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Malathion (Ref: OMS 1)
Last updated: 21/08/2024
(Also known as: carbophos; maldison; mercaptothion; carbofos; ENT 17034)

SUMMARY
Malathion is a broad-spectrum insecticide. It is moderately soluble in water and readily soluble in many organic solvents. It is quite volatile and has a low potential for leaching to groundwater. Malathion is not usually persistent in soil or water systems. It is moderately toxic to mammals, a cholineserase inhibitor and a neurotoxin. Malathion is highly toxic to honeybees and aquatic species with the exception of algae. It is moderately toxic to birds and earthworms.
GENERAL INFORMATION
Description
An organophosphate insectide once used to control animal parasites
Availability status
Current
Introduction & key dates
1952, first reported
Examples of veterinary uses
Once used to control fleas, ticks, mites, lice and keds on a variety of animals
Examples of species treated
Cats; Dogs; Cattle; Sheep; Horses; Pigs
Approval status
VMR 2013/2033 approval status (GB/UK)
Not approved
EU Regulatory approval status
Not approved
Chemical structure
Isomerism
A chiral molecule existing as two enantiomers
Chemical formula
C₁₀H₁₉O₆PS₂
Canonical SMILES
CCOC(=O)CC(C(=O)OCC)SP(=S)(OC)OC
Isomeric SMILES
No data
International Chemical Identifier key (InChIKey)
JXSJBGJIGXNWCI-UHFFFAOYSA-N
International Chemical Identifier (InChI)
InChI=1S/C10H19O6PS2/c1-5-15-9(11)7-8(10(12)16-6-2)19-17(18,13-3)14-4/h8H,5-7H2,1-4H3
2D structure diagram/image available?
Yes
General status
Veterinary substance type
Insecticide, Antiparasitic
Substance groups
Organophosphate insectide; Organophosphate acaricide; Organothiophosphate insecticide; Organothiophosphate acaricide
Minimum active substance purity
950 g kg⁻¹ (racemic mixture)
Known relevant impurities
EU dossier - malaoxon <1g kg⁻¹, isomalathion <2g kg⁻¹, MeOOSPS-triester <15g kg⁻¹, MeOOOPS-triester 5g kg⁻¹
Substance origin
Synthetic
Mode of action
Broad-spectrum, non-systemic with contact, stomach and respiratory action. Acetylcholinesterase (AChE) inhibitor.
Molecular targets
[Cholinesterase, Inhibitor]
CAS RN
121-75-5
EC number
204-497-7
CIPAC number
12
US EPA chemical code
057701
PubChem CID
4004
CLP index number
015-041-00-X
Therapeutic Class
Antiparasitic products, insecticides & repellents: Ectoparasiticides
ATCvet Code
QP53AF12
Controlled Drug?
No
Regulation 37/2010 MRL Classification
-
Molecular mass
330.36
PIN (Preferred Identification Name)
-
IUPAC name
diethyl (dimethoxyphosphinothioylthio)succinate
CAS name
diethyl ((dimethoxyphosphinothioyl)thio)butanedioate
Other status information
Marine Pollutant; Evidence of use in third world countries; Chemical subject to PIC regulations; Phytotoxic to some ornamentals including orchids, ferns and petunias
Relevant Environmental Water Quality Standards
UK statutory standard for the protection of aquatic life in inland waters and for surface water quality: 0.01 µg l⁻¹ as annual average conc.
UK statutory standard for the protection of aquatic life in coastal and territorial waters: 0.02 µg l⁻¹ as annual average conc.
