• 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.

• 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.

• 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.

• 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.

• Korean Journal of Microbiology
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• v.11 no.4
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• pp.181-188
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• 1973

For the bulk sterilization, there are two traditional methods of autoclaving and exposure to ethylene oxide. However, autoclaving involves high temperatures and pressures and ethylene oxide is chemically highly reactive, so these methods are radiation, we have carried out sterility and safety tests on some medical products irradiated at varying radiation levels. The results obtained were as follows ; 1) The minimum dose of radiation for the sterilization of medical products was 2.5 Mrad. 2) The radiosterilization dose varied depending on the initial population of microorganisms. 3) In transfusion sets, a level of radiation of 2.5Mrad at room temperature produced no pyrogen and they remained bacteriologically sterile.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.6
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• pp.635-639
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• 2008

Objectives : the effect of different sterilization methods on the surface morphology of PPDO-hybrid-PLGA nanofiber scaffold and attachments of PC12 cell were investigated. Methods : Poly (p-dioxone)-hybrid-Poly (lactide-glycolide) (PPDO-hybrid-PLGA) nanofiber scaffold, fabricated in a tube form with 1.5 mm internal diameter, 0.2 mm thickness and 5 mm length, was prepared using electrospinning method. To study the surface morphology using SEM, The study group and control group in respective were; Control:Non-sterilized scaffold, Group I:scaffold sterilized with 70% Alcohol, Group II: scaffold sterilized with Ethylene Oxide at $65^{\circ}C$, and Group III: scaffold sterilized with Ethylene Oxide at $37^{\circ}C$. To investigate viability of the PC12 cell on the scaffold, The study group and control group in respective were; Control: sterilized with 70% Alcohol, Group I: sterilized with Ethylene Oxide at $65^{\circ}C$, and Group II: sterilized with Ethylene Oxide at $37^{\circ}C$. Results : 1. The surface morphology was slightly changed in Group I, II and Group III, compared with control. 2. The attachment of PC12 cells in Group I, II was not higher than in control Discussion : The attachment of PC12 cell is not influenced by different sterilization methods.

• Journal of Food Hygiene and Safety
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• v.1 no.1
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• pp.39-46
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• 1986

Comparison of ethylene oxide(E.O) fumigation and gamma irradiation on the sterilization, microbiological, physicochemcial and sensory quality of dried fishery products (shucked shellfish and mussel powder) were investigated. The viable cell count of mesophilic total bacterial was reduced by over 2 to 3 log cycles with irradiation of 3 to 5 kGy, and those samples were completely sterilized by irradiation dose of 7 to 10 kGy. In view of reduction of microorganisms, D10 value of each samples were ranged from 1. 36-1. 46 kGy. fungi, mesophilic spores, acid tolerant bacteria and coliforms were sterilized at 5 to 7 kGy irradiation but E.O. fumigation proved insulfficient to eliminate the mesophilic total bacteria and fungi. In the physicochemical and sensory quality of samples, such as the amino acid, TBA value, TMA-N, color difference and overall acceptability irradiated sample with optimum dose was similar to those of the nonirradiated sample, while E.O. fumigated sample was remarkably deteriorated in the physicochemical and sensory quality of samples.

• Applied Biological Chemistry
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• v.30 no.2
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• pp.126-132
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• 1987

The usual sterilization methods such as fumigation and autoclaving of laboratory rodent diet was compared with a new irradiation treatment in the point of sterilization effect and physico-chemical quality. Under the treatments of $10{\sim}20\;kGy$ ${\gamma}-irradiation$ and autoclaving at $121^{\circ}C$ for 20 min, total microorganisms were eliminated but ethylene oxide fumigation was insufficient to destory them. Total amino acid content was reduced about 5% in 20 kGy radiation treatment compared with control, while in the ethylene oxide fumigation and the autoclaving, the reducing rate was markedly great as 15% and 20%, respectively. Total sugar and mineral contents were not significantly different among treatment among treatment groups. TBA values were increased in all treatments. The pH of irradiated group war stable in comparison with that of ethylene oxide. In the treatments of ethylene oxide and especially autoclaving, overall appearance was decreased to a great extent as a result of decreasing lightness and increasing redness.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.5 no.1
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• pp.68-86
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• 1995

This study was conducted at five Ethylene Oxide(EO) sterilizing processes in hospitals located in Seoul from August 8 to August 30, 1994. The main purposes of this study were to assess the TWA(Time Weighted Average) and short term exposures to EO and to evaluate factors affecting EO concentrations in sterilizing room. Results are summarized as follows. 1. The TWA concentrations of the sterilizing operators ranged from <0.005ppm to 3.04ppm and those of two sterilizing rooms out of five exceeded 1ppm, the Korean and ACGIH standards. 2. When the door of the sterilizer is opened at the end of the sterilization cycle, the short term concentrations of operators ranged from <0.005ppm to 11.4ppm, and those of three sterilizing room out of five exceeded 5ppm, the ACGIH short term exposure limit(STEL). The short term concentrations of area samples ranged from 0.24ppm to 49.2ppm and those of four sterilizing room out of five exceeded 5ppm. 3. Factors affecting EO exposure level were aeration type, the location of storage site for sterilized item, amount of gas, use period of sterilizer(p<0.005). 4. Following recommendations are suggested to minimize exposure to EO. The use of EO gas should be reduced by using another available sterilization methods, and the sterilizers and gas tank storage site should be isolated from, other work areas. Combination of local and general ventilation system should be installed. Metal carts or baskets for sterilization load should be used, and work environment and medical monitoring should be performed regularly.

• 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.