• 한국환경농학회지
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• 제17권4호
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• pp.368-370
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• 1998

In order to determine the optimal radiation dose for the sterilization of biowastes, the bioburden, frequencies and radiosensitivities of bacteria, mold and fungi in rice straw, chaff, corn stover and sawdust was observed before and after ${\gamma}-ray$ irradiation. Radiation sterilization dose of rice straw, chaff, com stover and sawdust was calculated as 17.7, 17.6, 15.6 and 20.0kGy, respectively, from the mutual compensation of screening dose and derived dose on the basis of $10^{-3}$ SAL. This method could be acceptable for the sterilization of various biowastes including food, pharmaceuticals, etc.

• 미생물학회지
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• 제5권1호
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• pp.7-14
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• 1967

The synergistic actions of certain antimetabolic agents for Saccharomyces cerevisiae and Lactobacillus plantarum on radiation sterilization have been studied. The used chemical agents are sorbic acid, vitamin-$K_3$, dehydroacetic acid, p-oxybutyl benzoate and nitrofurazone, those are the permitted as food preservatives. Experimental results are as following, 1) Survival fraction of yeast which was gamma-irradiated and influenced by sorbic acid or vitamin $K_3$ is much reduced than that of only irradiated respectively. 2) It seems like that the used chemicals acts synergistically on radiation sterilization. Sodium-dehydroacetate and p-oxybutyl benzoate are proved to be also synergistic but weakly. 3) Survival fraction of Lact. plantarum which was gamma-irradiated and influenced by sorbic acid, dehydroacetic acid or nitrofurazone respectively much reduced than that of only irradiated group, it can be estimated as synergistic action of chemical affected on radiation sterilization. 4) It was found that nutrient componets can affect radiation sterilization of microorganisms protectively.

• 한국환경보건학회지
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• 제8권1호
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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.

• 방사선산업학회지
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• 제8권2호
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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.

• 미생물학회지
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• 제11권4호
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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.

• 식품산업과 영양
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• 제11권3호
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• pp.21-29
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• 2006

• Journal of Electrical Engineering and Technology
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• 제6권2호
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• pp.275-279
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• 2011

Sterilization of Escherichia coli (E. coli) is examined using a unique pulsed ultra-violet (UV) elliptical reactor based on Nd:YAG laser resonator, UV radiation from a pulsed xenon flashlamp. The light from the discharge has a broadband emission spectrum extending from the UV to the infrared region with a rich UV contained. Sterilization method by using the UV light is fast, environment-friendly and it does not cause secondary pollution. A Nd:YAG laser resonator having elliptical shape has advantage of concentrating the radiation of the UV light at two foci as the quart sleeve filled with E. coli. The primary objective of this research is to determine the important parameters such as pulse per second (pps), the applied voltage for sterilizing E. coli by using an UV elliptical reactor. From the experiment result, the sterilization effect of UV elliptical reactor is better than that of UV cylindrical reactor, and it can be 99.9% of sterilization at 800V regardless of the pps within 10 minutes.

• 한국방사선학회논문지
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• 제14권5호
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• pp.695-703
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• 2020

의료기술 발전으로 인해 의료기기 사용이 증가하는 추세이다. 의료기기 중 이식 및 치료를 위해 인체 내에 사용되는 경우가 많다. 그러므로 의료기관에서는 감염 예방을 위해 의료기기 형태와 재질에 따른 멸균법들이 다양하게 적용되고 있다. 뼈 이식에서 수산화인화석 재료가 가장 많이 보급되어 있다. 소형 의료기기에 알맞은 비전리방사선 중 고출력에너지를 가진 Q-switch Nd:YAG 레이저를 이용한 멸균법을 제시하고자 한다. 대장균과 충치균을 수산화인화석 디스크에 오염시켜, 출력1.5 W, 파장은 각각 자외선(266, 355 nm), 가시광선(532 nm), 적외선(1,064 nm), 1과 10 펄스를 각각 조사하였다, 본 연구에서 자외선 파장인 1.5 W, 266 nm, 10 pulse에서 멸균력을 가장 이상적으로 보여주었다. 다른 파장대인 적외선, 가시광선은 소극적 멸균력을 보였으며, 자외선 A와 자외선 C는 펄스에 따라 멸균 차이를 보였다. 레이저 멸균에서 파장 및 펄스에 따라 멸균 차이를 알 수 있었다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제27권6호
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• pp.523-527
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• 2005

Allograft donations are commonly found to be contaminated. The most of tissue banks has promoted the use of ionizing radiation for the sterilization of biological tissues. The potential for transmission of human infectious diseases and contamination of microorganism has created serious concern for the continued clinical use of hard and soft-tissue allografts. Tissue banks have employed 15-25kGy for sterilization of hard and tendon allografts, which, according to the national standards, approaches the level at which the tissue quality is adversely affected for transplantation. The donations of allogeneic tissues to the Korea Tissue Bank over a 2-year period were reviewed, and the incidence and bacteriology of contamination were detailed. Clinical outcomes were determined for donors who had positive cultures at the time of retrieval and during the processing and they were compared with those of post sterilization. After exposure of the frozen block bone to 25kGy and the processed tissues to 15kGy of gamma irradiation, the authors were able to demonstrate complete inactivation of the bacteria. The aim of this study was to obtain the effects of gamma irradiation and the irradiation dose according to the type of tissue, through conventional microbiologic test without on influence of biocompatibility in allografts. The contamination rate after the final irradiation sterilization is 0% in the processed allografts. This may be due to the fact that the gamma radiation and processing steps are effective to control contamination.

• 한국환경보건학회지
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• 제5권1호
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• pp.1-9
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• 1978

Biological safety, physico-chemical and microbiological experiments were carried out in order to study the possibility of radiation sterilization on medical products, such as polyethylene and polystyrene bottles, gauze sponges and surgical silk suture. Results are as follows: 1. Biological test on plastic samples as to acute systemic toxicity, eye irritation, skin irritation, pyrogen, haemolysis showed satisfactory results. But physico-chemically, the oxidizable matter, nonvolatile residues, residue on ignition seemed to be increased slightly in irradiated samples, though the experimental results were within the range of U.S.P. 19, N.F. and K.P. III. 2. After irradiation, both plastic and gauze sponges showed considerable decrease in pH. 3. Most medical products were sterilized by 1.5 Mard. For the sterilization of the suigical silk suture, 4.5 Mrad is required dul to its radiation resistant micro-organisms. 4. Biologically, total dose of 2.5 Mrad was safe enough to sterilize the medical products, and physico-chemically the results are acceptable according to U.S.P. 19 and K.P. III. However, better results may be expected when the quality of material and additives are improved.