• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.3
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• pp.212-221
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• 2013

Objectives: Asbestos fibers are accumulated in negative pressure unit (NPU) or vacuum cleaner in asbestos removal. Failure of operation or poor use performance of the NPU or vacuum cleaner causes asbestos fibers to spread in the air. Asbestos contractors should have an NPU fitted with a HEPA , vacuum cleaner, decontamination area, respirators, wetting equipment, and differential pressure manometer to register with the Ministry of Employment and Labor. There should be performance criteria of equipment used in asbestos removal. But there are none such criteria used in asbestos removal. This study was performed to investigate international or national performance criteria of equipment used in asbestos removal. Methods: Regulations, approved code of practice, guidance and national standards of the UK, USA and Korea were reviewed. A survey was done to investigate the requirements for equipment used in asbestos removal in Korea. Results: Air flow of NPUs used in Korea usually covers from$500m^3/h$ to over $3000m^3/h$. Some requirements for NPUs used in Korea were missing compared to the requirements of British standards for NPUs. All NPUs have different missing requirements. The UK also has separate British standard for leak tests for NPUs. Highly hazardous class vacuum cleaners should be used in asbestos removal in the UK. It has national standards on the operation of vacuum cleaners used in asbestos removal. There is only a certification system for less than 2.5kw rated voltage vacuum cleaners for home use in Korea. Powered (-assisted) respirators with mask are recommended in asbestos removal. Type 5 coveralls should be used in asbestos removal in the UK. There are international standards for requirements and leak tests of type 5 coveralls. A manometer for measuring differential pressure is needed in asbestos removal. The manometer's measuring range should cover less than ${\pm}125$ Pa and the gradation of manometer should be less than 2.5 Pa. The definition of decontamination area should be corrected. Installation of airlock and minimum area should be considered in decontamination area. Conclusions: Equipment should be used in asbestos removal proper performance and no leaks. There should be a certification system for equipment used in asbestos removal. This study can help to a certification system for equipment used in asbestos removal in Korea.

• YAKHAK HOEJI
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• v.53 no.5
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• pp.274-280
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• 2009

To survey the status of quality control of major ingredients of 'Ssanghwatang (Oriental medicine used for fatigue)', we analyzed 1,024 samples (9 kinds) of medical herbs to determine amounts of ashes, acid-insoluble ashes, loss on drying that are major elements to ensure basic quality of herbal drugstuffs. After ash analysis, Paeoniae Radix (from China) failed to meet the herbal standard criterion. After yielding Z-score(indicating the probability of exceeding its criterion) Zizyphi Fructus, Zingiberis Rhizoma, Paeoniae Radix, Rehmanniae Radix Preparata became objects of intense quality control (=IQC). Analysis on loss on drying shows Cinnamomi Cortex was unsuitable and was put under the IQC. In case of respective heavy metals, Angelicae Gigantis Radix, Cnidii Rhizoma, Cinnamomi Cortex exceeded the maximum permissible range for Cd. The 3 kinds of sub-standards were put to the IQC. Statistic figures showed a significant correlation (t-test, p<0.01) between country-of-origin and sub-quality rates. Compared to domestic one, imported medicinal herbs were less suitable in regard of acid-insoluble ash, loss on drying and Pb/Hg content. Meanwhile, amounts of Acid-insoluble ash showed positive relation with amounts of Pb (r=0.202) and As (r=0.243) among heavy metals leading to an inference that herbs of which root/rhizome is used for medical purposes attribute its high heavy metal content to the fine earth/sand being stuck to its root stalk.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.11 no.1
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• pp.70-77
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• 2001

This study was conducted to identify the current status of occupational safety and health by checklist and to evaluate the airborne exposure to chemicals and to provide the appropriate recommendation for safety and health of laundries. A total of 20 laundries located in tile Gyungi district area were surveyed from July 20 to September 15, 2000. The prevalence of laundries having a stove and gas range were found to be 25 % and 55 %, respectively. Smoking is not allowed in 60 % of the laundries. Only 10 % of dry-cleaners were isolated. Ventilation systems in laundries had not been annually inspected. Most of the workers didn't put on respirators, MSDS were not available, and storage bottles did not contain warning labels. The bulk samples of dry cleaning agent include many chemicals that are not controlled by the MOL in Korea. The detected airborne organic solvents in the laundries were benzene, toluene, p-xylene, m-xylene, o-xylene, perchloroethylene, and 2-butoxy ethanol. The airborne concentrations of organic solvents were much less than the occupational exposure limits proposed by the Ministry of Labor(MOL) in Korea. But the concentrations of benzene exceeded the TLV of ACGIH. This study showed that the current status of occupational safety and health was not appropriate for workers in laundries. It is recommended that laundry workers should be educated for the treatment and storage of hazardous organic solvents to improve the occupational safety and health of the working environment as well as MSDS usage. Also, extended research and survey for the organic solvents that are not controlled by the MOL has to be conducted.

