• Korean Journal of Hazardous Materials
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• v.2 no.1
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• pp.18-26
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• 2014

We analyzed the demand of competent authorities requiring adequate technical information for initial investigation of chemical accidents. Reflecting technical reports on chemical accident response by environmental agencies in the U.S. and Canada, we presented information on environmental diffusion and toxic effects available for the first chemical accident response. Hydrogen fluoride may have the risk potential to corrode metals and cause serious burns and eye damages. In case of inhalation or intake, it could have severe health effects. The substance itself is inflammable, but once heated, it decomposes producing corrosive and toxic fume. In case of contact with water, it can produce toxic, corrosive, flammable or explosive gases and its solution, a strong acid, may react fiercely with a base. In case of hydrogen fluoride leak, the preventive measures are to decrease steam generation in exposed sites, prevent the transfer of vapor cloud and promptly respond using inflammable substances including calcium carbonate, sodium bicarbonate, ground limestone, dried soil, dry sand, vermiculite, fly ash and powder cement. The method for fire fighting is to suppress fire with manless hose stanchions or monitor nozzles by wearing the whole body protective clothing equipped with over-pressure self-contained breathing apparatus from distance. In case of transport accident accompanied with fire, evacuation distance is 1,600m radius. In cae of fire, fire suppression needs to be performed using dry chemicals, CO₂, water spray, water fog, and alcohol-resistance foam, etc. The major symptoms by exposure route are dyspnoea, bronchitis, chemical pneumonia and pulmonary edema for respiration, skin laceration, dermatitis, burn, frostbite and erythema for eyes, and nausea, diarrhea, stomachache, and tissue destruction for digestive organs. In atmosphere, its persistency is low, and its bioaccumulation in aquatic organism is also low.

• Journal of Oral Medicine and Pain
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• v.38 no.2
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• pp.109-114
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• 2013

Chemical burn on the oral mucosa is caused by contact with various chemical products and manifests with localized mucositis, keratotic white lesions, bleeding, and painful tissue surface due to the coagulation of the tissue. Policresulen ($Albothyl^{(R)}$) is a topical antiseptic, commonly used over-the-counter drug for vaginitis, thrush and stomatitis. This drug is highly acidic with pH 0.6, and can act as a strong corrosive agent to oral mucosa. When inadvertently used in oral cavity, it may cause chemical burns of oral mucosa, resulting necrosis and bleeding surface resembling to erythema multifome. A 56 years old female patient presented with the chief complaints of painful ulcerations on the tongue, the upper and lower lips. On intraoral examination, an erythromatous, erosive or ulcerative surface covered with inflammatory exudates or bleeding crust is observed on the anterior half of the tongue and the upper and lower lips. She has occasionally applied the policresulen solution topically on the tongue to relieve pain from recurrent focal glossitis for about 10 years. In this time she applied it broadly and repeatedly to the tongue, the upper and lower lips for the purpose of pain relief by herself without instruction by physician or dentist. After cessation of policresulen application, the oral mucosa was rapidly recovered with use of topical steroids. In 2 weeks the lesions subsided completely. In summary, inadvertent use of $Albothyl^{(R)}$ on oral mucosa may result in chemical burn, causing mucosal erosion, ulceration and inflammation. It can be recovered by topical use of corticosteroid for 2 weeks after cessation of using $Albothyl^{(R)}$.

• Journal of Chest Surgery
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• v.6 no.2
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• pp.225-230
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• 1973

