• Air Cleaning Technology
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• v.23 no.3
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• pp.34-43
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• 2010

In most productive facility of pharmaceutical companies, the fumigation using formaldehyde gas has been put into operation. Because formaldehyde gas is so bactericidal as to sterilize bacterial spore which can not be sterilized with usual disinfectants, it has been used for fumigation in many facilities such as facility of experimental animals, research institute and productive facility of pharmaceutical companies which are required to be high level of biological clean. However, the use of formaldehyde is recently under the strict management because of its causing of sick house and carcinogenesis. We introduce the conditions of sterilization using formaldehyde gas, the examples of sterilization using formaldehyde gas in a pharmaceutical manufacture and the problems of use of formaldehyde against environments and health. Further, we describe the characteristics and future subjects of the sterilization method using gasified oxidants such as hydrogen peroxide, peracetic acid and chlorine oxide.

• The Korean Journal of Food And Nutrition
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• v.31 no.2
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• pp.308-312
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• 2018

Even though chlorine dioxide ($ClO_2$) is utilized in a pre-treatment due to its effective sterilizing activity for microorganisms and its safety for food, it has a limitation in maintaining freshness of the food product. In this study, a low-concentration $ClO_2$ gas was produced in a packaging form of air-permeable gel pack so that it could be released continuously over several days. The amount of $ClO_2$ gas emission and microbial inactivation effect against foodborne pathogens were measured during the release of $ClO_2$ gas. As a result of measuring the change of color in order to confirm whether the chlorine dioxide gas was eluted in the form of a sustained release, the yellowness was significantly higher at higher gel pack concentration and higher value during storage periods. The slow-released $ClO_2$ gel-pack showed clear inactivation effect against Escherichia coli and Staphylococcus aureus with 99.9% inactivation efficiency. As a result of measuring the sterilization effect of Listeria monocytogenes by the concentration of chlorine dioxide gas, the sterilization effect was increased as the concentration was increased. Therefore, the slow-released $ClO_2$ gel-pack is feasible to apply for industry usages.

• International Journal of Industrial Entomology and Biomaterials
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• v.42 no.2
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• pp.46-50
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• 2021

When 4-hexylresorcinol (4HR) incorporated silk mat is used for clinical application, sterilization process is essential. In this study, 4HR incorporated silk mat was sterilized with ethylene oxide (EO) gas or autoclave, and then antibacterial property was evaluated. For the examination of micro-structure after the sterilization, scanning electron microscopic (SEM) exam and Fourier Transform Infrared (FT-IR) spectroscopy were also done. There was no gross difference after sterilization in SEM exam and FT-IR spectra. Antibacterial property of 4HR was also maintained after the sterilization. In conclusion, EO gas or autoclave did not damage the antibacterial property of 4HR in the silk mat.

• Journal of Environmental Health Sciences
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• v.8 no.1
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• pp.81-97
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• 1982

Ethylene oxide gas has been used as a cold sterilant for heat-sensitive medical equipments and as a fumigant for food for more than 30 years, and it is used more widely than radiation although radiation sterilization has made significant inroads in recent years. But according to recent studies of toxicities such as mutagenicity, haemolytic effect and possible carcinogenicity of Ethylene oxide (ETO) and its two main reaction products, Ethylene chlorohydrin (ETCH) and Ethylene glycol (ETG), Environmental Protection Agency in U.S.A. has suggested some regulations on residual gas in drug products and medical devices for human use. The mutagenic activity of ETO compared with that of X-ray has an equivalency of 1 ppm/hr for ETO as compared to 20 mrad for X-ray, and one could suggest the present maximum allowable concentration for ETO (50 ppm) should be 400 times lower than the radiation standard (2.5 mrad/hr). Although radiation sterilization has advantages of simplicity of operation and complete reliability, changes of physico-chemical properties with possible formation of toxic substances may occur. It is therefore necessary to make some regulations of our own for residual toxicities orginated from each sterilization method.

• The Korean Journal of Food And Nutrition
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• v.36 no.4
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• pp.334-339
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• 2023

To suppress mold generation of yujacheong, Penicillium chrysogenum LB31 was cultured, and spores were harvested and put into yujacheong. Antioxidant activity, useful ingredients, mold size and incidence were investigated while storing yujacheong for 30 days, after sterilization with different methods (nontreatment, ozone gas emission, heating after ozone gas emission and heating). The results showed that the content of narirutin, naringin, hesperidin, or neohesperidin, which are functional components of yuzu, increased as the storage period increased in all the treatment units. In addition, mold generation was not observed until the 15th day in the heat treatment group after ozone gas emission. As the treatment group emitted ozone gas. molds of 34.8 and 112 mm2 in size were observed on the 30th day. These results suggested that ozone sterilization can prevent microbial contamination, further extending the shelf life of yuzacheong and maintaining a fresh state.