• Journal of the Korean Institute of Gas
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• v.22 no.4
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• pp.55-62
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• 2018

There is growing interest in solar power generation due to global warming. As a result, demand for polysilicon, which is the core material for solar cells, is increasing day by day. As the market grows, large and small accidents occurred in the production process. In 2013, hydrochloric acid leaked from the polysilicon manufacturing plant in SangJu. In 2014, a fire occurred at a polysilicon manufacturing plant in Yeosu, and in 2015, STC(Silicon Tetrachloride) leaked at a polysilicon manufacturing plant in Gunsan City. Leakage of chemicals in the polysilicon manufacturing process can affect not only the workplace but also the surrounding area. Therefore, in this study, we identified the hazardous materials used in the polysilicon manufacturing process and quantitatively estimate the amount of leakage and extent of damage when the worst case scenario is applied. As a result, the damage distance by explosion was estimated to be 726 m, and the damage distance to toxicity was estimated to be 4,500 m. And, if TCS(Trichlorosilane), STC(Silicon Tetrachloride), DCS(Dichlorosilane) leaks into the air and reacts with water to generate HCl, the damage distance is predicted to 5.7 km.

• Journal of Energy Engineering
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• v.28 no.4
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• pp.29-34
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• 2019

In this study, a quantitative risk assessment was carried out for a hydrogen complex station. The complex fueling station to be evaluated was hydrogen-LPG, and the components of each station were analyzed and the risk was evaluated. The final risk is assessed by individual and societal risks, taking into account the impact of damage and the frequency of accidents. As a result of individual risk calculation for the hydrogen-LPG fueling station that is the subject of this study, the hydrogen-LPG type fueling station does not show the unacceptable hazardous area (> 1 × 10E-3) proposed by HSE. The level of individual risk for both the public and the worker is within acceptable limits. In societal risk assessment, the model to be interpreted shows the distribution of risks in an acceptable range(ALARP, As Low As Reasonably Practicable). To ensure improved safety, we recommend regular inspections and checks for high-risk hydrogen reservoirs, dispensers, tube trailer leaks, and LPG vapor recovery lines.

• Journal of the Korean Institute of Gas
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• v.23 no.4
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• pp.46-64
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• 2019

Technical practice code, KGS GC101 2018, for explosion hazard area selection and distance calculation of gas facility was enacted and implemented from July 12, 2018. This code includes whole contents of IEC60079-10-1 2015 (Explosive atmospheres Part 10-1: Classification of areas - Explosive gas atmospheres), and clarifies the interpretation of ambiguous standards or adds guidelines for standards. KGS GC101 is a method for classifying explosion hazard place types: (1) Determination of leak grade (2) Determination of leakage hole size (3) Determination of leakage flow (4) Determination of dilution class (5) Determination of ventilation effectiveness, finally (6) Determination of danger place (7) Explosion The range of dangerous places can be estimated. In order to easily calculate this process, the program (KGS-HAC v1.14, C-2018-020632) composed by Visual Basic for Application (Excel) language was produced by Korea Gas Safety Corporation. We will discuss how to use codes and programs to select and set up explosion hazard zones for field users.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.308-316
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• 2020

This study attempted to derive an equation for calculating the damage impact distance using CARIS so that local governments can quickly determine evacuation and notification of residents in the event of an ammonia-release accident. Ammonia is an accident-causing substance and one of 16 substances to prepare for resident evacuation. It is the most frequently occurring chemical with 58 chemical accidents from 2014~2019. The study derives an equation for calculating the damage impact distance according to the exposure time of ammonia based on AEGL, an acute exposure standard applicable to the general population, which is includes vulnerable groups such as infants, children and the elderly and designated by the EPA. The calculation formulas for each concentration and exposure time to classify the hazardous area according to AEGL-3 and the semi-dangerous area according to AEGL-2 were derived. A comparison of the relative standard deviation between the damage impact distance values of CARIS revealed that is was in the range of 0~2%. Local governments should consider the actual accident situation and apply the appropriate damage-affected distance calculation formula derived from the study to evacuate residents near the origin of the accident or use for protective measures such as indoor evacuation notification.

