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Yong Hyun Chung - One of the best experts on this subject based on the ideXlab platform.
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subacute Inhalation Toxicity of cyclohexanone in b6c3f1 mice
Toxicological research, 2018Co-Authors: Yong Hyun Chung, Seoho ShinAbstract:Cyclohexanone (C6H10O, CAS No. 108-94-1) is a colorless oily liquid obtained through the oxidation of cyclohexane or dehydrogenation of phenol. It is used in the manufacture of adhesives, sealant chemicals, agricultural chemicals, paint and coating additives, solvent, electrical and electronic products, paints and coatings, photographic supplies, film, photochemicals, and as an intermediate in nylon production. Owing to the lack of information on repeated Inhalation Toxicity of cyclohexaone, in this study, we aimed to characterize the subacute Inhalation Toxicity. B6C3F1 mice were exposed to 0, 50, 150, and 250 ppm of cyclohexanone for 6 hr/day, 5 days/ week for 4 weeks via whole-body Inhalation in accordance with the OECD Test Guideline 412 (subacute Inhalation Toxicity: 28-day study). Mortality, clinical signs, body weights, food consumption, hematology, serum biochemistry, organ weights, as well as gross and histopathological findings were evaluated between the control and exposure groups. No mortality or remarkable clinical signs were observed during the study. No adverse effects on body weight, food consumption, hematology, serum biochemistry, and organ weights, gross or histopathological lesions were observed in any male or female mice in any of the exposure groups, although some statistically significant changes were observed in organ weights. We concluded that no observable adverse effect level (NOAEL) is above 250 ppm in mice exposed to cyclohexanone for 6 hr/day for 5 days/week.
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Inhalation Toxicity of bisphenol a and its effect on estrous cycle spatial learning and memory in rats upon whole body exposure
Toxicological research, 2017Co-Authors: Yong Hyun ChungAbstract:Bisphenol A (BPA) is a monomer used in a polymerization reaction in the production of polycarbonate plastics. It has been used in many consumer products, including plastics, polyvinyl chloride, food packaging, dental sealants, and thermal receipts. However, there is little information available on the Inhalation Toxicity of BPA. Therefore, the aim of this study was to determine its Inhalation Toxicity and effects on the estrous cycle, spatial learning, and memory. Sprague-Dawley rats were exposed to 0, 10, 30, and 90 mg/m3 BPA, 6 hr/day, 5 days/week for 8 weeks via whole-body Inhalation. Mortality, clinical signs, body weight, hematology, serum chemistry, estrous cycle parameters, performance in the Morris water maze test, and organ weights, as well as gross and histopathological findings, were compared between the control and BPA exposure groups. Statistically significant changes were observed in serum chemistry and organ weights upon exposure to BPA. However, there was no BPA-related toxic effect on the body weight, food consumption, hematology, serum chemistry, organ weights, estrous cycle, performance in the Morris water maze test, or gross or histopathological lesions in any male or female rats in the BPA exposure groups. In conclusion, the results of this study suggested that the no observable adverse effect level (NOAEL) for BPA in rats is above 90 mg/m3/6 hr/day, 5 days/week upon 8-week exposure. Furthermore, BPA did not affect the estrous cycle, spatial learning, or memory in rats.
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subacute Inhalation Toxicity of 3 methylpentane
Toxicological research, 2016Co-Authors: Yong Hyun Chung, Seoho ShinAbstract:3-Methylpentane (C6H14, CAS No. 96-14-0), isomer of hexane, is a colorless liquid originating naturally from petroleum or natural gas liquids. 3-Methylpentane has been used as a solvent in organic synthesis, as a lubricant, and as a raw material for producing carbon black. There is limited information available on the Inhalation Toxicity of 3-methylpentane, and the aim of this study was to determine its subacute Inhalation Toxicity. According to OECD Test Guideline 412 (subacute Inhalation Toxicity: 28-day study), Sprague Dawley rats were exposed to 0, 284, 1,135, and 4,540 ppm of 3-methylpentane for 6 hr/day, 5 days/week for 4 weeks via whole-body Inhalation. Mortality, clinical signs, body weights, food consumption, hematology, serum chemistry, organ weights, and gross and histopathological findings were compared between control and all exposure groups. No mortality or remarkable clinical signs were observed during the study. No gross or histopathological lesions, or adverse effects on body weight, food consumption, hematology, serum chemistry, and organ weights were observed in any male or female rats in all exposure groups, although some statistically significant changes were observed in food consumption, serum chemistry, and organ weights. In conclusion, the results of this study indicate that no observable adverse effect level (NOAEL) for 3-methylpentane above 4,540 ppm/6 hr/day, 5 days/week for rats.
