기류 가시화기법을 이용한 방해기류 방향과 속도에 따른 푸쉬풀 후드 효율 평가

송세욱 ( Se Wook Song ),김태형 ( Tae Hyeung Kim ),하현철 ( Hyun Chul Ha ),강호경 ( Ho Gyung Kang ) 한국산업위생학회 2005 한국산업보건학회지 Vol.15 No.1

A push pull hood system is frequently applied to control contaminants evaporated from an open surface tank in recent years. Efficiency of push pull hood system is affected by various parameters, such as cross draft, vessel shapes, size of tanks surface, liquid temperature, and so on. Among these, velocity of cross draft might be one of the most influencing factor for determining the ventilation efficiency. To take account of the effect of cross draft velocities over 0.38m/s, a flow adjustment of ±20% should be considered into the push and +20% into the pull flow system. Although there are many studies about the efficiency evaluation of push pull hood system based on CFDs (Computational Fluid Dynamics) and experiments, there have been no reports regarding the influence of velocities and direction of cross-draft on push-pull hood efficiency. This study was conducted to investigate the influence of cross draft direction and velocities on the capture efficiency of the push-pull ventilation system. Smoke visualization method was used along with mock-up of push-pull hood systems to verify the ventilation efficiency by experiments. When the cross-draft blew from the same origins of the push flows, the efficiency of the system was in it`s high value, but it was decreased significantly when the cross-draft came from the opposite side of push flows. Moreover, the efficiency of the system dramatically decreased when the cross-draft of open surface tank was faster than 0.4m/s.

개방조 후드가 설치된 도금작업장의 방해기류 측정

송세욱 ( Se Wook Song ),김태형 ( Tae Hyeung Kim ),하현철 ( Hyun Chul Ha ),홍좌령 ( Jwa Ryung Hong ) 한국산업위생학회 2004 한국산업보건학회지 Vol.14 No.3

Open surface tanks are used in a variety of industrial processes, such as picking and plating. Push-pull ventilation system is often the best and most energy efficient way to remove any contaminant which evaporates from the open surface tanks. Existing design guidelines are based on experimental and numerical works which is cannot easily be extended to different operating conditions. Contaminant removal efficiency of push-pull ventilation could be affected by various parameters, such as vessel shape, room location, cross draft, etc. Especially, the velocity of cross draft might be one of influencing factors for the effective ventilation. To account for the effect of cross draft in case of over 0.4m/s, a flow adjustment of ±20% should be designed into the push and +20% into the pull flow system. For effective design and installation of push-pull system, we must be consider the magnitude of Cross draft velocity. However, the cross draft velocity of workplace installed push-pull ventilation system were not measured yet. In this paper, we measured the cross draft and door/window face velocities in 8 surface treatment shops in which the push-pull type open surface tanks are generally used. Two-directional hot-wire anemometer was used to measure the velocities after checking the main direction of flow by using smoke-tube. The experiments were performed in both winter and summer since the flow patterns and the velocities were thought to show the quite different seasonal variations. Mean cross draft velocities of winter and summer were measured as 0.60m/s and 0.62m/s, respectively, which is over the operating range, 0.4m/s. In addition, the face velocities through doors and windows were measured as 1.38m/s and 1.79m/s, respectively. The measured cross draft velocity is somewhat higher than 0.4m/s which is recommended for the push-pull hood by ACGIH design guideline. This high cross draft velocity could destroy the hood flow in the push-pull hood system. Thus, it is imperative that the ACGIH design guide line should be modified in the near future.

중국산 해포석 내 석면 함유 유무 분석

송세욱 ( Se Wook Song ),정용현 ( Yong Hyun Chung ),한정희 ( Jeong Hee Han ) 한국산업위생학회 2013 한국산업보건학회지 Vol.23 No.3

Objectives: 21 sepiolite substances produced in China were investigated for the presence of asbestos in their materials. Materials and methods: In order to identify asbestos in sepiolite substances, test materials were analyzed using a transmission electron microscope equipped with energy dispersive X-ray spectrometer(TEM-EDS) for confirming their shape and components(atomic %). Results: Five of 21 sepiolte substances were asbestos-containing materials. Two chrysotile containing sepiolite proved to be asbestoscontaining materials, as did two chrysotile mixed with tremolite containing sepiolite. 16 sepiolite substances did not contain asbestos materials. Conclusions: When importing sepiolite substances, they must be analyzed to determine if there is asbestos in their materials.

