121-75-5 Insecticides Malathion 95%TC 25%WP 50%WP 40%EC 50%EC 57%EC
CAS #: 121-75-5
Common name: malathion; maldison; malathon; mercaptothion;
IUPAC name: diethyl (dimethoxythiophosphorylthio)succinate;
S-1,2-bis(ethoxycarbonyl)ethyl O,O-dimethyl phosphorodithioate
Chemical Abstracts name: diethyl
Composition: Tech. grade is c. 95% pure.
Mol. wt.: 330.3; M.f.: C10H19O6PS2;
Form: Tech. is a clear, amber liquid.
M.p.: 2.85C; B.p.: 156-157C/0.7 mmHg.
V.p.: 5.3 mPa (30C).
KOW: logP = 2.75;
Henry: 1.21x10-2 Pa m3 mol-1 (calc.)
S.g./density: 1.23 (25C).
Solubility: In water 145 mg/l (25C). Miscible with most organic
solvents, e.g. alcohols, esters, ketones, ethers, aromatic
hydrocarbons. Slightly soluble in petroleum ether and some types of
Stability: Relatively stable in neutral, aqueous media. Decomposed
by strong acids and by alkali; hydrolysis DT50 107 d (pH 5), 6 d
(pH 7), 0.5 d (pH 9) (all 25C).
F.p.: 163C (Pensky-Martens closed cup).
1L bottle, 5L bottle, 20L bottle or 200L drum
Malathion is a low toxicity, broad-spectrum insecticide, and
miticide with contact and stomach toxicity. It also has the
function of fumigation. It is fast-acting and high efficient.
Malathion can be used for prevention and treatment of rice, wheat,
cotton, vegetables, tea, fruit tree pests such as aphids,
planthoppers, rice leafhoppers, rice thrips, Ping borer, scale
insects, red spider, gold shells, leaf miner, leaf-hop insects,
cotton leaf-roller moth, stick insects, vegetables borer, tea
leafhopper, fruit borer.
Malathion is widely used in agriculture and horticulture and can
also be used for family.
Buff transparent liquid
Emulsion dilution stability(200 times)
Up to FAO standard
Biochemistry: Cholinesterase inhibitor; proinsecticide, activated
by metabolic oxidative desulfuration to the corresponding oxon.
Mode of action: Non-systemic insecticide and acaricide with
contact, stomach, and respiratory action.
Uses: Used to control Coleoptera, Diptera, Hemiptera, Hymenoptera
and Lepidoptera in a wide range of crops, including cotton, pome,
soft and stone fruit, potatoes, rice and vegetables. Used
extensively to control major arthropod disease vectors (Culicidae)
in public health programmes, ectoparasites (Diptera, Acari,
Mallophaga) of cattle, poultry, dogs and cats, human head and body
lice (Anoplura), household insects (Diptera, Orthoptera), and for
the protection of stored grain. Typical application rates for
agricultural uses 0.5-1.25 kg/ha.
Phytotoxicity: Non-phytotoxic in general, if used as recommended,
but glasshouse cucurbits and beans, certain ornamentals, and some
varieties of apple, pear, and grape may be injured.
Formulation types: DP; EC; EW; UL; WP.ULV
Compatibility: Incompatible with alkaline materials (residual
toxicity may be decreased).
Oral: Acute oral LD50 for rats 1375-5500 mg/kg (pure), mice
Skin and eye: Acute percutaneous LD50 (24 h) for rabbits 4100-8800,
rats >2000 mg/kg.
Inhalation: LC50 (4 h) for rats >5.2 mg/l.
NOEL: In 2 y trials on rats, the only effects seen at 500 ppm (29
mg/kg b.w. daily) was inhibition of cholinesterase in plasma and
red blood cells.
ADI: 0.3 mg/kg b.w.
Toxicity class: WHO (a.i.) III; EPA (formulation) III (Fyfanon
tech. and 5 EC)
EC hazard: Xn; R22
Birds: Dietary LC50 (5 d) for bobwhite quail 3500, ring-necked
pheasants 4320 mg/kg diet.
Fish: LC50 (96 h) for bluegill sunfish 0.1, largemouth bass 0.28
Daphnia: EC50 (48 h) 1.0 ug/l.
Algae: EC50 (72 h) 13 mg/l.
Bees: Toxic to bees. LD50 (topical) 0.71 ug/bee.
Worms: LC50 613 mg/kg soil.
Animals: In mammals, following oral administration, the major part
of the dose is excreted in the urine and faeces within 24 hours.
Degradation is by oxidative desulfuration by liver microsomal
enzymes, leading to the formation of malaoxon; malathion and
malaoxon are hydrolysed and thus detoxified by carboxylesterases.
In insects, metabolism involves hydrolysis of the carboxylate and
phosphorodithioate esters, and oxidation to malaoxon.
Plants: De-esterified to its mono- and di- carboxylic acids, which
are cleaved to yield succinic acid, which is subsequently
incorporated into plant constituents.
Soil/Environment: Under normal conditions, it is 99% degraded by
hydrolysis within 7 d.