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a study on subchronic Inhalation Toxicity of 1 chloropropane
Toxicological research, 2015Co-Authors: Yong Hyun ChungAbstract:This study was conducted to measure Toxicity of 1-chloropropane (CAS No. : 540-54-5). According to the OECD Test Guideline 413 (Subchronic Inhalation Toxicity: 90-day study), SD rats were exposed to 0, 310, 1,250, and 5,000 ppm of 1-chloropropane for 6 h/day, 5 day/week for 13 weeks via whole-body Inhalation. Mortality, clinical signs, body weights, food consumption, motor activity, ophthalmoscopy, hematology, serum chemistry, urinalysis, organ weights, gross and histopathological findings were compared between control and all tested groups. No mortality or remarkable clinical signs were examined during the study. No gross lesions or adverse effects on body weight, food consumption, motor activity, ophthalmoscopy, urinalysis, hematology, organ weights were observed in any of male or female rats in all tested groups. In serum biochemistry, glucose was significantly decreased in males of 1,250 and 5,000 ppm groups compared to control group in dose-dependent relationship. In histopathological examination, vacuolation of acinar cells was observed in pancreas of all male and female groups exposed to 1-chloropropane. In conclusion, no observable adverse effect level (NOAEL) was considered to be below 310 ppm/6 h/day, 5 day/week for rats.
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subchronic Inhalation Toxicity study of n pentane in rats
Safety and health at work, 2012Co-Authors: Yong Hyun Chung, Jeongsun YangAbstract:Objectives : This study was conducted in order to obtain information concerning the health hazards that may result from a 13 week Inhalation exposure of n -pentane in Sprague-Dawley rats. Methods : This study was conducted in accordance with the Organization for Economic Co-operation and Development (OECD) guidelines for the testing of chemicals No. 413 'Subchronic Inhalation Toxicity: 90-day study (as revised in 2009)'. The rats were divided into 4 groups (10 male and 10 female rats in each group), and were exposed to 0, 340, 1,530, and 6,885 ppm n -pentane in each exposure chamber for 6 hour/day, 5 days/week, for 13 weeks. All of the rats were sacrificed at the end of the treatment period. During the test period, clinical signs, mortality, body weights, food consumption, ophthalmoscopy, locomotion activity, urinalysis, hematology, serum biochemistry, gross findings, organ weights, and histopathology were assessed. Results : During the period of testing, there were no treatment related effects on the clinical findings, body weight, food consumption, ophthalmoscopy, urinalysis, hematology, serum biochemistry, gross findings, relative organ weight, and histopathological findings. Conclusion : The no-observable-adverse-effect level (NOAEL) of n -pentane is evaluated as being more than 6,885 ppm (20.3 mg/L) in both male and female rats. n -pentane was not a classified specific target organ Toxicity in the globally harmonized classification system (GHS).
Il Je Yu - One of the best experts on this subject based on the ideXlab platform.