• Applied Chemistry for Engineering
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• v.22 no.3
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• pp.261-265
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• 2011

The sterilization effects of atmospheric pressure plasma with the mixture of argon and oxygen were analyzed. The plasma reactor with the shape of dielectric barrier discharge produced the uniform distribution of glow discharge and generated ozone gas effectively according to the various process parameters. The sterilization for E. coli was affected by power, oxygen ratio in the mixture gas, treatment time and distance between reactor and sample. The concentration of ozone was a major source for the sterilization of E. coli, which was enhanced by the increase of power and oxygen ratio. In this study, the effect of atmospheric pressure plasma treatment for the sterilization was confirmed and its result can deliver the atmospheric pressure plasma treatment as the novel sterilization method instead of conventional methods.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.13 no.4
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• pp.405-411
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• 1991

To determine the sterility of the prepared allogeneic bone of the human, culture of the allografts prior to implantation was performed on fresh-frozen and freeze-dried bone. Before the use of allografts to the patients, it must be confirmed about the sterility, cellular cytotoxicity, immune reaction, and osteoinductive potential as a biomaterials. Oral and maxillofacial surgeons demand for allograft bone will be increased in the future. Wonkwang Bone Bank attempted to meet this demand, has performed series of experimental study on the allograft bone of the Koreans to evaluate the physical and chemical suitability of the bone since the surgeons applications will have broadened from benign cystic lesions to fracture malunions and non-unions, large segmental defects, and whole-bone allorgrafts after tumor surgery. The results obtained were as follows: 1. Freeze-drying(FD) only shoed some bactericidal effects of the normal and osteo bone but in cases of performing EO gas sterilization, the FD effects was not clear. 2. The fact that FD has little effect than the EO gas sterilization on normal bone postulated that the presence of microbiota may be due to an operation and bone processing procedure. 3. FD and EO gas sterilization had a remarkable effect on the osteo bone. 4. The sterilization effect were EO gas, Freeze-drying, Fresh-Frozen with descending order. But all sterilization method were not complete to preserve and implant allograft bone. We are now performing further continuous study on the radiation and chemical sterilization procedure to make safe and complete allograft bone.

• Journal of Radiation Industry
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• v.8 no.2
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• pp.133-140
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• 2014

The sterilization of health care products is widely used to choose conventional Ethylene Oxide gas sterilization in South Korea. But the method has brought serious issues because of the toxic residual gas and global warming of $CO_2$ evacuation after the sterilization process. This study is carried out to confirm the application possibility of gamma sterilization instead of Ethylene Oxide in sanitary aid products. Four kinds of products (gauze, menstrual pad, bandage, menstrual tampon) were treated with gamma irradiation of 15 kGy, then analyzed the achievement of the sterility assurance level (SAL) $10^{-6}$ through BI test. The cytotoxicity of accelerated samples of 6 months elapse evaluated by means of colony forming rate at various concentration of the extracts. pH and UV measurements at extract concentrations were tested according to the MFDS (Ministry of food & drug safety) guideline to verify a stability & safety of product sterilized. The results revealed that the extracts did not show any significant changes in cytoxicity assay as well as pH and UV values by gamma sterilization. All extract concentration was observed high cell viability, pH and UV values were calculated within the acceptable range prescribed by the guideline. It indicates that gamma sterilization could effectively substitute for conventional sterilization such as Ethylene Oxide sterilization in the sanitary aid products.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.21 no.2
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• pp.141-150
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• 2014

Purpose: This was a study on the expiration date of Ethylene Oxide (EO) gas sterilization and effects of the environmental factors of temperature, humidity and type of cabinet in sterile goods storage area on the expiration date. Methods: Sterile goods storage areas from 13 departments in one hospital were selected and 455 EO gas sterilization samples were prepared and kept in those areas over the 14 months of the study. Each sample was tested with a microbiological culture in the laboratory every week. If the result was positive, the sample was regarded as contaminated. The researcher visited once a month to check the temperature, humidity and type of cabinet. Results: With the exception of 1 sample which was positive at 56th week. 454 samples were confirmed as negative. The environment of the samples storage area was measured monthly. The annual average temperature was $24.2{\pm}1.6^{\circ}C$, and the mean relative humidity $34.7{\pm}15.2%$. The types of cabinet were 7 open and 6 closed. Conclusion: The results of the microbiological culture at 13 months showed that none of the samples were contaminated. Therefore the hospital's existing Expiration Date can be extended from 6 months to 13~14 months.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.19 no.3
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• pp.287-299
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• 1997

Procurement, cutting, cleansing, freezing, freeze-drying, and demineralization of the allogeneic bone must be made under the germ-free stable condition without bacterial and/or viral contamination. Even thought the bone is procured under the germ free condition, we must have confidence on disinfection of all the solutions that come in contact with tissue during the whole procedure. Lots of antibacterial agents have been introduced for chemical sterilization. Recently ethylene oxide gas sterilization or radiation sterilization is frequently selected as a secendary sterilization procedure. The biological and biochemical response of the graft material differs with the type and concentration of the sterilizing agents, and various toxic reactions have been reported due to the graft material itself and the substance released by the chemicals. The authors conducted the Millipore filter test to observe the toxic effect on L929 fibroblasts according to the effect on activity of succinate dehydrogenase, during the secondary sterilization of the demineralized allogeneic bone powder with irradiation or ethylene oxide gas. The result were as follows : 1. Around the copper disk, positive control group, 10mm diameter discoloration was observed. 2. As same as the negative control group, the disk showed no discoloration. 3. The demineralized allogeneic bone which was sterilized with ethylene oxide gas or irradiation showed no cytotoxicity. 4. From this results, it is suggested that treatment with ethylene oxide gas or irradiation should be effective to sterilize the deminineralized allogeneic bone.