Heptachlor
Names | |
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Preferred IUPAC name
1,4,5,6,7,8,8-Heptachloro-3a,4,7,7a-tetrahydro-1H-4,7-methanoindene | |
Identifiers | |
3D model (
JSmol ) |
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ChEBI | |
ChEMBL | |
ChemSpider | |
ECHA InfoCard
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100.000.876 |
KEGG | |
PubChem CID
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UNII | |
CompTox Dashboard (EPA)
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Properties | |
C10H5Cl7 | |
Molar mass | 373.32 g/mol |
Appearance | White to tan solid |
Odor | Camphorous |
Density | 1.58 g/cm3 |
Melting point | 95 to 96 °C (203 to 205 °F; 368 to 369 K) |
Boiling point | 135 to 145 °C (275 to 293 °F; 408 to 418 K) at 1-1.5 mmHg |
0.0006% (20°C)[1] | |
Vapor pressure | 0.0003 mmHg (25°C)[1] |
Hazards | |
Flash point | noncombustible[1] |
Lethal dose or concentration (LD, LC): | |
LD50 (median dose)
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116 mg/kg (oral, guinea pig) 40 mg/kg (oral, rat) 100 mg/kg (oral, rat) 68 mg/kg (oral, mouse) 100 mg/kg (oral, hamster)[2] |
LDLo (lowest published)
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50 mg/kg (cat, oral)[2] |
LCLo (lowest published)
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150 mg/m3 (cat, 4 hr) 200 mg/m3 (mammal, 4 hr)[2] |
NIOSH (US health exposure limits): | |
PEL (Permissible)
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TWA 0.5 mg/m3 [skin][1] |
REL (Recommended)
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Ca TWA 0.5 mg/m3 [skin][1] |
IDLH (Immediate danger) |
Ca [35 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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Heptachlor is an
Synthesis
Analogous to the synthesis of other cyclodienes, heptachlor is produced via the
Compared to chlordane, it is about 3–5 times more active as an insecticide, but more inert chemically, being resistant to water and caustic alkalies.[4]
Metabolism
Soil
Environmental impact
Heptachlor is a
Heptachlor epoxide is more likely to be found in the environment than its parent compound. The epoxide also dissolves more easily in water than its parent compound and is more persistent. Heptachlor and its epoxide absorb to soil particles and evaporate.[6]
The range of oral rat LD50 values are 40 mg/kg to 162 mg/kg. Daily oral doses of heptachlor at 50 and 100 mg/kg were found to be lethal to rats after 10 days. For heptachlor epoxide, the oral LD50 values ranging from 46.5 to 60 mg/kg. With rat oral of LD5047mg/kg, heptachlor epoxide is more toxic. A product of hydrogenation of heptachlor, β-dihydroheptachlor, has high insecticidal activity and low mammalian toxicity, rat oral LD50>5,000mg/kg.[4]
Human impact
Humans may be exposed to heptachlor through drinking water and foods, including breast milk.[6] Heptachlor epoxide is derived from a pesticide that was banned in the U.S. in the 1980s. It is still found in soil and water supplies and can turn up in food.[citation needed] It can be passed along in breast milk.[citation needed]
The
The U.S. EPA
An ATSDR report in 1993 found no studies with respect to death in humans after oral exposure to heptachlor or heptachlor epoxide.
Chemical properties
The octanol-water partition coefficient (Kow) of heptachlor is ~105.27. Henry's Law constant is 2.3 · 10−3atm-m3/mol and the vapor pressure is 3 · 10−4mmHg at 20 °C.[7][8]
References
- ^ a b c d e f NIOSH Pocket Guide to Chemical Hazards. "#0311". National Institute for Occupational Safety and Health (NIOSH).
- ^ a b c "Heptachlor". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH). 4 December 2014. Retrieved 27 March 2015.
- ^ a b c d Plimmer, J. R., ed. (2003). The Encyclopedia of Agrochemicals, Volume 3. New York: John Wiley & Sons.
- ^ a b California Environmental Protection Agency (1999). Public Health Goal for Heptachlor and Heptachlor Epoxide In Drinking Water - Office of Environment Health Hazard Assessment, California Environmental Protection Agency. "Archived copy" (PDF). Archived from the original (PDF) on 2009-05-04. Retrieved 2013-12-19.
{{cite web}}
: CS1 maint: archived copy as title (link) (retrieved on April 04, 2009). - ^ a b c ATSDR, (2007). Heptachlor and Heptachlor Epoxide - Fact Sheet [1].
- ISBN 978-1-4289-0041-7.
- ^ Harmon, Katherine 2010 New Mass-Screening Method Finds Additional Environmental Risks for Diabetes. Scientific American, May 21, 2010.
External links
- ASTDR ToxFAQs for Heptachlor
- CDC - NIOSH Pocket Guide to Chemical Hazards
- Heptachlor in the Pesticide Properties DataBase (PPDB)