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Long-Term Stability Characteristics of Metal Nanoparticle Generator Using Small Ceramic Heater for Inhalation Toxicity Studies
Inhalation Toxicology, 2020Co-Authors: Jun Ho Ji, Jae Hee Jung, Il Je YuAbstract:The use of silver nanoparticles is rapidly growing in various industries. However, exposure to nano-sized silver particles generated during production, use, and disposal in ambient air or the workplace remains an important concern for public and occupational health. There are currently no specific methods for measuring the Inhalation Toxicity of nanoparticles or specific nanoparticle generation methods. In a previous study, silver nanoparticles were generated using a small ceramic heater with a local heating area that allowed direct heating of the bulk silver source, thereby eliminating any space between the heating unit and the source material such that the volume of the nanoparticle generator and power consumption are both remarkably reduced. Therefore, to evaluate the efficacy of this nanoparticle generator for Inhalation Toxicity studies, the long-term particle generation characteristics were investigated, and the results confirmed a very stable continuous operation over 20-30 h. The geometric mean diameter and total number concentration of nanoparticles remained stable for about 24 h when the initial loaded mass of bulk silver on the heater surface was 160 mg. The particle size distribution after a long operating time was then estimated when changing the initial mass of bulk silver on the heater surface. It took about 36 h for the loaded silver mass to decrease from 160 mg to 100 mg, during which time the geometric mean diameter of the nanoparticles only decreased 6%, from 14 nm to 13.2 nm.
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Development of a Nose-only Inhalation Toxicity Test Chamber That Provides Four Exposure Concentrations of Nano-sized Particles.
Journal of Visualized Experiments, 2019Co-Authors: Jae-seong Yi, Kisoo Jeon, Ki-joon Jeon, Il Je YuAbstract:Using a numerical analysis based on computerized fluid dynamics, a nose-only Inhalation Toxicity chamber with four different exposure concentrations is designed and validated for flow field uniformity and cross-contamination among the exposure ports for each concentration. The designed flow field values are compared with the measured values from exposure ports located horizontally and vertically. For this purpose, nanoscale sodium chloride particles are generated as test particles and introduced to the Inhalation chamber to evaluate the cross-contamination and concentration maintenance among the chambers, for each concentration group. The results indicate that the designed multiconcentration Inhalation chamber can be used in animal Inhalation Toxicity testing without cross-contamination among concentration groups. Moreover, the designed multiconcentration Inhalation Toxicity chamber can also be converted to a single-concentration Inhalation chamber. Further testing with gas, organic vapor, or non-nanoscale particles will ensure the use of the chamber in the Inhalation testing of other test articles.
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acute Inhalation Toxicity of silver nanoparticles
Toxicology and Industrial Health, 2011Co-Authors: Jae Hyuck Sung, Kyung-hee Choi, Kyung Seuk Song, Jun Ho Ji, Il Je YuAbstract:The acute Inhalation Toxicity of silver nanoparticles was studied in Sprague-Dawley rats. Seven-week-old rats, weighing approximately 218 g (males) and 153 g (females), were divided into four groups (five rats in each group): fresh-air control, low-dose (0.94 × 106 particle/cm3, 76 µg/m3), middle-dose (1.64 × 106 particle/ cm3, 135 µg/m 3), and high-dose (3.08 × 106 particle/cm3, 750 µg/m3). The animals were then exposed to silver nanoparticles (average diameter 18-20 nm) for 4 hours in a whole-body Inhalation chamber. The experiment was conducted following Organization Economic Cooperation and Development (OECD) test guideline 403 with the application of good laboratory practice (GLP). In addition to mortality and clinical observations, the body weights, food consumption, and pulmonary function tests were recorded weekly. At the end of the study, the rats were subjected to a full necropsy, and the organ weights measured. The lung function was also measured twice per week after the initial 4-hour exposure...