• Journal of Korean Society for Quality Management
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• v.46 no.2
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• pp.301-310
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• 2018

Purpose: The purpose of this study is to investigate the effect of work intensity on fit factor and affective quality of the dustproof Background: Among the victims who suffer pneumoconiosis due to the inhalation of toxic substances or the lack of oxygen during the work, the proportion of the victims is larger than the other causes. Wearing a respirator may prevent pneumoconiosis, but it can be hazardous to workers because of the leakage through filters, cartridges, exhaust valves, broken parts, and face-to-face contact. Despite leakage through the contact area between the mask and the face has various causes such as the wearer's activity, sweat accumulation, facial shape, etc., There is a lack of relevant research and regulation compared to developed countries that have already institutionalized the law 30 years ago and give the right to sell through a test Method: The work intensity was adjusted by walking or running at 6km/h and 11km/h on the treadmill, and tasks were defined with reference to the test procedure and the exercise sequence applied in the face leakage test of the dustproof mask. And fit factor was measured objectively using 'Respirator Fit Tester 8038' which measures fit factor calculated by dividing the number of dust present outside the mask by inside the mask. In addition, affective quality was classified by the ease of use, ease of breathing, and ease of wearing, and was measured using the 5-point likert scale questionnaire. Results: There was a significant difference in fit factor, ease of breathing, and wearing convenience according to work intensity and no significant difference in ease of use(${\alpha}=0.01$). And when the work intensity was high, fit factor, ease of breathing, and wearing convenience were all lower than when the work intensity was low. Conclusion: In Korea, it is necessary to consider consideration of the work intensity when testing the leakage rate of the face part for safety certification of the respiratory protective equipment, When developing a mask, it should be possible to maintain high adhesion even under intense, active situation and high temperature conditions by selecting materials, improving the wearing style, and expanding the adjustable range.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.7
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• pp.858-863
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• 2020

We experimented with the particle-settling velocity and CHCl3 absorption efficiency of seven activated-carbon and analyzed seven heavy metal contents by elution for application to the field treatment of sunken HNS on the marine seabed. The mean particle-settling velocity was in the range 0.5-8 cm/s, except when the 8-20 mesh was used. The larger the HNS particle, the faster the particle-settling velocity was, and the CHCl3 absorption efficiency increased considerably owing to the larger surface area. In addition, the elution test results showed that the total Zn and As contents in >100-meshed activated carbon was higher than the contents criteria for the standard for water-treatment agents, and Cr, Zn, and As were released at higher concentrations than those released by other activated-carbon groups. Taken together, the CHCl3 absorption efficiency, settling velocity, and elution test results suggested that the 20-60, 20-40, and 2mm&down mesh activated-carbon adsorbents could be applied to the field treatment of HNSs and that the minimum required amount for field treatment were 0.82, 0.90, and 1.28 ton/㎘, respectively, as calculated based on the HNS-adsorption-capacity priority.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2017.11a
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• pp.79-85
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• 2017

It is critical that passengers should be given timely and correct escape or evacuation guidance from captain and crews when there are hazardous situations in a ship. Otherwise the consequences could be disastrous as "SEWOL Ferry" the South Korean passenger ship which sank in southern coastal area on 16th April 2014. Due to the captain's delayed evacuation decision and lack of sufficient number of crews to guide passengers' evacuation, the accident recorded many casualties, most of whom were high school students (302 passengers sank down with the ship while 172 rescued). Building a passenger ship with well-designed physical escape routes is one thing and guiding passengers to those escape routes in real disaster situation is another. Passengers get panic and move to a wrong direction, bottleneck makes situation worse, and even crews get panic also - passive static escape route signage and small number of trained crews might not be enough to take care of them. SESS (Smart Escape Support System) is being developed sponsored by South Korea Ministry of Ocean and Fisheries starting from 2016 with 4 years of roadmap. SESS comprises multiple active dynamic signage devices which communicate with real-time escape routing server software via LoRa (Long Range) proprietary wireless network.