Agent Name

Parathion

CAS Number

56-38-2

Formula

C10-H14-N-O5-P-S

Major Category

Pesticides

Synonyms

O,O-Diethyl-O-(p-nitrophenyl) phosphorothioate; Diethyl parathion; Ethylparathion; Parathion-ethyl; AC 3422; Alkron; Alleron; Aphamite; Corothion; E-605; Etilon; Fosferno 50; Niran;Orthophos; Panthion; Paramar; Paraphos; Parathene; Parawet; Phoskil; Rhodiatox; Soprathion; Stathion; Thiophos;

Category

Organophosphate Insecticides

Description

Pale-yellow to dark-brown liquid with a garlic-like odor. [Note: A solid below 43 degrees F.] [NIOSH]

Sources/Uses

In the U.S. parathion may be used only by licensed applicators on alfalfa, barley, corn, cotton, sorghum, soybeans, sunflowers, and wheat. [EXTOXNET]

Comments

Classified as "highly toxic," parathion has an LD50 in rats of 2 to 30 mg/kg; [EXTOXNET] A small number of the organophosphates (OPs) can Induce Delayed Neuropathy (OPIDN). OPIDN usually occurs after ingestion and is usually nonoccupational. [Levy, p. 431] "Toxic inhalation of parathion vapor is unlikely at ordinary temperatures because of its low volatility, but toxic effects can occur after inhalation of parathion 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]

Restricted

Use on fruit, nut and vegetable crops cancelled by EPA in 1992; [EXTOXNET]

Reference Link

EXTOXNET PIP - PARATHION

Exposure Assessment
BEI

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]

Skin Designation (ACGIH)

Yes

TLV (ACGIH)

0.05 mg/m3, inhalable fraction and vapor

PEL (OSHA)

0.1 mg/m3

MAK

0.1 mg/m3, inhalable fraction

IDLH (NIOSH)

10 mg/m3

Vapor Pressure

4.0E-5 mm Hg

Reference Link

ATSDR Medical Management - Parathion

Adverse Effects
Neurotoxin

Motor Neuropathy

Other Poison

Organophosphate

IARC Carcinogen

Not Classifiable

ACGIH Carcinogen

Not Classifiable

Links to Other NLM Databases
Health Studies

Human Health Effects from Hazardous Substances Data Bank:

Toxicity Information

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Chemical Information

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Biomedical References

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Related Information in HazMap
Diseases

Occupational diseases associated with exposure to this agent:

Processes

Industrial Processes with risk of exposure: