Malathion

Synonyms

((Dimethoxyphosphinothioyl)thio)butanedioic acid diethyl ester; AC 26691; American cyanamid 4,049; Butanedioic acid, ((dimethoxyphosphinothioyl)-thio)-, diethyl ester, (+-)-; Butanedioic acid, ((dimethoxyphosphinothioyl)thio)-, diethyl ester; Camathion; Carbethoxy malathion; Carbetovur; Carbetox; Carbofos; Carbophos; Chemathion; Cimexan; Compound 4049; Cythion; Detmol MA; Dicarboethoxyethyl O,O-dimethyl phosphorodithioate; Diethyl ((dimethoxyphosphinothioyl)thio)butanedioate; Diethyl (+-)-mercaptosuccinate, S-ester with O,O-dimethyl phosphorodithioate; Diethyl (dimethoxyphosphinothioylthio)succinate; Diethyl mercaptosuccinate S-ester with O,O-dimethylphosphorodithioate; Diethyl mercaptosuccinate, O,O-dimethyl dithiophosphate, S-ester; Diethyl(dimethoxythiophosphorylthio)succinate; Dithiophosphate de O,O-dimethyle et de S-(1,2-dicarboethoxyethyle) [French]; Dorthion; EL 4049; Emmatos Extra; Ethiolacar; Etiol; Extermathion; Flair; Forthion; Fosfothion; Fosfotion; Fosfotion 550; Fyfanon; Hilthion; IFO 13140; Insecticide No. 4049; Karbofos; Kill-A-Mite; Kop-thion; Kypfos; Latka 4049 [Czech]; Malacide; Malafor; Malagran; Malakill; Malamar; Malamar 50; Malaphos; Malasol; Malaspray; Malataf; Malathiazol; Malathion E50; Malathion LV concentrate; Malathon; Malathyl; Malation [Polish]; Malatol; Malatox; Maldison; Malmed; Malphos; Mercaptosuccinic acid diethyl ester; Mercaptothion; Mercaptotion [Spanish]; Moscarda; O,O-Dimethyl S-(1,2-bis(ethoxycarbonyl)ethyl) dithiophosphate; O,O-Dimethyl S-(1,2-dicarbethoxyethyl) dithiophosphate; O,O-Dimethyl S-(1,2-dicarbethoxyethyl)phosphorodithioate; O,O-Dimethyl S-1,2-di(ethoxycarbamyl)ethyl phosphorodithioate; O,O-Dimethyl-S-1,2-(dicarbaethoxyaethyl)-dithiophosphat [German]; O,O-Dimethyl-S-1,2-dikarbetoxylethylditiofosfat [Czech]; O,O-Dimethyldithiophosphate diethylmercaptosuccinate; O,O-Dwumetylo-S-1,2-bis(karboetoksyetylo)-dwutiofosforan [Polish]; Oleophosphothion; Ortho malathion; Ovide; Paladin; Phosphorodithioic acid, O,O-dimethyl ester, S-ester with diethyl mercaptosuccinate; Phosphothion; Prioderm; S-(1,2-Bis(aethoxy-carbonyl)-aethyl)-O,O-dimethyl-dithiophosphat [German]; S-(1,2-Bis(carbethoxy)ethyl) O,O-dimethyl dithiophosphate; S-(1,2-Bis(ethoxy-carbonyl)-ethyl)-O,O-dimethyl-dithiofosfaat [Dutch]; S-(1,2-Bis(ethoxycarbonyl)ethyl) O,O-dimethyl phosphorodithioate; S-(1,2-Bis(etossi-carbonil)-etil)-O,O-dimetil-ditiofosfato [Italian]; S-(1,2-Di(ethoxycarbonyl)ethyl) dimethyl phosphorothiolothionate; S-(1,2-Dicarbethoxyethyl) O,O-dimethyldithiophosphate; S-(1,2-Dicarbethoxyethyl) O,O-dimethylphosphorodithioate; S-1,2-Bis(ethoxycarbonyl)ethyl-O,O-dimethyl thiophosphate; SF 60; Sadofos; Sadophos; Siptox I; Succinic acid, mercapto-, diethyl ester, S-ester with O,O-dimethyl phosphorodithioate; Sumitox; TAK; TM-4049; Taskil; [ChemIDplus]

Category

Organophosphate Insecticides

Description

Deep-brown to yellow liquid with a garlic-like odor. [insecticide]; [NIOSH]

Sources/Uses

Used on fruits and vegetables, and to control mosquitoes, flies, and animal parasites; Malathion is often used in mixtures with other pesticides. [EXTOXNET]

Comments

Malathion is one of the less potent organophosphate insecticides. It has an oral LD50 of 500-1000 mg/kg compared to an LD50 of 1-5 mg/kg for parathion. [LaDou, p. 584] Allergic contact dermatitis has been reported in farmers. [Kanerva, p. 1808] "Inhalation is not a significant route of exposure to malathion at ordinary temperatures because of its low volatility, but toxic effects can occur after inhalation of malathion sprays or dusts." [ATSDR Medical Management] “The average of two baseline respective cholinesterase activity determinations three days apart, with no exposures to enzyme inhibiting pesticides for at least 30 days, is recommended for each worker prior to exposure to cholinesterase inhibitors because of large inter-individual differences in published baseline values. To be established at least once a year. Removal from workplace exposures is recommended until the cholinesterase activity returns to within 20% of baseline.” [TLVs and BEIs]

Reference Link #1

Biomedical References

Acetylcholinesterase activity in red blood cells = 70% of individual's baseline; Butylcholinesterase activity in serum or plasma = 60% of individual's baseline; Sample at end of shift; [TLVs and BEIs]

Yes

1 mg/m3, inhalable fraction and vapor

15 mg/m3, total dust

15 mg/m3, inhalable fraction

250 mg/m3

Excerpts from Documentation for IDLHs

Human data: Workers exposed to initial concentrations up to 85 mg/m3 for 1 hour (that may have declined rapidly) over 42 consecutive days suffered no adverse effects [Golz 1959]. Workers exposed to concentrations that peaked at 56 mg/m3 and averaged 3.3 mg/m3 for 5 hours had normal cholinesterase levels [Culver et al. 1956]. A lethal oral dose of 246 to 471 mg/kg has been reported [Farago 1967; Jusic and Milic 1978]. [Note: An oral dose of 246 to 471 mg/kg is equivalent to a 70­kg worker being exposed to about 11,500 to 22,100 mg/m3 for 30 minutes, assuming a breathing rate of 50 liters per minute and 100% absorption.]

4E-05 mm Hg

Reference Link #2

Yes

Probable (2a)

Not Classifiable

Other Poison

Organophosphate

Diseases

Occupational diseases associated with exposure to this agent:

• Contact dermatitis, allergic
• Organophosphates & carbamates, acute poisoning

Processes

Industrial Processes with risk of exposure:

• Farming (Pesticides)