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IUPAC name
Other names
3D model (JSmol)
ECHA InfoCard 100.005.652
EC Number 206-215-8
RTECS number IO2100000
UN number 2762, 2761
Molar mass 364.90 g·mol−1
Appearance colorless solid
Density 1.60 g/mL[1]
Melting point 104 °C (219 °F; 377 K)
slightly soluble (0.003%)[1]
Vapor pressure 7.5 × 10−5 mmHg @ 20 °C
Main hazards potential occupational carcinogen[1]
GHS pictograms The skull-and-crossbones pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)The health hazard pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)The environment pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)
GHS signal word Danger
H300, H301, H301, H310, H311, H351, H372, H400, H410
P201, P202, P260, P262, P264, P270, P273, P280, P281, P301+310, P302+350, P302+352, P308+313, P310, P312, P314, P321, P322, P330, P361, P363, P391, P405, P501
NFPA 704
Flammability (red): no hazard codeHealth code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g., chloroformReactivity (yellow): no hazard codeSpecial hazards (white): no codeNFPA 704 four-colored diamond
Flash point 66 °C (151 °F; 339 K)
Lethal dose or concentration (LD, LC):
50 mg/kg (rabbit, oral)
33 mg/kg (guinea pig, oral)
39 mg/kg (rat, oral)
44 mg/kg (mouse, oral)[2]
5.8 mg/m3 (rat, 4 hr)[2]
US health exposure limits (NIOSH):
PEL (Permissible)
TWA 0.25 mg/m3 [skin][1]
REL (Recommended)
Ca TWA 0.25 mg/m3 [skin][1]
IDLH (Immediate danger)
25 mg/m3[1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Aldrin is an organochlorine insecticide that was widely used until the 1990s, when it was banned in most countries. It is a colourless solid. Before the ban, it was heavily used as a pesticide to treat seed and soil. Aldrin and related "cyclodiene" pesticides (a term for pesticides derived from Hexachlorocyclopentadiene) became notorious as persistent organic pollutants.[3]


Aldrin is produced by combining hexachlorocyclopentadiene with norbornadiene in a Diels-Alder reaction to give the adduct.[4]

Synthesis of aldrin via a Diels-Alder reaction

Similarly, an isomer of aldrin, known as isodrin, is produced by reaction of hexachloronobornadiene with cyclopentadiene.[5]

Aldrin is named after the German chemist Kurt Alder, one of the coinventors of this kind of reaction. An estimated 270 million kilograms of aldrin and related cyclodiene pesticides were produced between 1946 and 1976.

In soil, on plant surfaces, or in the digestive tracts of insects, aldrin oxidizes to the epoxide dieldrin, which is more strongly insecticidal.

Environmental impact and regulation[edit]

Like related polychlorinated pesticides, aldrin is highly lipophilic. Its solubility in water is only 0.027 mg/L, which exacerbates its persistence in the environment. It was banned by the Stockholm Convention on Persistent Organic Pollutants. In the U.S., aldrin was cancelled in 1974. The substance is banned from use for plant protection by the EU.[6]

Safety and environmental aspects[edit]

Aldrin has rat LD50 of 39 to 60 mg/kg (oral in rats). For fish however, it is extremely toxic, with an LC50 of 0.006 – 0.01 for trout and bluegill.[3]

In the US, aldrin is considered a potential occupational carcinogen by the Occupational Safety and Health Administration and the National Institute for Occupational Safety and Health; these agencies have set an occupational exposure limit for dermal exposures at 0.25 mg/m3 over an eight-hour time-weighted average.[7] Further, an IDLH limit has been set at 25 mg/m3, based on acute toxicity data in humans to which subjects reacted with convulsions within 20 minutes of exposure.[8]

It is classified as an extremely hazardous substance in the United States as defined in Section 302 of the U.S. Emergency Planning and Community Right-to-Know Act (42 U.S.C. 11002), and is subject to strict reporting requirements by facilities which produce, store, or use it in significant quantities.[9]


  1. ^ a b c d e f g h "NIOSH Pocket Guide to Chemical Hazards #0016". National Institute for Occupational Safety and Health (NIOSH). 
  2. ^ a b "Aldrin". Immediately Dangerous to Life and Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH). 
  3. ^ a b Robert L. Metcalf "Insect Control" in Ullmann’s Encyclopedia of Industrial Chemistry" Wiley-VCH, Weinheim, 2002. doi:10.1002/14356007.a14_263
  4. ^ Jubb, A. H. (1975). Basic Organic Chemistry, Part 5 Industrial products. London: Wiley. ISBN 0-471-85014-4. 
  5. ^ Bird, C. W.; Cookson, R. C.; Crundwell, E. (1961). "946. Cyclisations and rearrangements in the isodrin?aldrin series". Journal of the Chemical Society (Resumed): 4809. doi:10.1039/JR9610004809. 
  6. ^ Chemicals Regulation Directorate. "Banned and Non-Authorised Pesticides in the United Kingdom". Retrieved 1 December 2009. 
  7. ^ Centers for Disease Control and Prevention (4 April 2011). "Aldrin". NIOSH Pocket Guide to Chemical Hazards. Retrieved 13 November 2013. 
  8. ^ Centers for Disease Control and Prevention (May 1994). "Aldrin". Documentation for Immediately Dangerous To Life or Health Concentrations (IDLHs). Retrieved 13 November 2013. 
  9. ^ "40 C.F.R.: Appendix A to Part 355—The List of Extremely Hazardous Substances and Their Threshold Planning Quantities" (PDF) (July 1, 2008 ed.). Government Printing Office. Retrieved October 29, 2011.