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Acute and Subchronic Inhalation Toxicity of n-Octane in Rats
Safety and health at work, 2010Co-Authors: Jae Hyuck Sung, Il Je Yu, Byung-gil Choi, Min-won Baek, Young Kuk Choi, Kyung Seuk SongAbstract:Objectives: We have investigated the toxic effects of the Inhalation of subchronic and acute levels of n-octane. Methods: The rats were exposed to n-octane of 0, 2.34, 11.68 and 23.36 mg/L (n = 5 rats/group/gender) in an acute Inhalation test (Organization for Economic Co-operation and Development (OECD) TG 403), or to 0, 0.93, 2.62 and 7.48 mg/L (n = 10 rats/group/gender) for a subchronic Inhalation test (OECE TG 413), to establish a national chemical management system consistent with the Globally Harmonized Classification System (GHS). Results: Acutely-exposed rats became lethargic but recovered following discontinuation of Inhalation. Other clinical symptoms such as change of body weight and autopsy finds were absent. The LC50 for the acute Inhalation Toxicity of n-octane was determined to exceed 23.36 mg/L and the GHS category was ‘not grouping’. Subchronically-treated rats displayed no significant clinical and histopathological differences from untreated controls; also, target organs were affected hematologically, biochemically and pathologically. Therefore, the no observable adverse effect level was indicated as exceeding 7.48 mg/L and the GHS category was 'not grouping' for the specific target organ Toxicity upon repeated exposure. Conclusion: However, n-octane exposure should be controlled to be below the American Conference of Industrial Hygienists recommendation (300 ppm) to prevent Inhalation-related adverse health effects of workers.
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Numerical study on spatial distribution of silver nanoparticles inside whole-body type Inhalation Toxicity chamber
Journal of Mechanical Science and Technology, 2010Co-Authors: Atul Kulkarni, Jin Uk Yoon, Jae Hyuck Sung, Il Je YuAbstract:Silver nanoparticles are among the fastest growing product categories in the nanotechnology industry. Several experimental studies reported earlier for its Toxicity and its associated risks. Uniform distribution of nanoparticle concentration in Inhalation Toxicity exposure chambers is important in the conduct of Inhalation experimental evaluation. However, relatively little is known. Several factors, including nanoparticle size, degree of mixing, and chamber design, may influence the nanoparticles distribution in whole-body exposure chamber. In the present work we investigated numerically the silver nanoparticles concentration distribution and particle trajectory in the whole body Inhalation Toxicity test chamber. A three dimensional numerical simulation was performed using the commercially available computational fluid dynamics code Fluent with two models, discrete phase model (DPM) and fine particle model (FPM) to calculate spatial particle trajectories and concentration. The simulated results show that the silver nanoparticle trajectories and concentration distribution are dependent on Inhalation Toxicity chamber geometry.
Jun Ho Ji - One of the best experts on this subject based on the ideXlab platform.
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Long-Term Stability Characteristics of Metal Nanoparticle Generator Using Small Ceramic Heater for Inhalation Toxicity Studies
Inhalation Toxicology, 2020Co-Authors: Jun Ho Ji, Jae Hee Jung, Il Je YuAbstract:The use of silver nanoparticles is rapidly growing in various industries. However, exposure to nano-sized silver particles generated during production, use, and disposal in ambient air or the workplace remains an important concern for public and occupational health. There are currently no specific methods for measuring the Inhalation Toxicity of nanoparticles or specific nanoparticle generation methods. In a previous study, silver nanoparticles were generated using a small ceramic heater with a local heating area that allowed direct heating of the bulk silver source, thereby eliminating any space between the heating unit and the source material such that the volume of the nanoparticle generator and power consumption are both remarkably reduced. Therefore, to evaluate the efficacy of this nanoparticle generator for Inhalation Toxicity studies, the long-term particle generation characteristics were investigated, and the results confirmed a very stable continuous operation over 20-30 h. The geometric mean diameter and total number concentration of nanoparticles remained stable for about 24 h when the initial loaded mass of bulk silver on the heater surface was 160 mg. The particle size distribution after a long operating time was then estimated when changing the initial mass of bulk silver on the heater surface. It took about 36 h for the loaded silver mass to decrease from 160 mg to 100 mg, during which time the geometric mean diameter of the nanoparticles only decreased 6%, from 14 nm to 13.2 nm.
