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DDT

DDT
Chemical structure of DDT
DDT-from-xtal-3D-balls.png
DDT-from-xtal-3D-vdW.png
Names
Preferred IUPAC name
1,1'-(2,2,2-Trichloroethane-1,1-diyl)bis(4-chlorobenzene)
Identifiers
50-29-3 YesY
3D model (Jmol) Interactive image
ChEBI CHEBI:16130 YesY
ChEMBL ChEMBL416898 N
ChemSpider 2928 YesY
ECHA InfoCard 100.000.023
KEGG D07367 YesY
PubChem 3036
UNII CIW5S16655 YesY
Properties
C14H9Cl5
Molar mass 354.48 g·mol−1
Density 0.99 g/cm3
Melting point 108.5 °C (227.3 °F; 381.6 K)
Boiling point 260 °C (500 °F; 533 K) (decomposes)
25 μg/L (25 °C)
Hazards
Main hazards Toxic, dangerous to the environment, likely carcinogenic
Toxic T Dangerous for the Environment (Nature) N
R-phrases R25 R40 R48/25 R50/53
S-phrases (S1/2) S22 S36/37 S45 S60 S61
NFPA 704
Flammability code 2: Must be moderately heated or exposed to relatively high ambient temperature before ignition can occur. Flash point between 38 and 93 °C (100 and 200 °F). E.g., diesel fuel Health code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g., chloroform Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
Flash point 72–77 °C; 162–171 °F; 345–350 K
Lethal dose or concentration (LD, LC):
LD50 (median dose)
 113–800 mg/kg (rat, oral)
250 mg/kg (rabbit, oral)
135 mg/kg (mouse, oral)
150 mg/kg (guinea pig, oral)
US health exposure limits (NIOSH):
PEL (Permissible)
 TWA 1 mg/m3 [skin]
REL (Recommended)
 Ca TWA 0.5 mg/m3
IDLH (Immediate danger)
 500 mg/m3
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YesYN ?)
Infobox references
External audio
Radical DDT.JPG
"Episode 207: DDT", Chemical Heritage Foundation

Dichlorodiphenyltrichloroethane (DDT) is a colorless, crystalline, tasteless, and almost odorless organochlorine known for its insecticidal properties and environmental impacts. First synthesized in 1874, DDT's insecticidal action was discovered by the Swiss chemist Paul Hermann Müller in 1939. It was used in the second half of World War II to control malaria and typhus among civilians and troops. After the war, DDT was also used as an agricultural insecticide and its production and use duly increased. Müller was awarded the Nobel Prize in Physiology or Medicine "for his discovery of the high efficiency of DDT as a contact poison against several arthropods" in 1948.

In 1962, Rachel Carson's book Silent Spring was published. It cataloged environmental impacts that coincided with widespread use of DDT in agriculture in the United States, and it questioned the logic of broadcasting potentially dangerous chemicals into the environment with little prior investigation of their environment and health effects. The book claimed that DDT and other pesticides had been shown to cause cancer and that their agricultural use was a threat to wildlife, particularly birds. Its publication was a seminal event for the environmental movement and resulted in a large public outcry that eventually led, in 1972, to a ban on DDT's agricultural use in the United States. A worldwide ban on agricultural use was formalized under the , but its limited and still-controversial use in disease vector control continues, because of its effectiveness in reducing malarial infections, balanced by environmental and other health concerns.

Along with the passage of the Endangered Species Act, the United States ban on DDT is a major factor in the comeback of the bald eagle (the national bird of the United States) and the peregrine falcon from near-extinction in the contiguous United States.


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Wikipedia

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