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malathion (Ref: OMS 1)
** carbophos ** maldison ** mercaptothion ** carbofos ** ENT 17034 ** Translations

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Further data may be found in the VSDB


Malathion is an insecticide approved for use in the EU and in many other countries. It is moderately soluble in water and readily soluible 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 honey bees and aquatic species with the exception of algae. It is moderately toxic to birds and earthworms.

for malathion

Description: An insecticide and acaricide used to control a wide range of pests

Example pests controlled: Coleoptera; Diptera; Hemiptera; Lepidoptera; Mosquitoes; Fruit flies; Aphids; Mealybugs; Leaf hoppers; Spidermites

Example applications: Vegetables including turnips; Public health applications; Ornamental trees and shrubs; Stored produce

Availability status: Current

Introduction & key dates: 1952, first reported

EC Regulation 1107/2009 (repealing 91/414):
Status Approved
Dossier rapporteur/co-rapporteur Finland
Date inclusion expires 30/04/2020

Approved for use () or known to be used () in the following European countries:





























Also used in: USA

General status:
Pesticide type Insecticide, Acaricide, Veterinary substance
Substance group Organophosphate
Minimum active substance purity 950 g/kg (racemic mixture)
Known relevant impurities EU dossier - malaoxon <1g/kg, isomalathion <2g/kg, MeOOSPS-triester <15g/kg, MeOOOPS-triester 5g/kg
Substance origin Synthetic
Mode of action Broad-spectrum, non-systemic with contact, stomach and respiratory action. Acetylcholinesterase (AChE) inhibitor.
CAS RN 121-75-5
EC number 204-497-7
CIPAC number 12
US EPA chemical code 057701
Chiral molecule Chiral, a specific isomer or a derivative of a chiral molecule
Chemical formula C10H19O6PS2
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
Structure diagram/image available? Yes
Molecular mass (g mol-1) 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
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
Amblyseius fallacis
Aphis gossypii
Culex restuans
Aedes caspius
many more
Physical state Clear to amber liquid
Related substances & organisms

Property Value
Example manufacturers & suppliers of products using this active now or historically
  • Cheminova A/S
  • FMC Chemicals
  • Headland
  • Nickerson
  • American Cyanamid
  • Farmoplant
Example products using this active
  • Fyfanon 440
  • Karbofos
  • Cythion
  • Maltox
UK LERAP status None
Formulation and application details Often supplied as an emulsifiable concentrate, wettable powder or ULV.


for malathion

Property Value Source/Quality Score/Other Information Interpretation
Solubility - In water at 20oC (mg l-1) 148 A5 Moderate
Solubility - In organic solvents at 20oC (mg l-1) 250000 A5 - Xylene -
62000 A5 - Heptane -
250000 A5 - Acetone -
250000 A5 - Methanol -
Melting point (oC) -20 A5 -
Boiling point (oC) Decomposes before boiling A5 -
Degradation point (oC) 174 A5 -
Flashpoint (oC) 173 A5 -
Octanol-water partition coefficient at pH 7, 20oC P 5.62 X 1002 Calculated -
Log P 2.75 A5 Moderate
Bulk density (g ml-1)/Specific gravity 1.23 B5 -
Dissociation constant (pKa) at 25oC Not applicable B5 -
Note: No dissociation
Vapour pressure at 25oC (mPa) 3.1 A5 Volatile
Henry's law constant at 25oC (Pa m3 mol-1) 1.00 X 10-03 A5 Non-volatile
Henry's law constant at 20oC (dimensionless) 4.80 X 10-05 K3 Volatile
GUS leaching potential index -1.28 Calculated Low leachability
SCI-GROW groundwater index (μg l-1) for a 1 kg ha-1 or 1 l ha-1 application rate Value 3.12 X 10-05 Calculated -
Note -
Potential for particle bound transport index - Calculated Low
Maximum UV-vis absorption L mol-1 cm-1 No absorbance above 290nm A5 -
Surface tension (mN m-1) 58.0 A5 at 20oC -

Property Value Source/Quality Score/Other Information Interpretation
Soil degradation (days) (aerobic) DT50 (typical) 0.17 A5 Non-persistent
DT50 (lab at 20oC) 0.17 A5 Non-persistent
DT50 (field) 1 A5 Non-persistent
DT90 (lab at 20oC) 0.63 A5 -
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)
Plant matrix DT50 (days) Value 5.9 R4 -
Note DT50 range 0.02 - 114.0 days, 37 crops/plants, various matrices
Aqueous photolysis DT50 (days) at pH 7 Value 98 B5 Stable
Note DT50 156 days under test conditions - not natural light (A5)
Aqueous hydrolysis DT50 (days) at 20oC and pH 7 Value 6.2 A5 Non-persistent
Note pH sensitive: DT50 107 days at pH 5, 0.49 days at pH 9, all at 25 degC
Water-sediment DT50 (days) 0.4 A4 Fast
Water phase only DT50 (days) 0.4 A4 Fast

Soil adsorption and mobility:
Property Value Source/Quality Score/Other Information Interpretation
Linear Kd - DW2 Slightly mobile
Koc 1800
Notes and range -
Freundlich Kf 1.58 A5 Moderately mobile
Kfoc 217
1/n 0.94
Notes and range EU dossier kf range 0.83-2.47 mL/g, Kfoc range 151-308 mL/g, 1/n range 0.904-0.978, Soils=5
pH sensitivity No

Key metabolites:
Metabolite Formation medium Estimated maximum occurrence fraction 91/414 relevancy
malathion monocarboxylic acid (Ref: MMCA) Soil   0.25   Major fraction, Relevant
malathion dicarboxylic acid Soil   0.62   Major fraction, Relevant
isomalathion On heating     Relevant

