• Title/Summary/Keyword: Safety grade

Search Result 723, Processing Time 0.024 seconds

Case study of Hexavalent Chromium and Silica Exposure Assessment and Respiratory Fit-test for Paint Manufacturing Worker (페인트 제조 작업자의 6가 크롬 및 실리카 노출평가와 호흡보호구 밀착도 검사 사례)

  • Lee, Hyun Seok;Kim, Boowook
    • Journal of Korean Society of Occupational and Environmental Hygiene
    • /
    • v.31 no.4
    • /
    • pp.295-303
    • /
    • 2021
  • Objective: Paint manufacturing industry workers are exposed to various lung cancer carcinogenic substances including hexavalent chromium and crystalline silica. Studies have been conducted on lung cancer in Paint manufacturing industry workers and the concentration of hexavalent chromium in paint industry; however, the concentration of crystalline silica and hexavalent chromium and cases of lung cancer in a single Paint factory has never been reported in Korea. Methods: To determine whether the cancer was related to his work environment, we assessed the level of exposure to carcinogens during pouring and mixing talc and pigment. In addition, a mask fit test was performed for the worker. Results: Analysis of talc and silica bulk powder materials showed that crystalline silica (quartz) was 5% in talc and 100% in silica. The green and yellow pigments contained 87% and 92% of lead chromate, respectively. Our quantitative analysis of pigment powder samples showed that the hexavalent chromium contents quantified in the green and yellow pigment samples were 87% and 92%, respectively. In order to estimate his exposure level of hexavalent chromium, we measured a personal exposure level of hexavalent chromium for a worker in accordance with the National Institute for Occupational Safety and Health #7605 method. The results showed that the worker was exposed to the high level of hexavalent chromium (0.033 mg m-3). In addition, the talc powder also contained 5% quartz, and the worker's exposure level to respirable quartz exceeded OEL. As a result of the respiratory protection fit test for workers, the overall Fit Factor was '15' when wearing a second-grade mask and '25' when wearing a first-grade mask, significantly lower than the US Occupational Safety and Health Agency (OSHA) pass value of "100". Conclusion: Workers who pouring and mixing powder materials such as talc or colored pigments in paint manufacturing company may be exposed to high concentrations of carcinogenic substances. These findings indicate that it is necessary to local ventilation system inspection, safety and health education for employers and workers, and periodically monitoring and manage the working environment.

A Numerical Analysis on the Stress Behavior Characteristics of a Pressure Vessel for Hydrogen Filling by FEM (유한요소법을 이용한 수소충전용 압력용기의 응력 거동특성에 관한 수치적 연구)

  • Chol, Seunghyun;Byonl, Sung Kwang;Kim, Yun Tae;Choi, Ha Young
    • Journal of the Korean Institute of Gas
    • /
    • v.26 no.3
    • /
    • pp.38-44
    • /
    • 2022
  • As the supply of hydrogen charging stations for hydrogen supply accelerates due to the hydrogen economy revitalization policy, the risk of accidents is also increasing. Since most hydrogen explosion accidents lead to major accidents, it is very important to secure safety when using hydrogen energy. In order to utilize hydrogen energy, it is essential to secure the safety of hydrogen storage containers used for production, storage, and transportation of liquid hydrogen. In this paper, in order to evaluate the structural safety of a hydrogen-filled pressure vessel, the behavioral characteristics of gas pressure were analyzed by finite element analysis. SA-372 Grade J / Class 70 was used for the material of the pressure vessel, and a hexahedral mesh was applied in the analysis model considering only the 1/4 shape because the pressure vessel is axisymmetric. A finite element analysis was performed at the maximum pressure using a hydrogen gas pressure vessel, and the von Mises stress, deformation, and strain energy density of the vessel were observed.

Ignition Ability of Flammable Materials by Human Body's Electrostatic Discharge by Type of Fabric (옷감 종류별 인체대전 정전기 방전에 의한 인화성물질 점화능력)