Physical state
Clear to amber liquid
Formulations
Property
Product
Manufacturer
Authorisation Route
Legal Class (GB/UK)
Example products (past and present) using this active
- - - -
Formulation and application details
-
ENVIRONMENTAL FATE
Property
Value
Source; quality score; and other information
Interpretation
Solubility - In water at 20 °C (mg l⁻¹)
148
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
Moderate
Solubility - In organic solvents at 20 °C (mg l⁻¹)
250000
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
Xylene
-
62000
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
Heptane
-
250000
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
Acetone
-
250000
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
Methanol
-
Melting point (°C)
-20
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
-
Boiling point (°C)
Decomposes before boiling
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
-
Degradation point (°C)
174
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
-
Flashpoint (°C)
173
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
-
Octanol-water partition coefficient at pH 7, 20 °C
P
5.62 X 1002 Calculated -
Log P
2.75
A4 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 )
4 = Verified data
at 25 °C
Moderate
Fat solubility of residues
Solubility
Insoluble
A4 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 )
4 = Verified data
-
Data type
Regulatory data
A4 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 )
4 = Verified data
-
Density (g ml⁻¹)
1.23
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
-
Dissociation constant pKa) at 25 °C
Not applicable
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
-
No dissociation
Vapour pressure at 20 °C (mPa)
3.1
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
Low volatility. If applied directly to plants or soil, drift is a concern & mitigation is advisable
Henry's law constant at 25 °C (Pa m³ mol⁻¹)
1.00 X 10-03
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
Non-volatile
Volatilisation as max % of applied dose lost
From plant surface
-
A4 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 )
4 = Verified data
16 day
-
From soil surface
6.0
A4 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 )
4 = Verified data
16 day
Volatilisation is not considered critical for air pollution
Maximum UV-vis absorption L mol⁻¹ cm⁻¹
No absorbance above 290nm
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
-
Surface tension (mN m⁻¹)
58.0
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
at 20°C
-
Refractive Index
- - -
Environmental release
-
Degradation
Property
Value
Source; quality score; and other information
Interpretation
Soil degradation (days) (aerobic)
DT₅₀ (typical)
0.17
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
Non-persistent
DT₅₀ (lab at 20 °C)
0.17
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
Non-persistent
DT₅₀ (field)
1
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
Non-persistent
DT₉₀ (lab at 20 °C)
0.63
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
Non-persistent
DT₉₀ (field)
- - -
Note
EU dossier lab studies range DT₅₀ 0.1-0.25 days, DT₉₀ range 0.3-0.84 days; Other sources: DT₅₀ 1.0 days (DW4)
Manure DT₅₀ (days)
- - -
Aqueous photolysis DT₅₀ (days) at pH 7
Value
98
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
Stable
Note
DT₅₀ 156 days under test conditions - not natural light (A5)
Aqueous hydrolysis DT₅₀ (days) at 20 °C and pH 7
Value
6.2
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
Non-persistent
Note
pH sensitive: DT₅₀ 107 days at pH 5, 0.49 days at pH 9, all at 25 °C
Water-sediment DT₅₀ (days)
0.4
A4 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 )
4 = Verified data
Fast
Water phase only DT₅₀ (days)
0.4
A4 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 )
4 = Verified data
Fast
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
[Wheat grain: 12 wks @ 30 DegC, 50% RH; Modelled data], [Malt: 1291 days @ 20-22 DegC, dark conditions; Field study], [Mushroom (Agaricus bisporus): 4.4 days @ 25 DegC; 8.9 days @ 4 DegC; 17.3 days @ -18 DegC; Lab study], [Maize grain: 27.3 wks, open basket storage, 37.3 wks, closed wooden box storage @ 23 DegC, Field study]. [Field beans: 37.0 wks, open basket storage, 57.9 wks, closed wooden box storage @ 23 DegC, Field study].
Soil adsorption and mobility
Property
Value
Source; quality score; and other information
Interpretation
Linear
Kd (mL g⁻¹)
-
DW2 DW = Don Wauchope personal database for Pka data: Wauchope, R. D. and Edwards, J. Dissociation constants for pesticide active ingredients: a database and comparison with predicted values. Dataset is no longer available.
