• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.762-767
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• 2009

Some types of semi-Volatile organic compounds (SVOC) that are emitted from plastics used in building materials and household appliances have associated health risks, even at low concentrations. In this study, micro chamber method for measuring SVOC is introduced and SVOC such as di (2-ethylhexyl) phthalate and butylated hydroxyltoluene emitted a flooring material were measured using a micro chamber method. Airflow characteristics in a micro test chamber deeply depended on air exchange rate. From the evaluation using an index of air change efficiency, such as the air age and the coefficient of air change performance, a fixed air exchange rate of $1.5\;h^{-1}$ in the micro chamber is desirable.

• Journal of the Korean Chemical Society
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• v.38 no.6
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• pp.418-426
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• 1994

This study was aimed at the detection of 40 semi-volatile organic base/neutral compounds from soil among 129 priority pollutants listed by EPA. Two extraction procedures, sonication extraction and Soxhlet extraction, were studied as a extraction and concentration method for priority pollutants in soil. Extracts were analyted by GC/MS-SIM(selected ion monitoring). The analytical methods were tested by standard compounds spiked into blank soil. Accuracy and precision of the methods were measured by calculation of mean recovery and mean relative standard deviation. And the method detection limits were estimated.

• Journal of Soil and Groundwater Environment
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• v.10 no.1
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• pp.6-12
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• 2005

Contamination of soils and groundwater by leakage of petroleum compounds from underground storage tanks (USTs) has become great environmental issues. Conventional methods such as soil vapor extraction (SVE) used for the remediation of unsaturated soils contaminated with volatile organic compounds might not be applied for the removal of semi-volatile organic compounds such as diesel fuels and PCBs, which have low volatility and high hydrophobicity. The objective of this study is to develop a hot air injection method to remove semi-volatile compounds. Additionally, operation parameters such as temperature, air flow rate, and water content are evaluated. Experimental results show that diesel ranged organics (DROs) are removed in the order of volatility of organic compounds. As expected, removal efficiency of organics is highly dependent on the temperature. It is considered that more than $90\%$ of organic contaminants whose carbon numbers range between 17 and 22 can be removed efficiently by the hot air injection-extraction method (modified SVE) over the $100^{\circ}C$. It is also found that increased air flow rate resulted in high removal rate of contaminants. However, air flow rate over 40 cc/min is not effective for the operation aspects, due to mass transfer limitation on the volatilization rate of the contaminants. The effect of the water content on the decane removal is minimal, but some components show large dependence on the removal efficiency with increasing water content.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.3
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• pp.280-287
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• 2009

High-tech microelectronics industry is known as one of the most chemical-intensive industries. In Korea, Microelectronics industry occupied 38% of export and 16% of working employees work in microelectronics industry. But, chemical information and health hazards of high-tech microelectronics manufacturing are poorly understood because of rapid development and its penchant for secrecy. We need to investigate on chemical use and exposure control. We Site-visits to 6 high-tech microelectronics manufacturing company which have cleanroom work using over 1,000kg organic solvents (5 semi-conductor chips and its related parts company, 1 liquid crystal display (LCD)). We reviewed their data on chemical use and ventilation system, and measured TVOCs (Total Volatile Organic Compounds) and carbon dioxide concentration. All cleanroom air passed through hepa filters to acheive low particle levels and only 1 cleanroom uses carbon filters to minimize the organic solvents exposures In TVOC screening test, Cleanroom for semi-conductor chips and its related parts company with laminar down flow system (e.g. class 1~100) showed nondetectable level of TVOCs concentration, but Cleanroom for liquid crystal display (LCD) with conventional flow system (e.g. class 1,000~10,000) showed 327 ppm as TVOCs. Acetone concentration in cleanroom for Jig cleaning, LC Injection, Sealing processes were 18.488ppm (n=14), 49.762 ppm (n=15), 8.656 ppm (n=14) as arithmetric mean. Acetone concentration in cleanroom for LCD inspection process was 40ppm (n=55) as geometric mean, where the range was 7.8~128.7ppm and weakly correlated with ventilation rate efficiency(r=0.44, p<0.05). To control organic solvents in cleanrooms, chemical and carbon filters should be installed with hepa filters. Even though their volatile organic compounds concentration was not exceed to occupational exposure limits, considering of entrance limited cleanroom environment, long-term period exposure effects and adverse health effects of cleanroom worker need further reseach.

• Analytical Science and Technology
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• v.25 no.1
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• pp.60-68
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• 2012

A gas chromatography-mass spectrometric (GC-MS) method was developed for determining 25 semivolatile organic compounds in water. A 1.0 L water sample was placed in a separatory funnel and saturated with NaCl, and the solution was extracted two times with 40 mL of methylene chloride. Under the established condition, the linear quantification range was 0.02-800 ng/L and the relative standard deviation was less than 15%. The method was used to analyze 16 surface water samples collected from various regions in Gum-River. The samples revealed SVOC concentrations in the range of 0.02-96.8 ng/L. Maximum concentrations of VOCs detected were not exceeded the EPA or Germany guidelines in any of the samples. The developed method may be valuable for monitoring SVOCs in water.

