• Particle and aerosol research
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• v.18 no.2
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• pp.37-50
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• 2022

Due to the syndrome coronavirus 2 (SARS-CoV-2) pandemic, the subway passenger cabin should be continuously sterilized. However, a disinfectant such as chlorine is toxic and can lead to different issues to human health. In this paper, we introduced a novel disinfectant based on natural product (Dendropanax morbifera extract). Via ultra-high performance liquid chromatography - mass spectrometer (UHPLC-MS), different compounds from Dendropanax morbifera extract showed antivirus potentials. Antimicrobial experiments confirmed that the air-disinfectant containing Dendropanax morbifera can eliminate harmful microorganisms including Gram (-), Gram (+), and yeast within 5 mins. The as-prepared air-disinfectant also showed high antivirus activity against H1N1, HRV, and EV71. Deodorization test also indicates that the as-prepared air-disinfectant can lower the harmful gas such as ammonia and trimethylamine in the atmosphere. To evaluate the potential of air-disinfectant containing Dendropanax morbifera in practical applications, different safety tests including acute oral toxicity, acute skin irritation, and eye irritation were conducted. Results showed that the as-prepared disinfectant did not negatively affect tested animals during these safety investigations.

• Journal of Environmental Health Sciences
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• v.31 no.5 s.86
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• pp.411-414
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• 2005

Clean Natural is a new disinfectant of which main components are propolis and wood vinegar from Quercus mongolica. The mutagenicity of Clean Natural was studied by a micronucleus test in male ICR mice. The maximally tolerated dose (MTI) of Clean Natural was determined to >2.0 g/kg body weight. Therefore, the doses adopted for the micronucleus test was 2.0 g/kg as a high dose, 1.0 g/kg as a medium and 0.5 g/kg as a low of dose, respectively. Each of group was consisted of three doses of Clean Natural, positive control 2 mg/kg of mitomycin C and negative control 20 ml/kg of saline. A slide preparation was made at 24 hours following administration. No significant induction of micronuclei was observed in any of the three doses of Clean Natural orally administered. No cytotoxicity such as inhibition of hemopoiesis was observed in any group of test agent as the rate of polychromatic erythrocytes to total erythrocytes was over 40%. These results indicate that Clean Natural is not capable of inducing micronuclei in vivo mouse cells and thus has no genotoxicity in micronucleus test.

• Toxicological Research
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• v.21 no.3
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• pp.263-269
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• 2005

This study was performed to investigate repeated-dose toxicities of Clean natural, a new disinfectant, in Sprague-Dawley(SD) rats. In the 4-week repeated oral toxicity study, Clean Natural was orally administered once daily via gavage to male and female rats at dose levels of 0, 500, 1,000 and 2,000 mg/kg body weight for 4-weeks. There were no deaths and clinical signs during the dosing period. In both sexes, there were no statistically significant differences between the administered and control groups in urinalysis indicators and hematological parameters. In serum biochemistry, aspartate aminotransferase(AST) was significantly decreased and sodium content was increased in the 2,000 mg/kg male group, while chlorine was significantly decreased in the 2,000 mg/kg female group. Also, albumin, total cholesterol and total bilirubin were significantly increased in the 2,000 mg/kg male and female group. In histopathological examinations, centrilobular hepatocellular hypertrophy in the liver was observed in the 2,000 mg/kg male and female groups. And pigmentation in the spleen was observed in the 2,000 mg/kg male group. In conclusion, four-week repeated oral dose of Clean Natural to rats did not cause apparent toxicological change at the dose less than 2,000 mg/kg body weight. Thus it is suggested that no-observed adverse-effect level(NOAEL) for Clean Natural in rats was considered to be 1,000 mg/kg/day.

• Journal of Korean Ophthalmic Optics Society
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• v.10 no.1
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• pp.63-69
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• 2005

The effects of R products of B company and natural disinfectant naringin, well-known chemical disinfectant on Corneal endothelium and epithelium of rabbit were observed by scanning electron microscope. The main component of naringin is extract of grapefruit seed, which is one of the flavonoid widely recognized as natural antioxidants and used as preservative agent of food and cosmetics. The chemical disinfectants cytotoxicity in cell cultures were announced by MIT assay and LDH leakage assay. But there has been no study about that chemical disinfectants and natural disinfectants is inserted drops on rabbit's cornea directly. In this test R products B company and natural disinfectants has been dropped on the cornea of rabbits for one weeks and observed cytotoxiciy by light camera after rose bengal staining. Also, we analysed the damage of corneal epithelium and endothelium morphologically after enucleating the cornea by scanning electron microscope.

• Journal of Korean Ophthalmic Optics Society
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• v.8 no.2
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• pp.65-69
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• 2003

The effects of grapefruit seed extract and $H_2O_2$ disinfectants on Pseudomonas aeruginosa were investigated by antimicrobial assay and scanning electron microscopy. Pseudomonas aeruginosa is a Gram negative bacteria and a common causative microorganism of bacterial keratitis. After incubation of soft contact lens in Pseudomonas aeruginosa suspension for 120 minutes containing the disinfectants, the grapefruit seed extract showed antimicrobial activity as good as the chemical disinfectant. The living rates of Pseudomonas aeruginosa in grapefruit seed extract and $H_2O_2$ disinfectants were $1{\times10^3CFU/m{\ell}$ and $0.5{\times}10^3CFU/m{\ell}$, respectively showing no major difference in the killing activity. However, the mechanisms of the antimicrobial activity were quite different as indicated by scanning electron microscopy of the bacterial surface morphology. Considering chemically or other toxins induced keratitis, the natural disinfectant isolated from grapefruit seed extract shows promising results as a soft contact lens disinfectant.