Other known metabolites:
Metabolite name and reference Aliases Formation medium / Rate Estimated maximum occurrence fraction Metabolising enzymes
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) - -


for malathion

Property Value Source/Quality Score/Other Information Interpretation
Bio-concentration factor BCF (l kg-1) 103 A5 (Other literature Log BCF range 0-3.7 (R3)) Threshold for concern
CT50 (days) 0.69 -
Mammals - Acute oral LD50 (mg kg-1) 1778 A5 Rat Moderate
Mammals - Short term dietary NOEL (mg kg-1) 34.4 A5 Rat High
(ppm diet) - -
Birds - Acute LD50 (mg kg-1) 359 A5 Colinus virginianus Moderate
Birds - Short term dietary (LC50/LD50) 554 mg kg bw-1 day-1 A5 Colinus virginianus -
Fish - Acute 96 hour LC50 (mg l-1) 0.018 A5 Oncorhynchus mykiss High
Fish - Chronic 21 day NOEC (mg l-1) 0.091 A5 Oncorhynchus mykiss Moderate
Aquatic invertebrates - Acute 48 hour EC50 (mg l-1) 0.0007 A5 Daphnia magna High
Aquatic invertebrates - Chronic 21 day NOEC (mg l-1) 0.00006 A5 Daphnia magna High
Aquatic crustaceans - Acute 96 hour LC50 (mg l-1) 0.0015 F3 Americamysis bahia High
Sediment dwelling organisms - Acute 96 hour LC50 (mg l-1) 0.0004 F2 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) - - -
Non-target plants > 1800 A5, six species, Vegetative vigour, ER50, Vegetative vigour, ER50, as g/ha -
- - -
Algae - Acute 72 hour EC50, growth (mg l-1) 13 B5 Raphidocelis subcapitata, EU dossier EC50 = 4.1 Unknown species Low
Algae - Chronic 96 hour NOEC, growth (mg l-1) - - -
Honeybees Contact acute 48 hour LD50 (μg bee-1) 0.16 A5 High
Oral acute 48 hour LD50 (μg bee-1) 0.40 A5 High
Unknown mode acute 48 hour LD50 (μg bee-1) - - -
Earthworms - Acute 14 day LC50 (mg kg-1) 306 A5 Eisenia foetida, corr Moderate
Earthworms - Chronic 14 day NOEC, reproduction (mg kg-1) - - -
Other soil macro-organisms - e.g. Collembola LR50 / EC50 / NOEC / % Effect - - -
Other arthropod (1) LR50 g ha-1 0.061 48 hour
A5 Aphidius rhopalosiphi
% Effect - - -
Other arthropod (2) LR50 g ha-1 85.4 A5 Typhlodromus pyri -
% Effect - - -
Soil micro-organisms Nitrogen mineralisation: No significant adverse effect
Carbon mineralisation: No significant adverse effect
Dose: 6.3 kg ha-1
Mesocosm study data NOEAEC mg l-1 0.030 A5 Aquatic invertebrates -
NOEAEC mg l-1 - - -


for malathion

Property Value Source/Quality Score/Other Information Interpretation
Threshold of Toxicological Concern (Cramer Class) High (class III) - -
Mammals - Acute oral LD50 (mg kg-1) 1778 A5 Rat Moderate
Mammals - Dermal LD50 (mg kg-1 body weight) > 2000 A5 Rat -
Mammals - Inhalation LC50 (mg l-1) > 5.0 A5 Rat, 4 hr -
Other Mammal toxicity endpoints Intraperitoneal LD50 = 250 mg kg-1 V3 Rat -
Intravenous LD50 = 50 mg kg-1 V3 Rat -
ADI - Acceptable Daily Intake (mg kg-1bw day-1) 0.03 A5 Rat, SF=1000 -
ARfD - Acute Reference Dose (mg kg-1bw day-1) 0.3 A5 Rat, SF=100 -
AOEL - Acceptable Operator Exposure Level - Systemic (mg kg-1bw day-1) 0.03 A2 Rat, SF=1000 -
Dermal penetration studies (%) 5.0-15.0 A5 concentration dependant -
Dangerous Substances Directive 76/464 List I; List II - -
Exposure Limits [LT TWA 8hr: 10 mg/m3] MEL UK HSE -
Exposure Routes Public Possible concerns for bystanders especially children should they enter a sprayed area
Occupational Operators should use PPC/PPE at all times
European MRLs Click here for the EU MRL pesticide database
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 Possible adrenal gland, thyroid and liver toxicant
Acetylcholinesterase inhibition
IARC group 2A carcinogen; USEPA - some evidence to suggest possible human carcinogen

: 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 Prevent generation of mists
Store at low temperatures, do not heat
Not explosive or oxidising
IMDG Transport Code is usually 6.1
CLP classification 2013 -
EC Risk Classification Xn - Harmful: R22, R43
N - Dangerous for the environment: R50, R53
EC Safety Classification S2, S24, S37, S46, S60, S61
WHO Classification III - Slightly hazardous
US EPA Classification (formulation) III - Caution - Slightly toxic
UN Number Usually 2783
Waste disposal & packaging Packaging Group III (minor danger)


for malathion

Language Name
English malathion
French malathion
German Malathion
Danish malathion
Italian malation
Spanish malation
Greek malathion
Slovenian malation
Polish malation
Swedish -
Hungarian malathion
Dutch malathion

Record last updated: Monday 17 October 2016