• Analytical Science and Technology
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• v.25 no.4
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• pp.236-241
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• 2012

There are many industrial factories in the central Nakdong river basin and have been occurred water pollution accidents by hazardous chemicals such as phenol, 1,4-dioxane and perchlorate. In this study, ten compounds of semi-volatile organic compounds (SVOCs) (dichlorvos, toluene-2,4-diisocyanate, 4,4'-methylenedianiline, 4,4'-methylenebis (2-chloroaniline), diethyl phthalate, di-n-butyl phthalate, butyl benzyl phthaltate, bis (2-ethylhexyl) adipate, benzophenone, 4,4'-bisphenol A) of hazardous chemicals which may be potentially discharged into the Nakdong river, were determined by gas chromatography-mass spectrometry (GC-MS) with disk-type solid-phase extraction. Accuracy and precision were in the range of 75.6~110.5%, and 4.6~12.7%, respectively and recovery was in the range of 72.4~127.9%. Three compounds (bis (2-ethylhexyl)adipate, benzophenone, 4,4'-bisphenol A) were detected in industrial wastewater such as wastewater treatment plants (WWTPs) and wastewater discharge facilities in the Nakdong River basin.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.32 no.2
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• pp.153-162
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• 2022

Objectives: Fused deposition modeling (FDM) 3D printer which is one of the material extrusion (MEX) technologies is an additive manufacturing (AM) process. 3D printers have been distributed widely in Korea, particularly in school and office, even at home. Several studies have shown that nanoparticles and volatile organic compounds (VOCs) were emitted from an FDM 3D printing process. The objective of this study was to identify types of chemicals possibly emitted from FDM 3D printing materials such as PLA (polylactic acid), ABS (acrylonitrile butadiene styrene), nylon, PETG (polyethylene terephthalate glycol), PVA (polyvinyl alcohol), PC (polycarbonate) filaments. Methods: 19 FDM 3D printing filaments which have been distributed in Korea were selected and analyzed VOCs emitted of 3D printing materials by headspace gas chromatography mass spectrometry (headspace GC-MS). Subsamples were put into a vial and heated up to 200℃ (500 rpm) during 20 minutes before analyzing FDM 3D printing filaments. Results: In the case of PLA filament, lactide and methyl methacrylate, the monomer components of one, were detected, and the volume ratio ranged 27~93%, 0.5~37% respectively. In the case of ABS filaments, styrene (50.5~59.1%), the monomer components of one, was detected. Several VOCs among acetaldehyde, toluene, ethylbenzene, xylene, etc were detected from each FDM 3D printing filaments. Conclusions: Several VOCs, semi-VOCs were emitted from FDM 3D printing filaments in this study and previous studies. Users were possibly exposed to ones so that we strongly believe that we recommend to install the ventilation system such as a local exhaust ventilation (LEV) when they operate the FDM 3D printers in a workplace.

• Journal of Environmental Health Sciences
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• v.48 no.2
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• pp.75-85
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• 2022

Background: Various types of semi-volatile organic compounds (SVOCs) exist in the public's living environment. They occur in different forms in terms of their physical and chemical properties and partition coefficients. As a consequence, indoor exposure to SVOCs occurs via various routes, including inhalation of air and airborne particles, skin contact, and dust intake. Objectives: To propose a method for assessing human exposure to the SVOCs occurring in the air of an indoor environment, the concentrations of SVOCs in house dust and organic films measured in a real residential environment were estimated in terms of gas-phase concentration using the partition coefficient. Assessment of inhalation exposure to SVOCs was performed using this method. Methods: Phthalates were collected from samples of house dust and organic films from 110 households in a real residential environment. To perform an exposures assessment of the phthalates present in organic films, gas-phase concentration was calculated using the partition coefficient. The airborne gas-phase concentrations of phthalates from the house dust and organic films were estimated and exposure assessment was performed based on the assumption of inhalation exposure from air. Results: As a result of the exposure assessment for gas-phase phthalates from house dust and organic films, preschool children showed the highest level of inhalation of phthalates, followed by school children, adults, and adolescents. Conclusions: This study includes the limitation of not considering different SVOCs exposure pathways in the health impact assessment, including those of phthalates in the indoor living environment. However, this study has the significance of performing exposure assessment based on exposure to SVOCs present in indoor air that originated from organic films in the indoor residential environment. Therefore, the results of this study should be useful as basic data for exposure and health risk assessments of SVOCs associated with organic films in the indoor environment.

• KSBB Journal
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• v.22 no.3
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• pp.174-178
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• 2007

The aim of this study was to identifyisothiocyanates (ITCs) from wasabi (Wasabi japonica Matsum) using supercritical carbon dioxide ($SCO_2$) and to compare the composition in the extracts between $SCO_2$ and organic solvents extraction. A semi-continuous high pressure apparatus was used to extract wasabi (roots, stems and leaves) at following conditions pressure 80$\sim$120 bar, temperature $40\sim50^{\circ}C$. Ether, ethanol, chloroform and dichloromethane were used as organic solvents. The ITCs extracted by means of both separation technologies were analyzed by a gas chromatography system. As the results of study, AITC and ITCs were highly extracted at 40$^{\circ}C$ and 80 bar. To extract AITC from wasabi, $SCO_2$ extraction is more effective than organic solvents extraction, resulted in thermal degeneration and remaining of organic solvents.

• Journal of Adhesion and Interface
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• v.7 no.2
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• pp.12-18
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• 2006

Recently, as industries and technologies are increased, superior adhesives having more and more developed functions and properties have been demanded. In this article, to use the merits and viscoelastic properties of poly(ethylene/butylene) rubber resin and to supplement the demerits, semi-structure pressure sensitive adhesives (PSAs) are developed. Aslo, it can be said environmentally friendly PSAs because of not use the organic solvent and not emit volatile organic compounds (VOCs).