  • Jong Soo Hyun
    • Journal of the Korean Society of Safety
    • /
    • v.39 no.2
    • /
    • pp.1-8
    • /
    • 2024
  • Unwanted effects of electrostatic phenomena occur in various industries. Electrostatic problems originating from the human body in flammable atmospheres in the industry are especially concerning. A substantial volume of experimental data on the electrostatic charging voltages created on the human body owing to the rubbing of apparel were generated and reviewed during this study. The data were reviewed to determine whether the resultant charging levels of the human body are hazardous in flammable atmospheres. This study was conducted under several conditions, such as different fiber types used in apparel, shoe types, and relative humidities (RHs). The following conclusions were drawn in this study. ① The electrostatic charging levels of the human body owing to the rubbing of apparel increase with the increase in the surface resistances of apparel; however, the electrostatic charging levels may be different depending on the condition of the cloth surface. ② The discharging energy of 1.98-18.5 [mJ] from the human body exceeds the minimum ignition energy of most flammable materials, when removing an overcoat made of polyester, cotton and wool under severe conditions such as wearing height-raising shoes for men. ③ When removing antistatic apparel, the maximum discharging energy of 0.128 mJ from the human body is dangerous if the minimum ignition energy of the flammable material is between 10-5-10-4 [J] Grade; however, a minimum ignition energy of 10-3 J Grade of the flammable material is considered safe. ④ While wearing antistatic shoes, the electrostatic charging voltage generated in the human body when removing an overcoat is 30 V; therefore, wearing such shoes is a suitable countermeasure when handling flammable materials. However, the antistatic abilities of shoes reduce when thick socks are worn. ⑤ As RH increases, the electrostatic charging levels of the human body decrease. ⑥ The electrostatic charging levels of the human body from removing a cotton overcoat can ignite the majority of flammable materials when RH is less than 30% under severe conditions such as wearing height-raising shoes for men.

Knowledge and Attitude about Radiation Safety Management in Dental Hygiene Students (치위생과 학생의 방사선 안전관리에 대한 지식과 태도)

  • Ju, Jongwook;Mun, Wonsuk
    • Journal of The Korean Society of Integrative Medicine
    • /
    • v.6 no.3
    • /
    • pp.73-81
    • /
    • 2018
  • Purpose : This study identified knowledge, attitudes and behavior for radiation safety management of dental hygiene student. And to provide basic data for the development of effective education program for safety management for radiation protection. Methods : A questionnaire survey of questionnaires was conducted on the second and third grade dental hygiene students at three - year college in 'A' area of Gyeongnam province. The questionnaire of 37 items was used to investigate knowledge and attitude about radiation protection. The collected data were analyzed using frequency analysis, mean, standard deviation, t-test, ANOVA and pearson's correlation Analysis using the SPSS 21.0 program. Result : Results obtained from this study are as follows. 1. Knowledge level of radiation safety management by general characteristics showed statistically significant difference. 2. Radiation safety education knowledge score was higher in the case of radiation safety education(t=1.660, p<.05). 3. The radiation safety management attitude score was a statistically significant difference between the groups according to 'achievement' (F=1.660, p<.001). In the case of 'radiation protection facilities', there was a statistically significant difference between groups according to the recognition of radiation protection facilities (F=6.001, p<.001). 4. As a result of investigating the relationship between radiation safety management knowledge and attitude, the higher the knowledge level of radiation safety management, the higher the attitude(p<.001). Conclusion : Therefore, radiation safety management education should be organized systematically and it is required to improve not only safety management knowledge, attitude level but also action level.

Literature Review of the Safety Studies among Nursing Students (간호대학생 대상 안전 관련 국내 연구 동향)

  • Lee, Seonhye
    • The Journal of the Convergence on Culture Technology
    • /
    • v.8 no.1
    • /
    • pp.131-138
    • /
    • 2022
  • This study was to investigate the characteristics of nursing students' safety by reviewing literature reported in Korea. Methods: A total of 29 articles were selected by the combination with 'safety', 'safety*', 'patient safety', 'patient safety*' 'nursing students', and 'nursing * students' from the database(via DBpia, KCI, KISS, NANET, NDSL, NL, RISS). Results: Publication year of researchs are '2015-2019' 69.0%, publication journal 'non-nursing' 79.3%, mean of participants 242.4 persons, 'under 200 persons' 51.7%, number of participating area 'one region' 48.2%, number of participating schools 'over three schools' 42.3%, participating grade 'senior in colleges' 56.2%. Participant were calculated by G*Power and unapproved by Institutional Review of Board(IRB) were 58.6%. Most of statistics measures were 'regression' 75.9%, and authors' number were '2 co-authors' 58.6%. In keyword analysis, it has changed from knowledge-oriented to patient-centered. Conclusion: Future research will require research and policy support for the development of an integrated educational approach and intervention plan to strengthen the safety competency of nursing students.

Environmental fatigue correction factor model for domestic nuclear-grade low-alloy steel

  • Gao, Jun;Liu, Chang;Tan, Jibo;Zhang, Ziyu;Wu, Xinqiang;Han, En-Hou;Shen, Rui;Wang, Bingxi;Ke, Wei
    • Nuclear Engineering and Technology
    • /
    • v.53 no.8
    • /
    • pp.2600-2609
    • /
    • 2021
  • Low cycle fatigue behaviors of SA508-3 low-alloy steel were investigated in room-temperature air, high-temperature air and in light water reactor (LWR) water environments. The fatigue mean curve and design curve for the low-alloy steel are developed based on the fatigue data in room-temperature and high-temperature air. The environmental fatigue model for low-alloy steel is developed by the environmental fatigue correction factor (Fen) methodology based on the fatigue data in LWR water environments with the consideration of effects of strain rate, temperature, and dissolved oxygen concentration on the fatigue life.

