Provenance

Reference data from EU CLP Annex VI and published regulations — verify against your supplier's SDS before use.

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Substance profile

Malathion

Malathion is a colorless or slightly yellow with a skunk-like odor.

CAS 121-75-5 Warning

01 · Identification

What Malathion is

Malathion is a colorless or slightly yellow with a skunk-like odor. It boils at 60 °C, melts at 3.9 °C.

Under the GHS it carries the signal word Warning.

CAS number121-75-5
EC number204-497-7
Index number015-041-00-X

Other names for Malathion

  • malathion (ISO)
  • 1,2-bis(ethoxycarbonyl)ethyl O,O-dimethyl phosphorodithioate
  • [containing ≤ 0.03 % isomalathion]

02 · GHS classification

Hazards and label elements

Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.

Signal wordWarning
Hazard statements assigned to Malathion
CodeHazard statement
H302 Harmful if swallowed.
H317 May cause an allergic skin reaction.
H400 Very toxic to aquatic life.
H410 Very toxic to aquatic life with long lasting effects.

Precautionary statements: P261, P270, P272, P273, P280, P301, P312, P313, P330, P333, P391, P501

03 · Physical and chemical properties

Malathion properties

Every value is shown with the conditions it was measured under and the source it came from. Where sources disagree, all values are listed rather than one being picked — the difference is usually a different form of the substance, not an error.

Property Value Conditions Source
Boiling point 60 °C (140 °F) decomposes NIOSH
156.5 °C (313.7 °F) range, midpoint shown, at 0.7 mmHg (reduced pressure) HSDB
Melting point 3.85 °C (38.9 °F) HSDB
2.78 °C (37 °F) NIOSH
2.83 °C (37.1 °F) CAMEO
Density 1.21 g/cm³ NIOSH
1.2076 g/cm³ at 20 °C HSDB
1.234 g/cm³ at 25 °C CAMEO
Solubility Soluble in ethanol, benzene and ethyl ether HSDB
In water, 143 mg/L at 20 °C at 20 °C HSDB
Vapor pressure 0.00004 mmHg NIOSH
0.0000397 mmHg at 30 °C HSDB
Flash point 163 °C (325.4 °F) ICSC
162.78 °C (325 °F) above this value HSDB
Lower explosive limit (LEL) Class IIIB Combustible Liquid: Fl.P. at or above 200 °F., but may be difficult to ignite. NIOSH
Above 100 °C, decomposes rapidly and explosion may be induced. decomposes HSDB
Vapor density 11.4 (air = 1) ICSC
Odor threshold 1.00 ppm (detection in water, purity not stated) HSDB
The odor threshold of malathion is very close (13.5 mg/cu m) to the OSHA PEL (15 mg/cu m) and may not provide adequate warning of hazardous concentrations. HSDB
Odor thresholds: 13.5 mg/cu m (low); 13.5 mg/cu m (high) HSDB
Corrosivity Corrosive to iron and some other metals HSDB
Malathion will attack some forms of plastics, rubber, and coatings HSDB
Corrosive to metals HSDB

Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.

04 · Source notes

Further notes on Malathion

These are descriptions rather than measured values, so they are kept out of the table above and quoted here with the source that reported them.

Solubility

Miscible with many organic solvents including alcohols, esters, ketones, ethers, aromatic and alkylated aromatic hydrocarbons and vegetable oils. Limited solubility in certain paraffin hydrocarbons

Source: HSDB

05 · Handling and storage

Storing and handling Malathion

Storage conditions

Keep container tightly closed in a dry and well-ventilated place. Containers which are opened must be carefully resealed and kept upright to prevent leakage. Recommended storage temperature 2 - 8 °C

Source: Hazardous Substances Data Bank (HSDB)

Incompatible materials

Incompatible materials: Strong oxidizing agents. Corrodes metal.

Source: Hazardous Substances Data Bank (HSDB)

Reactivity

MALATHION is a yellow to brown liquid that solidifies at 2.9 °C, moderately toxic. Organic phosphate insecticide, acts as an inhibitor of cholinesterase. When heated to decomposition it emits toxic fumes of oxides of sulfur and phosphorus [Lewis, 3rd ed., 1993, p. 789].

Source: CAMEO Chemicals

Planning storage for a mix of chemicals? Check Malathion in the storage compatibility matrix →

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