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acute Inhalation Toxicity of silver nanoparticles
Toxicology and Industrial Health, 2011Co-Authors: Jae Hyuck Sung, Kyung-hee Choi, Kyung Seuk Song, Jun Ho Ji, Il Je YuAbstract:The acute Inhalation Toxicity of silver nanoparticles was studied in Sprague-Dawley rats. Seven-week-old rats, weighing approximately 218 g (males) and 153 g (females), were divided into four groups (five rats in each group): fresh-air control, low-dose (0.94 × 106 particle/cm3, 76 µg/m3), middle-dose (1.64 × 106 particle/ cm3, 135 µg/m 3), and high-dose (3.08 × 106 particle/cm3, 750 µg/m3). The animals were then exposed to silver nanoparticles (average diameter 18-20 nm) for 4 hours in a whole-body Inhalation chamber. The experiment was conducted following Organization Economic Cooperation and Development (OECD) test guideline 403 with the application of good laboratory practice (GLP). In addition to mortality and clinical observations, the body weights, food consumption, and pulmonary function tests were recorded weekly. At the end of the study, the rats were subjected to a full necropsy, and the organ weights measured. The lung function was also measured twice per week after the initial 4-hour exposure...
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Subchronic Inhalation Toxicity of silver nanoparticles.
Toxicological Sciences, 2008Co-Authors: Jae Hyuck Sung, Jin Uk Yoon, Kisoo Jeon, Jun Ho Ji, Jung Duck Park, Moon Yong Song, Jayoung JeongAbstract:The subchronic Inhalation Toxicity of silver nanoparticles was studied in Sprague-Dawley rats. Eight-week-old rats, weighing approximately 253.2 g (males) and 162.6 g (females), were divided into four groups (10 rats in each group): fresh-air control, low dose (0.6 x 10(6) particle/cm(3), 49 microg/m(3)), middle dose (1.4 x 10(6) particle/cm(3), 133 microg/m(3)), and high dose (3.0 x 10(6) particle/cm(3), 515 microg/m(3)). The animals were exposed to silver nanoparticles (average diameter 18-19 nm) for 6 h/day, 5 days/week, for 13 weeks in a whole-body Inhalation chamber. In addition to mortality and clinical observations, body weight, food consumption, and pulmonary function tests were recorded weekly. At the end of the study, the rats were subjected to a full necropsy, blood samples were collected for hematology and clinical chemistry tests, and the organ weights were measured. Bile-duct hyperplasia in the liver increased dose dependently in both the male and female rats. Histopathological examinations indicated dose-dependent increases in lesions related to silver nanoparticle exposure, including mixed inflammatory cell infiltrate, chronic alveolar inflammation, and small granulomatous lesions. Target organs for silver nanoparticles were considered to be the lungs and liver in the male and female rats. No observable adverse effect level of 100 microg/m(3) is suggested from the experiments.
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long term stability characteristics of metal nanoparticle generator using small ceramic heater for Inhalation Toxicity studies
Inhalation Toxicology, 2007Co-Authors: Jun Ho Ji, Jae Hee Jung, Il Je YuAbstract:The use of silver nanoparticles is rapidly growing in various industries. However, exposure to nano-sized silver particles generated during production, use, and disposal in ambient air or the workplace remains an important concern for public and occupational health. There are currently no specific methods for measuring the Inhalation Toxicity of nanoparticles or specific nanoparticle generation methods. In a previous study, silver nanoparticles were generated using a small ceramic heater with a local heating area that allowed direct heating of the bulk silver source, thereby eliminating any space between the heating unit and the source material such that the volume of the nanoparticle generator and power consumption are both remarkably reduced. Therefore, to evaluate the efficacy of this nanoparticle generator for Inhalation Toxicity studies, the long-term particle generation characteristics were investigated, and the results confirmed a very stable continuous operation over 20–30 h. The geometric mean di...
Seoho Shin - One of the best experts on this subject based on the ideXlab platform.