Five cases of esophageal cancer developed at the site of esophageal lye stricture were reported. Duration of lye stricture was between 13 and 40years, and all 5 cases had taken normal diet without appreciable troubles after recovery from the acute stage of burn till the suspected onset of esophageal malignaney. Outstanding symptoms of this grave condition were rather acute progressive dysphagia and frequent episodes of esophageal foreign bodies, Diagnosis could be confirmed easily by endoscopic biopsy in suspected eases, and all were epidermoid carcinoma histopathologically. Curative resection of this condition was made in neither of the cases, and their prognoses were more grave than other esophageal malignancies in our experience. The development of esophageal carcinoma at the site of corrosive esophagitis with resulting benign stricture has now been suspected as a cause and effect relationship between these two conditions, and Kiviranta: stated that the incidence of esophageal cancer in patients with lye stricture of longer duration is a thousand times higher than normal population. During last one decade the authors experienced 5 cases of esophageal carcinoma developed at the site of lye stricture of the esophagus among about 350 cases of lye burned esophagus at the Department of Thoracic & Cardiovascular Surgery, the National Medical Center in Seoul, Korea. In Korea they still use lye as a detergent in rural area, and there are still many persons ingesting lye for suicidal attempt or on accident. Lye stricture of the esophagus is, therefore, the most common esophageal disease needing surgical procedures, and the authors believe that there will be much more eases of lye stricture complicated by esophageal eareinoma repoted in near future in this Country.

• Air Cleaning Technology
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• v.17 no.4 s.67
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• pp.39-57
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• 2004

첨단산업으로 불리는 반도체, LCD, PDP, 유기EL(OLED) 등의 생산 공정은 고도의 청정상태를 요구하며, 때문에 이들의 생산공정 중 대부분이 클린룸 내에서 이루어진다. 클린룸 내에서의 주요공정은 크게 박막형성(Layering), 노광(Photo Lithography), 식각(Etching) 등 3가지 공정으로 나눌 수 있으며, 반도체 제조공정의 경우 특별히 도핑(Doping) 공정이 추가된다. 오염물질을 함유하는 클린룸 배기는 일반적으로 산, 알칼리, Toxic(PFCs, Flammable), VOC 등으로 분류하며, 각각의 배기는 각 배기특성에 맞는 오염제어 장치를 통해, 정화된 후, 대기로 방출된다. 산, 알칼리 배기는 일반적으로 최종 단계에서 중앙집중식 습식스크러버에 의해 흡수, 중화 처리되며, VOC의 경우 농축기(Concentrator) & 축열식 열 산화장치(RTO) 설비에 의해 연소 처리된다. 하지만 CVD공정으로부터의 배기가 주를 이루는 Toxic배기의 경우, 다량의 PFCs(과불소화합물) 가스를 함유하고 있는 이유로, 대부분 클린룸 내부에 P.O.U(Point of use) 처리장치가 설치되며, P.O.U에 의해 1차 처리된 후 최종적으로 중앙집중식 습식스크러버를 거쳐 대기로 방출된다. 알칼리배기의 주성분으로는 암모니아($NH_3$), HMDS (Hexa Methyl DiSilazane), TMAH (Tetra Methyl Ammonium Hydroxide), LGL, CD 등이며 흡수액에 황산(Sulfuric Acid)용액을 공급, 중화처리하고 있다. 탄소성분을 먹이로 하는 미생물의 번식에 의한 막힘 문제를 제외하고는 큰 문제가 없다. 하지만 Toxic배기 및 산배기의 경우 처리효율이, 가스흡수 이론에 의한 계산결과와 비교할 때, 매우 저조하게 나타나는 효율부족 현상을 겪고 있으며, 이는 잔여 PFCs 가스성분 및 반응에어로졸, 응축에어로졸 등의 영향으로 추정하고 있다. 최근 Toxic 배기의 경우, P.O.U 설비를 Burn & Wet type으로 변경하여, 배기 중 PFCs 및 반응에 에어로졸($SiO_2$)의 농도를 원천적으로 감소시키는 노력이 진행 중이다. 산배기의 경우, 산결로 현상에 의한, 응축에어로졸이 문제가 되고 있으나 내식열교환기(Anti-Corrosive Heat Exchanger), 하전액적스크러버 시스템(Charged Droplets Scrubber System), Wet ESP(Wet Electrostatic Procipitator) 등의 도입을 통해 문제해결을 위한 노력을 경주하고 있다.