Review of Heap leaching Technologies (더미 침출에 대한 소고)

  • 정승재;조종상;이재장
    • Resources Recycling
    • /
    • v.7 no.5
    • /
    • pp.3-12
    • /
    • 1998
  • The most recent research in precious metal processing is found in the increasing use of heap leaching for the extraction of gold from low grade ores and tailing dumps because heap leaching has several advantages compared to traditional milling. They include simplicity, lower capital and operating costs, faster starter-up time and environmental safety. In this paper, an attempt has been made to provide an overview of important factors involved in the implementation of heap leaching technology as a vehicle for gold extraction from its low grade ores. Brief discussions of the various important elements to this process has been made to ascertain the heap leaching characteristics, such as heap leaching chemistry, natural factors, ore preparation, heap and pad construction, solution collection system, pond system, metal extraction, and economical consideration.

Standardization for receive and supply of electric power facility of airport (공항 수.배전 설비 표준화)

  • 최홍규;원진희;송영주;조계술
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
    • /
    • 2003.11a
    • /
    • pp.349-354
    • /
    • 2003
  • Airport facility is infrastructure that become external creditworthiness and linear measure of country competitive power. Among them, receive and supply of electric power facility of airport is very important in peculiarity, trustability, safety side of airport. In this parer, sorted domestic airline as 4 classes by code to accomplish standardization for receive and supply of electric power facility of airport. And established justice and coverage about receive and supply of electric power facility using without any standard present and analyze problem for receive and supply of electric power facility of existing airport and presents standard. Finally, present standard single-line diagram by airport grade and system grade standard of receive and supply of electric power facility of airport.

  • PDF

Estimation of Thermal Aging Embrittlement of LWR Primary Pressure Boundary Components

  • Kim, Sunki;Kim, Yongsoo
    • Nuclear Engineering and Technology
    • /
    • v.30 no.6
    • /
    • pp.609-616
    • /
    • 1998
  • Cast duplex stainless steels are extensively used for primary pressure boundary components. These components are, however, embrittled due to the precipitation of $\alpha$' phase by spinodal decomposition and other processes when exposed to reactor operating temperature for a design lifetime or life extension conditions. This report presents a procedure for estimating the current condition and the residual life of safety-related stainless steel components by using ANL database and correlations. The database of Charpy impact energy suggests that CF-8M grade is the most susceptible to thermal aging and CF-3 grade is the least. Thus, the integrity of CF-8M alleys may be degraded seriously and the degree of deterioration may exceed acceptance limit after several years of service in the nuclear reactors.

  • PDF

Safety classification for frequently-used herbal medicines inducing toxic metabolites (독성대사체를 생성하는 다빈도사용 한약재의 안전성등급화 - 천궁, 당귀, 감초, 숙지황을 중심으로 -)

  • Park, Yeong-Chul;Lee, Sundong
    • Journal of Society of Preventive Korean Medicine
    • /
    • v.19 no.2
    • /
    • pp.123-133
    • /
    • 2015
  • The new formular for herbal medicine-safety classification in terms of evidence-based medicine was developed and applied to evaluate various herbal medicines in the previous study. This study is aimed to evaluate the frequently-used herbal medicines inducing toxic metabolites or reactive intermediates(RI), such as Ligusticum wallichii Franch, Angelica sinensis, Glycyrrhizae Radix, Rehmanniae Radix, based on 6 safety grades calculated from human equivalent dose(HED)-based MOS(margin of safety). HED-based MOS can be explained as the ratio of theoretical ALD(approximate lethal dose) of human as $LD_1$(lethal dose of 1%)/ clinical maximum dose as $ED_{99}$(Effective dose of 99%). The herbal medicine showing the ratio less than 1 belongs to Class 1, but the herbal medicine showing the ratio more than 500 belongs to Class 6 with the lowest toxicity. As a result, they were evaluated as class 2 for Angelica sinensis and Glycyrrhizae Radix, class 3 for Ligusticum wallichii Franch and Rehmanniae Radix. These resultant grades for 4 herbal medicines were lower than the grade expected under consideration that these herbal medicines are used very frequently in oriental clinics. These low grades would be due to their ingredients which is biotransformed to toxic metabolites.