Synonyms: Succinic acid, mercapto- , diethyl ester, S-ester with O,O-dimethylphosphorodithioate; O,O-Dimethyldithiophosphate diethylmercaptosuccinate; O,O-Dimethyl S-(1,2-bis(ethoxycarbonyl) ethyl) dithiophosphate; S-1,2-bis(ethoxycarbonyl)ethyl-O,O-dimethyl thiophosphate; Maldison

OSHA IMIS Code Number: 1616

IMIS Name History: Malathion prior to 9/1/89

Chemical Abstracts Service (CAS) Registry Number: 121-75-5

NIOSH Registry of Toxic Effects of Chemical Substances (RTECS) Identification Number: WM8400000

Department of Transportation Regulation Number (49 CFR 172.101) and Guide: 2783 152

NIOSH Pocket Guide to Chemical Hazards, Malathion: chemical description, physical properties, potentially hazardous incompatibilities, and more

OSHA Permissible Exposure Limit (PEL):

General Industry: 29 CFR 1910.1000 Z-1 Table -- 15 mg/m3 TWA; Skin

Construction Industry: 29 CFR 1926.55 Appendix A -- 15 mg/m3 TWA; Skin

Maritime: 29 CFR 1915.1000 Table Z-Shipyards -- 15 mg/m3 TWA; Skin

American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV): 1 mg/m³ TWA - Inhalable fraction, Vapor and aerosol; Skin; Appendix A4 - Not Classifiable as a Human Carcinogen; BEI - Appendix A: Carcinogens

National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Limit (REL):10 mg/m³ TWA; Skin

Carcinogenic Classification:

International Agency for Research on Cancer (IARC): Group 3, not classifiable as to its carcinogenicity to humans [98 KB PDF, 37 pages]

NIOSH Immediately Dangerous To Life or Health Concentration (IDLH): 250 mg/m³

Potential Symptoms: Irritation of eyes, skin; miosis, aching eyes, blurred vision, lacrimation, salivation; anorexia; nausea, vomiting, abdominal cramps, diarrhea; dizziness, confusion; ataxia; rhinorrhea; headache; tightness of chest, wheezing, laryngeal spasm; low blood pressure; skin sensitization; personality changes, irritability; muscle spasms, paralysis; convulsions, coma.

Health Effects: Cholinesterase inhibition (HE6)

Affected Organs: Eyes, skin, respiratory system, liver, blood cholinesterase, CNS, cardiovascular system, GI tract.

Notes:

1. The measurement of blood acetylcholinesterase can serve as a nonspecific biomarker of exposure. Symptoms of intoxication usually appear at 60-70% inhibition of this enzyme.
2. Malathion is activated by cytochrome P-450 to malaoxon. Other metabolites, malathion monocarboxylic acid and malathion dicarboxylic acid are excreted in the urine and used as specific biomarkers of occupational exposure.

Literature Basis:

• NIOSH Pocket Guide to Chemical Hazards: Malathion.
• International Chemical Safety Cards (WHO/IPCS/ILO): Malathion.
• Bouchard, M, Gosselin, N.H., Brunet, R.C., Samuel, O., Dumoulin, M.-J. and Carrier, G.: A toxicokinetic model of malathion and its metabolites as a tool to assess human exposure and risk through measurements of urinary biomarkers. Toxicol. Sci. 73(1): 182-194, 2003.
• Pohanish, R.P. (editor): Malathion. In, Sittig's Handbook of Toxic and Hazardous Chemicals and Carcinogens, Fourth Ed., Vol. 2. Norwich, NY: Noyes Publications, William Andrew Publishing, 2002, pp. 1433-1436.

Date Last Revised: 06/18/2004

Laboratory Sampling/Analytical Method:

• sampling media: OSHA Versatile Sampler (OVS-2) - 13 mm XAD-2 tube (270/140 mg sections, 20/60 mesh) with Glass Fiber Filter enclosed
  analytical solvent: Toluene
  maximum volume: 60 Liters   maximum flow rate: 1.0 L/min
  current analytical method: Gas Chromatography; GC/FPD
  method reference: OSHA Analytical Method (OSHA 62)
  method classification: Fully Validated
  note: OSHA personnel may obtain sampling tubes from the Salt Lake Technical Center.

Wipe Sampling Method:

• sampling media: Glass Fiber Filter

Bulk Method:

• Limit the amount of bulk submitted to one gram or one mL.

** All Trademarks are the property of their respective owners.