2 = Unverified data of unknown source
Slightly mobile
Koc (mL g⁻¹)
1800
Notes and range
-
Freundlich
Kf (mL g⁻¹)
1.58
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
Moderately mobile
Kfoc (mL g⁻¹)
217
1/n
0.94
Notes and range
EU dossier kf range 0.83-2.47 mL g⁻¹, Kfoc range 151-308 mL g⁻¹, 1/n range 0.904-0.978, Soils=5
pH sensitivity
No
Fate indices
Property
Value
Source; quality score; and other information
Interpretation
GUS leaching potential index
0.00 Calculated Low leachability
Bio-concentration factor
BCF (l kg⁻¹)
103
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
(Other literature Log BCF range 0-3.7 (R3))
Threshold for concern
CT₅₀ (days)
0.69 -
Known soil metabolites
Metabolite
Major/Minor fraction
Estimated maximum occurrence fraction
Notes
malathion monocarboxylic acid (Ref: MMCA)
Major fraction 0.250 -
malathion dicarboxylic acid
Major fraction 0.617 -
Known groundwater metabolites

None

Other known metabolites
Metabolite name and reference
Aliases
Formation medium / Rate
Estimated maximum occurrence fraction
diethyl (2RS)-2-[(dimethoxyphosphoryl)sulfanyl]butanedioate
Note: Considerably more toxic than malathion
Malaoxon Plant; Animal -
desmethyl malathion DMM Plant -
malathion dicarboxylic acid DCA Human (Liver) -
malathion monocarboxylic acid DMA Human (Liver) -
isomalathion - On heating -
ECOTOXICOLOGY
Terrestrial ecotoxicology
Property
Value
Source; quality score; and other information
Interpretation
Mammals - Acute oral LD₅₀ (mg kg⁻¹)
1778
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
Rat
Moderate
Mammals - Short term dietary NOEL
(mg kg⁻¹)
34.4
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
Rat
High
(ppm diet)
- -
Mammals - Chronic 21d NOAEL (mg kg⁻¹ bw d⁻¹)
- - -
Birds - Acute LD₅₀ (mg kg⁻¹)
359
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
Colinus virginianus
Moderate
Birds - Short term dietary (LC₅₀/LD₅₀)
554 mg kg bw⁻¹ day⁻¹
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
Colinus virginianus
-
Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)
- - -
Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹)
306
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
Eisenia foetida corr
Moderate
Earthworms - Chronic NOEC, reproduction (mg kg⁻¹)
- - -
Soil micro-organisms
Nitrogen mineralisation: No significant adverse effect
Carbon mineralisation: No significant adverse effect
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

Dose: 6.3 kg ha⁻¹
-
Collembola
Acute LC₅₀ (mg kg⁻¹)
- - -
Chronic NOEC (mg kg⁻¹)
- - -
Non-target plants
> 1800
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
six species
Vegetative vigour, ER₅₀
as g ha⁻¹
-
- - -
Honeybees (Apis spp.)
Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)
0.16
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
Apis mellifera
High
Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)
0.40
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
Apis mellifera
High
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)
0.0005
R4 R = Peer reviewed scientific publications
4 = Verified data
Megachile rotundata
High
Mode of exposure
Contact
Other bee species (2)
Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)
0.265
R4 R = Peer reviewed scientific publications
4 = Verified data
Trigona spinipes
High
Mode of exposure
Contact
Beneficial insects (Ladybirds)
- - -
Beneficial insects (Lacewings) as Mortality, Contact ppm
> 111.1
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
Chrysoperla carnea Larva
-
Beneficial insects (Parasitic wasps) as Mortality LR₅₀ g ha⁻¹ 48 hr
0.061
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
Aphidius rhopalosiphi
-
Beneficial insects (Predatory mites) as Mortality LR₅₀ g ha⁻¹ 7 day
85.4
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
Typhlodromus pyri
-
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)
0.018
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
Oncorhynchus mykiss
High
Temperate Freshwater Fish - Chronic 21 day NOEC (mg l⁻¹)
0.091
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
Oncorhynchus mykiss
Moderate
Tropical Freshwater Fish - Acute 96 hour LC₅₀ (mg l⁻¹)
> 0.027
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
Danio rerio Eggs
High
Temperate Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)
0.0007
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
Daphnia magna
High
Temperate Freshwater Aquatic invertebrates - Chronic 21 day NOEC (mg l⁻¹)
0.00006