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subacute Inhalation Toxicity of cyclohexanone in b6c3f1 mice
Toxicological research, 2018Co-Authors: Yong Hyun Chung, Seoho ShinAbstract:Cyclohexanone (C6H10O, CAS No. 108-94-1) is a colorless oily liquid obtained through the oxidation of cyclohexane or dehydrogenation of phenol. It is used in the manufacture of adhesives, sealant chemicals, agricultural chemicals, paint and coating additives, solvent, electrical and electronic products, paints and coatings, photographic supplies, film, photochemicals, and as an intermediate in nylon production. Owing to the lack of information on repeated Inhalation Toxicity of cyclohexaone, in this study, we aimed to characterize the subacute Inhalation Toxicity. B6C3F1 mice were exposed to 0, 50, 150, and 250 ppm of cyclohexanone for 6 hr/day, 5 days/ week for 4 weeks via whole-body Inhalation in accordance with the OECD Test Guideline 412 (subacute Inhalation Toxicity: 28-day study). Mortality, clinical signs, body weights, food consumption, hematology, serum biochemistry, organ weights, as well as gross and histopathological findings were evaluated between the control and exposure groups. No mortality or remarkable clinical signs were observed during the study. No adverse effects on body weight, food consumption, hematology, serum biochemistry, and organ weights, gross or histopathological lesions were observed in any male or female mice in any of the exposure groups, although some statistically significant changes were observed in organ weights. We concluded that no observable adverse effect level (NOAEL) is above 250 ppm in mice exposed to cyclohexanone for 6 hr/day for 5 days/week.
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subacute Inhalation Toxicity of 3 methylpentane
Toxicological research, 2016Co-Authors: Yong Hyun Chung, Seoho ShinAbstract:3-Methylpentane (C6H14, CAS No. 96-14-0), isomer of hexane, is a colorless liquid originating naturally from petroleum or natural gas liquids. 3-Methylpentane has been used as a solvent in organic synthesis, as a lubricant, and as a raw material for producing carbon black. There is limited information available on the Inhalation Toxicity of 3-methylpentane, and the aim of this study was to determine its subacute Inhalation Toxicity. According to OECD Test Guideline 412 (subacute Inhalation Toxicity: 28-day study), Sprague Dawley rats were exposed to 0, 284, 1,135, and 4,540 ppm of 3-methylpentane for 6 hr/day, 5 days/week for 4 weeks via whole-body Inhalation. Mortality, clinical signs, body weights, food consumption, hematology, serum chemistry, organ weights, and gross and histopathological findings were compared between control and all exposure groups. No mortality or remarkable clinical signs were observed during the study. No gross or histopathological lesions, or adverse effects on body weight, food consumption, hematology, serum chemistry, and organ weights were observed in any male or female rats in all exposure groups, although some statistically significant changes were observed in food consumption, serum chemistry, and organ weights. In conclusion, the results of this study indicate that no observable adverse effect level (NOAEL) for 3-methylpentane above 4,540 ppm/6 hr/day, 5 days/week for rats.
Shoji Fukushima - One of the best experts on this subject based on the ideXlab platform.
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thirteen week Inhalation Toxicity of 1 4 dioxane in rats
Inhalation Toxicology, 2008Co-Authors: Tatsuya Kasai, Misae Saito, Hideki Senoh, Yumi Umeda, Shigetoshi Aiso, Hisao Ohbayashi, Tomoshi Nishizawa, Kasuke Nagano, Shoji FukushimaAbstract:Thirteen-week Inhalation Toxicity of 1,4-dioxane was examined by repeated Inhalation exposure of male and female F344 rats to 0 (control), 100, 200, 400, 800, 1600, 3200, or 6400 ppm (v/v) 1,4-dioxane vapor for 6 h/day and 5 days/wk. All the 6400-ppm-exposed males and females died during the first week. Terminal body weight decreased, and relative weights of liver, kidney, and lung increased. AST increased in the 200 ppm-and 3200-ppm-exposed females, and ALT increased in the 3200-ppm-exposed males and females. Nuclear enlargement of nasal respiratory epithelial cells occurring in the 100-ppm-exposed males and females was the most sensitive, followed by the enlarged nuclei in the olfactory, tracheal, and bronchial epithelia. 1,4-Dioxane-induced liver lesions occurred at higher exposure concentrations than the nasal lesions did, and were characterized by single-cell necrosis and centrilobular swelling of hepatocytes in males and females. Glutathione S-transferase placental form (GST-P) positive liver foci w...