| Chemical Abstract Number (CAS #) |
58899
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| Synonyms | Lindane |
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gamma-BHC | Hexachlorocyclohexane (gamma) | gamma-Benzenehexachloride | Cyclohexane, 1,2,3,4,5,6-hexachloro-, (1-alpha, 2-alpha,3-beta, 4-alpha, 5-alpha,
6-beta) | HCH-gamma |
| Analytical Methods |
EPA Method 505 |
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EPA Method 508 |
EPA Method 525 |
EPA Method 608 |
EPA Method 617 |
EPA Method 625 |
EPA Method 8080A |
EPA Method 8081 |
EPA Method 8250A |
| Molecular Formula | C6H6Cl6 |
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| Use | INSECTICIDE FOR FIELD CROPS CORN, WHEAT
INSECTICIDE FOR ORNAMENTALS, PASTURE, & FORAGE CROPS
INSECTICIDE FOR FORESTRY, TIMBER PROTECTION, & LIVESTOCK
INSECTICIDE FOR SOIL & SEED TREATMENT & VITICULTURE
Medication (Human: pediculicide, scabicide; Vet: ectoparasiticide)
Used in baits & seed treatments for rodent control.
Application rates: Range from 0.25 to 2.25 ounces/100 lb of seed for seed treatment; 0.1 to 2.06
lb/acre for foliar and soil treatment; 0.8 to 1.5 oz/50,000 cubic feet of greenhouse; 0.006 to 0.11
lb/gallon for bark; 0.023 to 3% sprays, dips, and dusts for indoor and animal treatment; <0.01
lb/1000 square feet for animal premises; <4 lb/1000 square feet (14.64% solutions) for wood, and
wooden structures; and 1% dust for human skin/clothing treatment (military use only).
Medication: pediculicide, scabicide
Medication (vet): ectoparasiticide
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| Consumption Patterns | INSECTICIDE USED ON WHEAT, 25%; INSECTICIDE USED ON OTHER FIELD
CROPS-EG, CORN, 25%; NON-AGRICULTURAL USES, 50% (1982)
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| Apparent Color | WHITE, CRYSTALLINE POWDER ; COLORLESS, CRYSTALLINE SOLID ;
NEEDLES FROM ALCOHOL
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| Odor | SLIGHT MUSTY ODOR ; SLIGHT AROMATIC ODOR ; Pure lindane is odorless.
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| Boiling Point | 323.4 DEG C AT 760 MM HG
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| Melting Point | 112.5 DEG C
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| Molecular Weight | 290.85
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| Density | 1.85
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| Sensitivity Data | VAPORS MAY IRRITATE EYES, NOSE, & THROAT.
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| Environmental Impact | Lindane is used as an insecticide on hardwood logs and lumber, seeds, vegetables and
fruits, woody ornamentals, hardwood forests, livestock and pets, and existing structures. When
released to water, lindane is not expected to volatilize significantly. Lindane released to acidic or
neutral water is not expected to hydrolyze significantly, but in basic water, significant hydrolysis
may occur (t1/2=95 hr at pH 9.3). Transport to the sediment should be slow and result
predominantly from diffusion rather than settling. Release of lindane to soil will most likely result
in volatilization and slow leaching of lindane to groundwater. Lindane in the atmosphere is likely
to be subject to rain-out and dry deposition. The estimated half-life for the reaction of vapor
phase lindane with atmospheric hydroxyl radicals is 1.63 days. Lindane may slowly biodegrade in
aerobic media and will rapidly degrade under anaerobic conditions. Lindane has been reported to
photodegrade in water in spite of the lack of a photoreactive center, but photolysis is not
considered to be a major environmental fate process. Lindane will bioconcentrate slightly in fish.
Monitoring data indicate that lindane is a contaminant in air, water, sediment, soil, fish and other
aquatic organisms, wildlife, food, and humans. Human exposure results primarily from food.
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| Environmental Fate | TERRESTRIAL FATE: As the sole carbon source, lindane was found to support the
growth of 71 of 147 microorganisms isolated from loamy sand. Chloride ion formation was noted
in these cultures. The extent of lindane biodegradation by these pure cultures was not given .
From moist, aerated soil, 62% of the lindane applied was recovered, and 3% of the applied (14)C
was released as (14)CO2 after 105 days. After 140 days, 17.8% of the applied (14)C was released
from submerged soil. As measured by gas-liquid chromatography, the loss of lindane from
submerged anaerobic soil was nearly quantitative, with only 4% of the applied lindane
recoverable . Six weeks following treatment of soil with lindane and submergence of the soil,
1,2,4-trichlorobenzene, 1,2,3,5- and/or 1,2,4,5-tetrachlorobenzene, 1,2,3,4-tetrachlorobenzene,
gamma-2,3,4,5,6-pentachlorocyclohex-1-ene and gamma-3,4,5,6-tetrachlorocyclohexene were
detected in the soil by GC. The absence of these products from sterilized soil treated with lindane
was cited as evidence that the lindane metabolites resulted from biodegradation . Incubation of
aerobic and anaerobic soil suspensions of lindane for three weeks resulted in the disappearance of
0 and 63.8% of the applied lindane, respectively . This result was said to indicate that anaerobic
degradation of lindane is more extensive than aerobic degradation . Agricultural loam plots
treated with 10 or 100 lb of lindane retained only 0.2% of the added lindane on the plots after 15
years regardless of the dosage applied . After 50 hr, 26% and 100% of the surface applied
lindane remained on Hatboro silt loam and Norfolk sandy loam, respectively(6). The resistance of
lindane on the sandy loam to volatilization was concluded to be due to the dryness of the soil.