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
Daphnia magna
High
Tropical Freshwater Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)
> 0.002
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
Ceriodaphnia dubia LC₅₀
High
Aquatic crustaceans - Acute 96 hour LC₅₀ (mg l⁻¹)
0.0015
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
Americamysis bahia
High
Sediment dwelling organisms - Acute 96 hour LC₅₀ (mg l⁻¹)
0.0004
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
Chironomus riparius 1 day
High
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)
13
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
Raphidocelis subcapitata EU dossier EC₅₀ = 4.1 Unknown species
Low
Algae - Chronic 96 hour NOEC, growth (mg l⁻¹)
- - -
Mesocosm study data
NOEAEC mg l⁻¹
0.030
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
Aquatic invertebrates
-
NOEAEC mg l⁻¹
- - -
Marine bivalves
- - -
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)
1778
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
Rat
Moderate
Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)
2000
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
Rat
-
Mammals - Inhalation LC₅₀ (mg l⁻¹)
> 5.0
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
Rat 4 hr
-
Other Mammal toxicity endpoints
Intraperitoneal LD₅₀ = 250 mg kg⁻¹
V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID )
3 = Unverified data of known source
Rat
-
Intravenous LD₅₀ = 50 mg kg⁻¹
V3 V = ChemID Online Databases; Chemspider; PubChem. (ChemID )
3 = Unverified data of known source
Rat
-
ADI - Acceptable Daily Intake (mg kg⁻¹ bw day⁻¹)
0.03
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
Rat SF=1000
-
ARfD - Acute Reference Dose (mg kg⁻¹ bw day⁻¹)
0.3
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
Rat SF=100
-
AAOEL - Acute Acceptable Operator Exposure Level (mg kg⁻¹ bw day⁻¹)
- - -
AOEL - Acceptable Operator Exposure Level - Systemic (mg kg⁻¹ bw day⁻¹)
0.03
A2 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 )
2 = Unverified data of unknown source
Rat SF=1000
-
Dermal penetration studies (%)
5.0-15.0
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
concentration dependent
-
Dangerous Substances Directive 76/464
List I; List II - -
Exposure Routes
Public
Possible concerns for bystanders especially children should they enter a sprayed area
Occupational
Operators should use PPC/PPE at all times
Mammalian dose elimination route and rate
Mainly excreted as metabolites in the urine
Q3 Q = Miscellaneous data from online sources
3 = Unverified data of known source
-
Health issues
Specific human health issues
Carcinogen
Genotoxic
Endocrine disruptor
?Possibly, status not identified
A2 A = Chromosome aberration (EFSA database)
2 = Mixed/ambiguous results
;
B3 B = DNA damage/repair (EFSA database)
3 = Negative
;
C3 C = Gene mutation (EFSA database)
3 = Negative
;
D0 D = Genome mutation (EFSA database)
0 = No data
;
E2 E = Unspecified genotoxicity type (miscellaneous data source)
2 = Mixed/ambiguous results
Yes, known to cause a problem
Reproduction / development effects Acetyl cholinesterase inhibitor Neurotoxicant
?Possibly, status not identified
Yes, known to cause a problem
Yes, known to cause a problem
Respiratory tract irritant Skin irritant Skin sensitiser
?Possibly, status not identified
?Possibly, status not identified
?Possibly, status not identified
Eye irritant Phototoxicant  
XNo, known not to cause a problem
No data found  
General human health issues
Possible adrenal gland, thyroid and liver toxicant
Acetylcholinesterase inhibition
IARC group 2A carcinogen; US EPA - weak evidence to suggest possible human carcinogen
Endocrine issues - Inhibition of catecholamine secretion
Handling issues
Property
Value and interpretation
General
Prevent generation of mists
Store at low temperatures, do not heat
Not explosive or oxidising
IMDG Transport Hazard Class 6.1
CLP classification 2013
Health: H302, H317
Environment: H400, H410
WHO Classification
III (Slightly hazardous)
UN Number
UN3018
Waste disposal & packaging
Packaging Group II (moderate danger)
Shelf-life, storage, stability and reactivity
-
TRANSLATIONS
Language
Name
English
malathion
French
malathion
German
Malathion
Danish
malathion
Italian
malation
Spanish
malation
Greek
malathion
Polish
malation
Swedish
-
Hungarian
malathion
Dutch
malathion
Norwegian
-

Record last updated: 21/08/2024
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