3,3',4,4',6,6'-ヘキサクロロビフェニル

... Dry sand or earth should be spread on the leak, or spill area. ...

Survey reports six case histories employing EPA's hazardous materials spills treatment trailer are reviewed. The trailer's ... treatment system has three mixed-media filters and three activated carbon columns to remove suspended, precipitated, and organic soluble materials. Spills of PCB, pentachlorophenol, kepone, termide (chlordane), heptachlor, aldrin, and dieldrin, toxaphene, and dinitrobutylphenol were treated by the EPA trailer, which was generally successful in mitigating environmental effects by filtering and carbon-adsorption. 90% removal was achieved for 21 of 23 compounds.

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

EXPERIMENTS ON THE COMBUSTION OF POLYCHLORINATED BIPHENYLS (PCB) IN 1 M-LONG TUBE FURNACE INDICATED THAT PCB CONTAINING APPROX 40% CL IS DESTROYED WITHIN 3-4 MIN AT 900-1000 °C USING 100% EXCESS AIR. TEMPERATURES GREATER THAN 1000 °C ARE REQUIRED TO DESTROY PCB CONTAINING APPROX 60% CL & DISTILLATION RESIDUES ARISING FROM PCB MFR. DOMESTIC WASTE INCINERATORS OPERATING AT 800-900 °C ARE UNLIKELY TO PROVE SUITABLE FOR INCINERATING WASTE CONTAINING TRACE AMT OF PCB. PYROLYSIS EXPERIMENTS AT 900 °C WITH NOMINAL RESIDENCE TIME OF 3.5 SEC GAVE 40-60% RECOVERY OF CL AS HCL FROM PCB.

POLYCHLORINATED BIPHENYLS CAN BE DESTROYED BY INCINERATION IF THE TRANSIT TIME IS LONG ENOUGH. DURING INCINERATION HEXACHLOROBENZENE IS FORMED; ITS RATE OF FORMATION INCR AT HIGH TEMP. IN ORDER FOR THE HEXACHLOROBENZENE TO BE DESTROYED, A TEMP OF 950 °C IS NEEDED. THIS RESULTS IN THE FORMATION OF A RESIDUE LESS THAN 100 MG OF HEXACHLOROBENZENE/KG. AT 800 °C & A TRANSIT TIME OF 2 SEC, A RESIDUE OF ABOUT 1200 MG/KG REMAINS.

Investigations were conducted of new and emerging technologies for the disposal of hazardous wastes, ... including molten salt combustion, fluidized bed incineration, high energy electron treatment of trace organic compounds in aqueous solution, the catalyzed wet oxidation of toxic chemicals, dehalogenation of compounds by treatment with ultraviolet (UV) light and hydrogen, UV/chlorinolysis of organics in aqueous solution, the catalytic hydrogenation-dechlorination of polychlorinated biphenyls (PCBs), and ultraviolet-ozone destruction. Theory, specific wastes treated, and economics are discussed. The major technologies investigated in detail were molten salt combustion, fluidized bed incineration, and ultraviolet/ozone destruction. Among wastes treated by emerging technologies are PCBs, various dioxins, pesticides and herbicides, chemical warfare agents, explosives and propellants, nitrobenzene, and hydrazine plus its derivatives.

SRP: The scientific literature for the use of contact lenses in industry is conflicting. The benefit or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.

/In a confined space: The worker/ should wear appropriate protective equipment and be connected by a lifeline harness to an outside worker.

Employees should wash their hands before eating, drinking and smoking ... and refrain from such activities in the polluted rooms. ...

... Workers should be provided with suitable protective clothing: long-sleeved overalls, boots, overshoes, and bib-type aprons that cover the boot tops, /and/ gloves. ... Safety glasses with side shields ... for eye protection. Respirators should be used in areas with PCB vapors and during installation and repair of containers and emergency activities. ...

There are no specific treatments for PCB poisoning, since it is not usually recognized until after substantial chronic exposure. Only preventing further exposure and treating the observed symptoms can be done. Acute inhalation can be treated by administering oxygen. (L4)

PRETREATMENT OF RATS WITH 3,4,3'4'-TETRACHLOROBIPHENYL (TCB) OR 2,4,5,2'4'5'-HEXACHLOROBIPHENYL PROTECTED RATS AGAINST BENZENE-INDUCED LYMPHOCYTOPENIA FOR AS LONG AS 7 DAYS, BUT NOT AFTER 10 DAYS OF REPEATED DOSING.

The induction of cytochrome p450 b,e-type antigen and mRNA by phenobarbital, 4,4'-dichlorobiphenyl and 2,4,5,2',4',5'-hexachlorobiphenyl in male Wistar rat liver was studied. Treatment of rats with phenobarbital or 2,4,5,2',4',5'-hexachlorobiphenyl results in a pronounced increase of cytochrome p450 b,e-type antigen and mRNA levels. 2,4,5,2',4',5'-Hexachlorobiphenyl appears to induce primarily a cytochrome p450 b-type sequence.

