% depending on the extent of the concentration and intended end use), with lesser amounts of tannins, phenolic acids and carbohydrates. Anthraquinones, particularly emodin, chrysophanol and physcion, are the key bioactive substances.
Uses
Crop protection
Farming system suitability
Suitable for IPM and traditional farming systems where approved for use
Example manufacturers & suppliers of products using this active now or historically
Onze Livre BV
Beijing Kingbo Boteck
Example products using this active
Formulation and application details
Field-ready formulations may be blended with microbial agents like Bacillus subtilis to create hybrid liquid products for foliar spraying or root irrigation. Liquid concentrates and powders are also available.
Commercial production
Rheum officinale extract is commercially produced through a multi-step process that preserves its bioactive compounds. First, mature rhubarb roots are harvested, cleaned, and dried under controlled conditions to prevent degradation of key constituents like anthraquinones, flavonoids, and tannins. The dried material is then ground into a fine powder and subjected to solvent extraction, commonly using ethanol or water, to isolate the desired phytochemicals. This extract is filtered to remove impurities, concentrated under reduced pressure, and finally dried into either a powder or liquid form depending on its intended application.
Impact on climate of production and use
-
ENVIRONMENTAL FATE
Property
Value
Source; quality score; and other information
Interpretation
Solubility - In water at 20 °C at pH 7 (mg l⁻¹)
-
-
-
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
-
-
-
Log P
-
-
-
Fat solubility of residues
Solubility
-
-
-
Data type
-
-
-
Density (g ml⁻¹)
-
-
-
Dissociation constant pKa) at 25 °C
-
-
-
-
Vapour pressure at 20 °C (mPa)
-
-
-
Henry's law constant at 25 °C (Pa m³ mol⁻¹)
-
-
-
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)
DT₅₀ (typical)
-
-
-
DT₅₀ (lab at 20 °C)
-
-
-
DT₅₀ (field)
-
-
-
DT₉₀ (lab at 20 °C)
-
-
-
DT₉₀ (field)
-
-
-
DT₅₀ modelling endpoint
-
-
-
Note
-
Soil mineralisation
Aerobic (at 20 °C)
-
-
-
Anaerobic (at 20 °C)
-
-
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
-
-
-
Note
-
Aqueous hydrolysis DT₅₀ (days) at 20 °C and pH 7
Value
-
-
-
Note
-
Water-sediment DT₅₀ (days)
-
-
-
Water phase only DT₅₀ (days)
-
-
-
Sediment 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)
-
-
-
Koc (mL g⁻¹)
-
Notes and range
-
Freundlich
Kf (mL g⁻¹)
-
-
-
Kfoc (mL g⁻¹)
-
1/n
-
Notes and range
-
pH sensitivity
-
Known metabolites
None
ECOTOXICOLOGY
Terrestrial ecotoxicology
Property
Value
Source; quality score; and other information
Interpretation
Mammals - Acute oral LD₅₀ (mg kg⁻¹)
> 5000
E4 E = Manufacturers safety data sheets 4 = Verified data
Rat
Low
Mammals - Short Term Oral NOAEL (mg kg⁻¹ bw d⁻¹)
-
-
-
Mammals - Long Term (Chronic) Oral NOAEL (mg kg⁻¹ bw d⁻¹)
-
-
-
Birds - Acute LD₅₀ (mg kg⁻¹)
-
-
-
Birds - Short term dietary LC₅₀ (mg kg⁻¹ bw d⁻¹)
-
-
-
Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)
-
-
-
Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹ dw soil)
-
E4 E = Manufacturers safety data sheets 4 = Verified data
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
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Human health