과소/과잉노동과 근로환경

이경용 ( Kyung Yong Rhee ),송세욱 ( Se Wook Song ),김영선 ( Young Sun Kim ) 한국산업보건학회 2014 한국산업보건학회지 Vol.24 No.4

Objectives: The major objective of this paper is compare the exposure work hours and experieence of ill health symptoms among under and over employment and matched group. Workers with over employment have more exposed to hazards than that with under employment because that workers with over employment work more than those with ender employment. Methods: This study as heuristics one used the third Korean Working Conditions Survey done by Occupational Safety and Health Research Institute in 2011. The sample size is 50,023 economic active persons. Over and under employment were measured by matching method of preferred and actual work hours. The exposed work hours to hazards were measured according to 13 hazardous factors and the experience of ill health symptoms were scaled by the number of experienced 14 ill health symptoms. To compare the exposure and the symptoms experience were compared by mean difference test with F test. Results: The proportion of over employment in male employees is 32.1% and that in female employees is 29.3% and under employment rate is 11.2% in mae and 13.9% in female employees. There is significant difference of the rate of over and under emplyment among age groups, industrial sectors, occupational groups and the state of employment. The difference of the exposed work hours to hazards among under, over and matched group were statistically significant in all hazards by gender. The exposed work hours to hazards in over employment were more than those in under employment. The number of experienced symptoms in over employment is statistically significantly more than that in under employment. Conclusions: Workers with over employment may be vulnerable group in the criteria of hazard exposure and health status. The results have some implications and limitations because that this study is heuristic one. The mismatch of preferred and actual working hours may be unfavorable work condition that has impact on safety and health of workers. The impact mechanism may be investigated as future study, Because that this study used cross sectional survey data, some causal relationships cannot be evaluated.

포름알데히드 함유 화학제품의 MSDS 신뢰성 평가 연구

홍문기 ( Mun Ki Hong ),송세욱 ( Se Wook Song ),이권섭 ( Kwon Seob Lee ),최성봉 ( Sung Bong Choi ),이종한 ( Jong Han Lee ) 한국산업위생학회 2013 한국산업보건학회지 Vol.23 No.3

Objectives: Workers who use chemicals are exposed to safety accidents and occupational diseases. Employers are required to provide workers with Material Safety Data Sheets (MSDSs) in order to prevent accidents and diseases related to chemicals. Thus, it is very important to offer reliable MSDSs. In this paper, we assessed the reliability of MSDSs for chemicals including formaldehyde. Methods: To evaluate MSDS reliability, we collected 14 MSDSs and bulk samples from the chemical industry. MSDS reliability was evaluated by the completeness of details. In order to evaluate the adequacy of the formaldehyde contents in a mixture, bulk samples were collected and analyzed by HPLC. The result of Globally Harmonized System (GHS) classification was confirmed by identifying physical chemical properties, toxicology information and ecological information. Results: The result of the evaluation of 14 MSDSs showed 76.29% average reliability on each item, especially 53.9% average appropriate rate on hazard·risk classification. No chemicals failed to match between the content (%) in MSDSs and the result of analysis. Conclusions: To elevate MSDSs reliability, the certified education of MSDS drafters and reorganization of the MSDS circulation system is required.

사업장 MSDS 교육의 현실과 안전관리자의 MSDS 교육 프로그램에 관한 연구

김기웅(Ki-Woong Kim),박진우(Ji Woo Park),송세욱(Se Wook Song) 한국가스학회 2013 한국가스학회 학술대회논문집 Vol.2013 No.5

UN GHS 기준에 의한 국내 건강·환경유해성 분류기준 및 분류결과의 통일화 방안 연구

이권섭 ( Kwon Seob Lee ),이종한 ( Jong Han Lee ),송세욱 ( Se Wook Song ) 한국산업위생학회 2012 한국산업보건학회지 Vol.22 No.2

Objectives: This study was performed to provide harmonized guidelines on health and environmental classification criteria and its results of chemicals in Korea. Methods: Firstly, The history of GHS implementation in UN and Korea was reviewed. Secondly, the differences in classification criteria on health and environmental hazards among UN GHS and two Korean government agencies, Korea Ministry of Employment and Labour (KMoEL) and Korea Ministry of Environmental (KMoE). The classification results were compared between classifications of Korea Occupational Safety and Health Agency (KOSHA) based on KMoEL and classifications of Korea National Institute of Environmental Research (KNIER) based on KMoE. Finally, an inter-agency harmonization on the classification criteria and the results was suggested by comparing the classification results of 5 chemicals; Benzene, carbon disulfide, formaldehyde, toluene-2,4-diisocyanate, and trichloroethylene, Results: KMoEL and KMoE revised regulations on chemical management and published a Notices on GHS classification criteria according to UN GHS document. However, the hazard to the ozone layer contained in the latest edition of UN GHS document published in 2011 was not included yet. The differences in classifications of 5 chemicals between KOSHA and KNIER were 36.2% in health hazards and 23.4% in environmental hazards, respectively. In conclusion, we suggested that a new revision be needed to include newly contained hazard and inter-agency working party be organized to harmonize classification results.