... A comparison of the time course of monooxygenase enzyme induction and receptor protein elevation by phenobarbital and 2,2',4,4',5,5'-hexachlorobiphenyl showed significant differences in their activities. Five days after administration of the hexachlorobiphenyl, receptor levels were significantly elevated; these increased levels persisted for 14 days. No correlation existed between increased levels of hepatic receptor protein and induction of the cytochrome-p450 dependent monooxygenases, aldrin epoxidase, or dimethylaminoantipyrine-N-demethylase.

Fecal excretion of 2,4,5,2',4',5'-hexachlorobiphenyl was followed for 19 weeks in rats fed a control diet, or a squalane-supplemented diet, for up to 17 weeks. In 3 days after a single oral dose of 8 mg/kg of 2,4,5,2',4',5'-hexachlorobiphenyl, 20% dose was excreted in feces as unchanged 2,4,5,2',4',5'-hexachlorobiphenyl, which probably represents that not absorbed. From day 4 to 133 only an additional 2-4% dose was excreted in feces by control animals. Addition of 8% squalene to the diet 2, 6 and 15 weeks after dosing resulted in a five-fold increase of daily 2,4,5,2',4',5'-hexachlorobiphenyl excretion in feces independent of the time of beginning the treatment. Total excretion of 2,4,5,2',4',5'-hexachlorobiphenyl in feces from day 4 to 133 was 3.6, 6-7 and 9.3% dose after 4, 13 and 17 weeks of squalane treatment, respectively. No adverse effects of long-term squalane treatment on body-weight gain, feed efficiency and organ weights were observed. Plasma cholesterol and triglycerides were significantly lowered. Independent of the duration of treatment, the livers of rats fed the squalene-supplemented diet contained 40-50 ug/g squalene. Within the limits of detection no squalane could be found in lung, kidneys, abdominal fat, spleen, and blood. ...

The most common health effects of PCBs are skin conditions such as chloracne and rashes. Chronic PCB exposure has also been shown to cause liver, stomach and kidney, damage, jaundice, edema, anemia, changes in the immune system, behavioral alterations, and impaired reproduction. (L4)

When uniformly (14)C-labeled ... 2,2',4,4',5,5'-hexachlorobiphenyl was incubated for 98 days in soil ... 0.1% (14)CO2 was evolved in a closed system. Biphenyl and the monochlorobiphenyls were moderately degraded whereas the polychlorinated cmpd were virtually inert.

The mechanism of action varies with the specific PCB. Dioxin-like PCBs bind to the aryl hydrocarbon receptor, which disrupts cell function by altering the transcription of genes, mainly be inducing the expression of hepatic Phase I and Phase II enzymes, especially of the cytochrome P450 family. Most of the toxic effects of PCBs are believed to be results of Ah receptor binding. Other PBCs are believed to interfere with calcium channels and/or change brain dopamine levels. PCBs can also cause endocrine disurption by altering the production of thyroid hormones and binding to estrogen receptors, which can stimulate the growth of certain cancer cells and produce other estrogenic effects, such as reproductive dysfunction. They will bioaccumulate by binding to receptor proteins such as uteroglobin. (A3, A4, A30, A66)

A PCB CONCN OF 3608 PPM WAS FOUND IN FAT FROM SNAPPING TURTLE COLLECTED FROM UPPER HUDSON RIVER (HIGH POLLUTION LEVEL). THIS TURTLE REFLECTS THE HIGH PCB LEVELS FOUND IN THE REGION AS COMPARED TO THE 633 PPM PCB LEVEL FOUND IN FAT FROM SNAPPING TURTLE FROM LAKE ONTARIO (LOW POLLUTION LEVEL). 2,2'4,4'5,5'-HEXACHLOROBIPHENYL WAS THE MOST COMMON PCB FOUND IN BOTH TURTLES.

The following link will take the user to the National Toxicology Program (NTP) Test Agent Search Results page, which tabulates all of the "Standard Toxicology & Carcinogenesis Studies", "Developmental Studies", and "Genetic Toxicity Studies" performed with this chemical. Clicking on the "Testing Status" link will take the user to the status (i.e., in review, in progress, in preparation, on test, completed, etc.) and results of all the studies that the NTP has done on this chemical. [http://ntp-apps.niehs.nih.gov/ntp_tox/index.cfm?fuseaction=ntpsearch.searchresults&searchterm=35065-27-1]

Found in various Aroclor products; [HSDB]

PCB's not commercially produced in the US since 1977; [HSDB]

PCBs were used as coolants and lubricants in transformers, capacitors, and other electrical devices (such as fluorescent lights and refridgerators) produced before 1977. PCBs may contaminate the air and water near hazardous waste sites. In addition, PCBs bioaccumulate in the environment and may be found in fish, meat, and dairy products. (L4)

DOMESTIC /USA/ PRODUCTION OF POLYCHLORINATED BIPHENYLS WAS STOPPED IN OCTOBER 1977. /POLYCHLORINATED BIPHENYLS/

Aroclor 1260 contained nearly 80 different polychlorinated biphenyl congers.