• Journal of fish pathology
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• v.12 no.1
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• pp.42-48
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• 1999

The disinfectant effects of total residual oxidants (TROs) produced by ozonization of natural sea water were investigated against fish pathogenic bacteria isolated from flounder and red seabream. The concentration of 0.1 mg TROs/liter was stable for 20 min in filtered natural seawater, and those of 0.3 and 0.5 mg TROs/liter were also stable for more 1 hr. Disinfectant effects of TRO against Edwardsiella tarda, Vibrio sp., Streptococcus sp. and Staphylococcus sp. were observed with a concentration of 0.1 mg/liter for 180 sec, and the treatment killed more than 99.9% of bacterial cells. With TROs of 0.3 to 0.5 mg/ liter, the viable cells of the bacteria were reduced by more than 99.99% in 60 sec.

• Journal of Environmental Health Sciences
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• v.45 no.4
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• pp.340-357
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• 2019

The purpose of this paper is to help develop a comprehensive understanding of the humidifier disinfectant disaster from diverse perspectives based on a critical review of the relevant academic research papers published so far in the fields of both natural and social science. The authors reviewed pertinent articles in the six academic areas of law, social science, humanities, medicine, toxicology, and environmental health. A proper understanding of the issue of humidifier disinfectant is a challenging task because diverse aspects of it have become related over the more than two decades since such products were first released to the market in 1994. Technical and esoteric issues such as the complex system for relief and compensation for health damages and the approval of chemical toxicity are known to be major impediments to viewing the bigger picture regarding this tragedy. The authors believe that experts need to consider a comprehensive perspective going beyond their individual research arena to gain a better understanding of this issue, especially since it was an alarm signal on ethics and the role of experts and scholars in Korean society. Besides the two professors arrested by the prosecutor's office, it should be remembered that medical doctors recommended patients use humidifiers and disinfectants, and the media was inactive in reporting on this issue. Furthermore, the current paucity of examination of the social and political implications of this tragedy calls for more active engagement by researchers in the humanities and social sciences. In this regard, this paper is a work of self-examination and self-criticism by the authors that could resonate with the overall academic community.

• Journal of Food Hygiene and Safety
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• v.20 no.3
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• pp.175-178
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• 2005

Clean Natural is a new disinfectant of which main components are propolis and wood vinegar from Quercus mongolica. To evauate the bacterial reverse mutation of Clean Watural, the in vitro Ames test using Salmonella typhimurium TA98, TA100, TA102, TA1535 and TA1537 were performed with clean natural at the concentrations 0, 5, 2.5, and 1.25 mg/ml/plate. Clean Natural was negative in Ames test with Salmonella typhymuyium with and without rat liver microsomal enzyme (S-9 fraction). These results indicate that Clean Watural does not cause bacterial reverse mutation.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.6
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• pp.653-661
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• 2007

The Disinfectants/Disinfection By-products (D/DBP) Rule proposed by the US Environmental Protection Agency requires the implementation of enhanced coagulation as a control strategy for natural organic matter (NOM) removal and as a means of limiting the formation of all DBPs, i.e., not just the trihalomethanes and haloacetica acids. To control DBP formation, several best available technologies (BATs) were determined for removal of DBPs and DBP precursors. The enhanced coagulation is one of the BATs for DBP precursors removal. Treatment facilities that achieve a specified percent removal of total organic carbon (TOC) prior to the application of a continuous disinfectant or that achieve a residual TOC concentration < 2mg/L prior to the application of a continuous disinfectant are considered to be in compliance with enhanced coagulation. The enhanced coagulation was applied to raw water in Korea, the Han River. Raw water were examined and effects of different raw water qualities on enhanced coagulation were investigated. Three analyses were used for raw water characteristics, water quality measurement, molecular weight distributions, hydrophobic/hydrophilic fractionation. The Han River had the relatively low alkalinity and low organic carbon concentration. The results of molecular weight distributions showed significant portions of low molecular weight organics, which is very different from most water in USA. The alum doses for the required TOC removal guided from USEPA manual were quite low (i.e. 10~30 mg/L alum) for the water, probably due to the specific water quality of the Han River.

• Journal of Environmental Health Sciences
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• v.37 no.2
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• pp.133-140
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• 2011

Antimicrobial activity and bactericidal activity of Caesalpinia sappan L. extracts were investigated against five food-borne pathogens, E. coli, S. aureus, S. typhimurium, B. cereus and L. monocytogenes. Methanol extract of Caesalpinia sappan L. revealed antimicrobial activities against five pathogens. In particular, by paper disc diffusion the highest activity was shown against L. monocytogenes. Antimicrobial activities of methanol extracts showed the most potent activities, but hexane fraction had no activity. Fractions of ethyl acetate and butanol turned out to have higher antimicrobial activities against Gram(+) bacteria than Gram(-) bacteria. The minimum inhibitory concentration against five food-borne pathogens was 1.563 mg/ml on Gram(+) bacteria and 3.125 mg/ml on Gram(-) bacteria. The result of antimicrobial activity in a shaking flask method showed that bacterial growth rate fell by more than 99.999% at 3.125 mg/ml of methanol extract. The highest rate of viable reduction (99.998%) was shown at 0.781 mg/ml of methanol extract against L. monocytogenes. After five minutes of reaction between test strains and methanol extracts, the growth rates of five kinds of bacteria were reduced by more than 99.999% at a concentration of 100 mg/ml. Therefore, it is suggested that methanol extracts of Caesalpinia sappan L. can be developed as a natural sanitizer or disinfectant.