산화네오디뮴(Nd2O3) 기도투여에 따른 흡입독성

김종규 ( Jong Kyu Kim ),강민구 ( Min Gu Kang ),김수진 ( Soo Jin Kim ),송세욱 ( Se Wook Song ) 한국산업위생학회 2014 한국산업보건학회지 Vol.24 No.3

Objectives: This study was performed to produce data on the pulmonary toxicity of neodymium oxide (Nd2O3) by intratracheal instillation. Methods: Two groups of rats were exposed to neodymium oxide by intratracheal instillation with doses of 0.5 mg and 2.0 mg, respectively. At two days, four weeks and 12 weeks after exposure, body weight change, organ weight change and histopathological change were observed. At 12 weeks after exposure, lung function change was measured. Results: The body weight of rats in the high concentration group decreased after 12 weeks by 4-5% compared with the control group. At four weeks and 12 weeks after the administration of neodymium oxide, the absolute weight of the lungs of the high concentration group were significantly increased when compared with the control group (p<0.05). At 12 weeks after the injection of neodymium oxide, breath frequency and respiratory minute volume were increased, but inhalation time and expiratory time were decreased. Bronchiolar epithelial hyperplasia, alveolar type Ⅱ cell hypertrophy/hyperplasia and foreign body granulomatous inflammation were observed in the high exposure group. Conclusions: Body weight decrease, lung absolute weight and breath frequency increase, and pathological lung change were all observed. We found that pulmonary toxicity of neodymium oxide nanoparticles by intratracheal instillation could be confirmed.

레조르시놀의 화재ㆍ폭발 위험성 평가

이근원(Keun Won Lee),최이락(Yi Rac Choi),송세욱(Se Wook Song) 한국가스학회 2013 한국가스학회지 Vol.17 No.4

레조르시놀은 목재 및 타이어용 접착제, 합성수지 염료의 원료 등으로 널리 사용되고 있다. 이 물질은 상온에서 흰색 결정으로 분진은 공기 중에서 폭발성 혼합물을 형성할 수 있고 밀폐 공간에서 열에 노출 되었을 경우 폭발 위험성이 있다고 알려져 있다. 본 연구에서는 레조르시놀 취급시 화재 및 폭발 사고 등의 예방을 위한 해당 물질의 열분석, 열안정성, 분진폭발특성 및 최소점화에너지 등의 화재ㆍ폭발위험 특성을 평가하였다. 이들 연구결과는 레조르시놀의 사용 및 취급 시 공정의 안전 정보로 활용될 수 있을 것이다. Resorcinol is widely used as a wood, tire adhesives, and a raw material of synthetic dye. This material with white crystals at room temperature, the particulates in the air can form explosive mixtures. It is known to be an explosion hazard when exposed to heat in a confined space. The study was evaluated fire and explosion characteristics of the resorcinol through thermal analysis, thermal stability, dust explosion characteristics, and the minimum ignition energy. From this study, it can be used to provide a safety information in the using and handling process of the resorcinol.

타코나이트 광산 공정에서의 실시간 질량측정기기와 실시간 수농도의 환산에 의한 질량농도와의 연관성

정은교 ( Eun Kyo Chung ),장재길 ( Jae Kil Jang ),송세욱 ( Se Wook Song ),김정호 ( Jeongho Kim ) 한국산업보건학회 2014 한국산업보건학회지 Vol.24 No.1

Objectives: The purposes of this study are to investigate workers`` exposures to respirable particles generated in taconite mines and to compare two metric methods for mass concentrations using direct-reading instruments. Methods: Air monitorings were conducted at six mines where subjects have been exposed primarily to particulate matters in crushing, concentrating, and pelletizing processes. Air samples were collected during 4 hours of the entire work shift for similarly exposure groups(SEGs) of nine jobs(N=37). Following instruments were employed to evaluate the workplace: a nanoparticle aerosol monitor(particle size range; 10-1000 nm, unit: ㎛2/cc, Model 9000, TSI Inc.); DustTrak air monitors(PM10, PM2.5, unit: ㎎/㎥, Model 8520, TSI Inc.); a condensation particle counter(size range; 20-1000 nm, unit: #/cc, P-Trak 8525, TSI Inc.); and an optical particle counter(particle number by size range 0.3-25 ㎛, unit: #/cc, Aerotrak 9306, TSI Inc.). Results: The highest airborne concentration among SEGs was for furnace operator followed by pelletizing maintenance workers in number of particle and surface area, but not in mass concentrations. The geometric means of PM2.5 by the DustTrak and the Ptrak/Aerotrak were 0.04 mg/m3(GSD 2.52) and 0.07 mg/m3(GSD 2.60), respectively. Also, the geometric means of RPM by the DustTrak and the Ptrak/Aerotrak were 0.16 ㎎/㎥(GSD 2.24) and 0.32 ㎎/㎥(GSD 3.24), respectively. The Pearson correlation coefficient for DustTrak PM2.5 and Ptrak/Aerotrak PM2.5 was 0.56, and that of DustTrak RPM and Ptrak/Aerotrak RPM was 0.65, indicating a moderate positive association between the two sampling methods. Surface area and number concentration were highly correlated(R2 = 0.80), while PM2.5 and RPM were also statistically correlated each other(R2 = 0.79). Conclusions: The results suggest that it is possible to measure airborne particulates by mass concentrations or particle number concentrations using real-time instruments instead of using the DustTrak Aerosol monitor that monitor mass concentrations only.