SPECTRUM

Chemical Fact Sheet

Chemical Abstract Number (CAS #) 319846
CASRN 319-84-6
Synonymsalpha-BHC
Cyclohexane, 1,2,3,4,5,6-hexachloro-, (1-alpha, 2-alpha,3-beta, 4-alpha, 5-beta, 6-beta)-
HCH-alpha
Analytical Methods EPA Method 508
EPA Method 608
EPA Method 617
EPA Method 625
EPA Method 8081
EPA Method 8270
Molecular FormulaC6H6Cl6

Link to the National Library of Medicine's Hazardous Substances
Database for more details on this compound.

Use COMPONENT OF BENZENE HEXACHLORIDE, BHC-FORMER INSECTICIDE /SRP, Former Use/: HCH is often used with DDT Hexachlorocyclohexane
Apparent Color MONOCLINIC PRISMS FROM ALCOHOL OR ACETIC ACID
Boiling Point 288 DEG C
Melting Point 159-160 DEG C
Molecular Weight 290.85
Density 1.87 AT 20 DEG C
Odor Threshold Concentration Detection in water for alpha-lindane of unspecified purity at 0.088 ppm
Sensitivity Data Symptoms of HCH poisoning are often delayed up to 3 hr. They include , respiratory difficulty. Other symptoms of HCH contact are skin irritation, skin sensitization, scabis and pediculosis. Hexachlorocyclohexane
Environmental Impact Small amounts of alpha-hexachlorocyclohexane (alpha-HCH) may result from the isomerization of lindane (gamma-HCH) upon exposure to sunlight. Release of alpha-HCH to the environment probabaly occurs mainly from the use of technical hexachlorocyclohexane as a pesticide. When released to water, alpha-HCH is not expected to volatilize or hydrolyze extensively. Release of alpha-HCH to the soil will most likely result in slow leaching to groundwater. Slow volatilization may also occur. Alpha-HCH entering the atmosphere, by analogy to lindane, may be subject to rain-out and dry deposition. The estimated half-life for the reaction of alpha-HCH with hydroxyl radicals in the atmosphere is 1.63 days. Biodegradation may occur slowly in aerobic surroundings and is expected to occur rapidly and extensively under anaerobic conditions. Alpha-HCH 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 process in its environmental fate. Alpha-HCH will bioconcentrate slightly in fish and other aquatic organisms. Monitoring data indicate that alpha-HCH is a contaminant in air, water, sediment, soil, fish and other aquatic organisms, foods, and humans. Human exposure results primarily from food.
Environmental Fate TERRESTRIAL FATE: After two weeks in unsterilized, submerged Casiguran sandy loam, the concentration of alpha-hexachlorocyclohexane (alpha-HCH) declined from about 16 ppm to <1 ppm compared to a decline from about 18 ppm to 15 ppm in a sterilized preparation . Fifteen years following the application of technical hexachlorocyclohexane to a sandy loam soil in Nova Scotia, Canada, 4% of the applied alpha-HCH remained in the soil . Of this amount, about 92% was found between 0-20 cm, indicating minimal leaching . The soil was under cultivation yearly throughout the fifteen years, increasing the likelihood that volatilization may have occurred . Incubation of aerobic and anaerobic soil suspensions of alpha-HCH for three weeks resulted in disappearence of 11.0% and 26.2% of the added compound, respectively . This result was said to indicate that anaerobic degradation is more extensive than aerobic biodegradation . AQUATIC FATE: No data on the rate of hydrolysis of alpha-hexachlorocyclohexane (alpha-HCH) is available. Hydrolysis half-lives of 92-771 hr have been reported for lindane in natural waters , however, and based on the relatively greater stability of alpha-HCH compared to lindane imparted by its smaller number of axial chlorines, it may hydrolyze more slowly than lindane. ATMOSPHERIC FATE: The half-life of the reaction of alpha-hexachlorocyclohexane (alpha-HCH) with hydroxyl radicals in the atmosphere was estimated to be 1.63 days . Dry deposition and rainfall have been found to remove atmospheric lindane at 3.3 and 2.5% per week, respectively . Alpha-HCH should also be subject to these processes.
Drinking Water Impact DRINKING WATER: Alpha-hexachlorocyclohexane (alpha-HCH) levels in municipal drinking water samples collected in January 1980 from 12 locations in Canada ranged from 2.7-20.3 ppt in winter and from 0.45-9.7 ppt in summer(7). Tap water from Ottawa, Ontario Canada contained 17 ppb alpha-HCH(8). GROUNDWATER: Samples from New Jersey taken during 1977-1979 ranged from ND-0.1 ppb, 15.7% of the samples were positive(9). Five subsurface water samples collected along the Niagara River from Lake Erie to Lake Ontario contained from small range < 0.005-0.007 ppb alpha-HCH(11). SURFACE WATER: Samples from New Jersey taken during 1977-1979 ranged from ND-0.8 ppb, 39% of the samples were positive(9). Samples from Washington, DC and Denver, CO were 20% positive and alpha-HCH concentrations ranged from 0.0027-0.1 ppb(10). 75 raw water samples collected at Niagara on the lake in 1980-1981 were 100% positive for alpha-HCH with mean and median concentrations of 10.5 and 9.7 ppt, respectively(12). RAIN/SNOW: Great Lakes ecosystem precipitation samples - 1-35 ppt, 15 ppt avg ; Enewetak Atoll rain samples - 3110 ng/cu m . Lake Superior (Isle Royale) - May-Oct 1983 rain samples, 19-65 ppt avg . Lake Superior (Caribou Island) - April-May 1983, 3.9-46 ppt mean . Canada (12 sites) - rain and frozen samples, April 1977 - Dec 1980, 75-100% pos, ND (< 0.001 ppb)-0.1300 ppb, 0.03 ppb avg . Great Lakes (Canadian side) - 49 rain samples, 59% pos, 11.7 ppt avg, 41 ppt max, 17 snow samples, 0.9 ppt avg . Portland, OR - southwest, rain samples, March - April 1982, 5.9 ppt avg, southeast, rain samples, Oct-Dec 1982, 47 ppt avg(6). EFFL: Alpha-hexachlorocyclohexane (alpha-HCH) residues in treated wastewater effluents from a variety of industries were as follows: coal mining- 47 samples, 6.4% positive, 0.10-2.2 ppb, 1.5 ppb avg; founderies-13 samples, 100% positive, 5-6 ppb, 5.1 ppb avg . In organic chemicals manufacturing/plastics, 3 of an unspecified number of samples contained a mean alpha-HCH concentration of 10 ppb .

DISCLAIMER - Please Read

Florida-Spectrum List of Services
Florida-Spectrum Homepage