From a moist soil surface, the lindane content decreased to 50% and 10% of the amount applied
after 6 hr and 6 days, respectively, while 50 hr after lindane application to dry soil, 88% of the
applied lindane remained(6). A mean Koc of 1080.9 was obtained from Koc determinations on
three soils(7). The average organic carbon content of the soils used was 13%(7). Based on this
moderate Koc value and a water solubility of 17 ppm(8), lindane is expected to leach slowly to
groundwater. The leaching of lindane from Gezira soil (38.8% sand, 34.7% silt, 26.2% clay
and 4.6% organic carbon) from the Sudan was slow(9). After 45 days, <50% of the applied
lindane had leached from the soil(9). Freundlich constants for lindane sorption and desorption
were determined for four systems as follows. Montmorillonite clay-distilled water: 1258.9 or both
sorption and desorption, Roselawn Cemetery water-sediment: 354.8 and 4.26, Cross Lake water-
sediment: 2238.7 and 4.26 for sorption and desorption, respectively. The high desorption constant
for the Cross Lake system was said to suggest a strong interaction between lindane and the
organic material in the samples, although the organic contents, 1.34% and 1.33% for the
Roselawn Cemetery and Cross Lake, respectively, of the two sediment samples were similar(10).
AQUATIC FATE: Hydrolysis rate constants of 7.5X10-3, 8.99X10-4, and 1.07X10-3 1/hr were
determined in surface water samples from a eutrophic pond in Texas, a dystrophic reservoir in
Louisiana and an oligotrophic rock quarry in Indiana, respectively . The corresponding
hydrolysis half-lives are 92, 771, and 648 hr for the TX, LA, and IN samples, respectively. The
hydrolysis reactions follow first-order kinetics. A temperature of 25 deg C was used and pH's
were 7.3 (LA), 7.8 (IN), and 9.3 (TX). First order aqueous photolysis of lindane was observed in
direct sunlight photolysis experiments. The rate constants were 4.1X10-3 (TX), 3.9X10-4 (LA),
and 4.5X10-4 1/hr (IN). The half-life values were 169 (TX), 1,791 (LA), and 1.540 hr (IN). The
relative rapidity of reaction in the TX water samples was attributed to its higher pH. The reaction
products of lindane hydrolysis were said to be more susceptible to photolysis than lindane .
After 16 weeks, <30% of the applied lindane remained in unsterilized natural waters in capped
bottles . Biodegradation was concluded to be responsible for this result, although it was unclear
to what extent hydrolysis may have contributed to the result . River, lake and groundwater
half-lives for lindane were estimated from degradation data in these bodies to be 3-30, 30-300,
and >300 days, respectively . The fate of lindane has been studied in a field experiment . The
role of particle transport in the transport of lindane to the sediment was found to be small
compared to diffusion . After 100 days, 75% of the lindane added was found in the water
column and sediment layer of the quarry. The water column contained more than 75% of this
amount . The volatilization half-life of lindane from water has been estimated to be 115 days .
Assuming a depth of 1 m, the volatilization half-life of lindane from water was estimated to be
191 days(6). A half-life of 3.2 days for the volatilization of lindane from 4.5 cm deep, still, pure
water at 24 deg C while with stirring, the half-life was 1.5 days(7). Using an equation relating
water depth to volatilization half-life(7), the experimental half-life of 3.2 days from 4.5 cm was
used to project a half-life of 692 days from a depth of 1 m. This figure is of the same order of
magnitude as the estimated half-lives of 115 and 191 days for volatilization from 1 m, so these
figures can be considered to be valid estimates of the tendency of lindane to volatilize.
ATMOSPHERIC FATE: The half-life of the reaction of lindane with hydroxyl radicals in the
atmosphere was estimated to be 1.63 days . Lindane removal rates in percent/week by rainfall
and dry deposition are 2.5 and 3.3, respectively, and the estimated residence time of lindane in the
atmosphere is 17 weeks .
Aquatic Fate : The fate of lindane in a very oligotrophic, lentic lake aquatic system was studied/.
Equal concentrations of lindane and DDE were added in late May to a flooded limestone quarry
and the pesticide concentrations in the water, sediment, and biota were monitored for a year's
time. The lake was thermally stratified during the summer, was intermittently covered with ice in
the winter, and received a large influx of sediment because of a rainstorm that occured one day
after the pesticides were introduced into the system Conclusions drawn indicate the following/:
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