• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.34 no.3
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• pp.262-278
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• 2024

Objectives: To investigate the work environment measurement (WEM) status and concentration levels of substances with short-term exposure limits (STEL) among special management substances. Methods: Data from the past 5 years of WEM for 6 substances (1,2-dichloropropane (1,2-DCP), 1,3-butadiene, benzene, trichloroethylene (TCE), perchloroethylene (PCE) and sulfuric acid) were analyzed. The number of samples and concentration level of STEL and 8-hour TWA (time weighted average) were compared. Results: The number of STEL measurement for 1,3-butadiene, benzene, and sulfuric acid was less than 1% of the number of TWA measurement samples, while TCE, 1,2-DCP, and PCE, which are mainly used for cleaning metals, were relatively high, at 16.1%, 5.6%, and 2.2%, respectively. When comparing the concentrations of STEL with TWA on the same STEL measured workers (STEL-matched TWA), STEL concentrations were 2.8, 3.1, 2.6, 2.6 and 40.5 times higher than TWA as 1,2-DCP, benzene, TCE, PCE, and sulfuric acid. When comparing the concentration of STEL-matched TWA with the total TWA, STEL-matched TWA was 3.4, 8, 1.4, 2.0, 8.6 and 0.7 times higher for 1,2-DCP, benzene, 1,3-butadiene, TCE, PCE, and sulfuric acid, respectively. Conclusions: This study found that the workers performing irregular tasks may be exposed to higher concentrations of hazardous substances than regular workers. It is necessary to strengthen short-term exposure measurement, even for substances which STEL have not been set.

• Bulletin of the Korean Space Science Society
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• 2000.04a
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• pp.17-17
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• 2000

No Abstract, See Full Text

• Bulletin of the Korean Space Science Society
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• 2001.11a
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• pp.38-38
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• 2001

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.1
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• pp.3-5
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• 2023

Objective: This study introduces exposure concentrations of time-weighted average standard (TWA) evaluation and short-time exposure standard (STEL) evaluation for trichloroethylene in the cleaning process. Methods: Trichloroethylene measurement was conducted according to the KOSHA Guide (A-24-2019) method. It was carried out twice. Results: As a result of the first measurement, TWA concentration exceeded 4 times the exposure standard and STEL concentration exceeded 16 times, but the inaccuracy and breakthrough of the collection time could not be considered, so the second measurement was conducted. The second measurement result was lower than the first measurement result, but exceeded the exposure standards (TWA, STEL). Conclusions: We were able to confirm that the exposure level of workers in the cleaning process using trichloroethylene exceeded the exposure standard. And it is also considered necessary to grasp the approximate concentration using a detector tube in the preliminary survey.

• Journal of Preventive Medicine and Public Health
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• v.21 no.1 s.23
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• pp.152-162
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• 1988

Benzene and toluene, which are widely used aromatic hydrocarbons in workplace, are recently proved to cause health hazards due to their toxic effects. This study investigated the influence of toluene on the urinary excretion of benzene metabolite by administering short term exposure limit(STEL) of these compounds(i.e., 13.8mg/kg of benzene and 108.8 mg/kg of toluene) intraperitoneally into Sprague-Dawley rats. After administration, urinary phenol concentration of rat was measured by gas chromatography for every three hours. Data were analyzed by non-parametric statistical methods using Kruskal-Wallis multi-sample test and Mann-Whitney U test. The following results were obtained : 1. Administration of STEL-benzene increased urinary phenol concentration in lats. 2. Urinary phenol concentration was increased logarithmically according to the dosage of benzene. 3. Excretion of phenol in urine was decreased when benzene and toluene were administered simultaneously compared with administering benzene alone. In summary, these results reveal that administration of STEL of toluene has antagonistic effect of urinary excretion of benzene metabolite in rats.

• 월간산업보건
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• s.275
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• pp.29-31
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• 2011

Perchloryl fluoride의 직업적 노출기준 TLV-TWA 3 ppm(13 $mg/m^3$)과 TLV-STEL 6 ppm (25 $mg/m^3$)은 hydrogen fluoride와의 구조 유사성을 근거로 권고하였다. 이 수준은 호흡기계 기관지 자극 가능성을 최소화하는 수준이며 이는 실험동물 연구를 기초하였다. Perchloryl fluoride에 노출된 개, 몰모트, 흰쥐 그리고 생쥐에서 유발된 독성 증상 및 징후는 폐충혈, 부종, 호흡곤란, 청색증 그리고 비장, 간, 신장, 골수에서의 혈철소증이다. TLV-STEL은 폐에 대한 악영향과 플루오르 침착증에 대한 안전을 좀 더 확보하기 위하여 권고하였다. "피부흡수(skin)"와 "감작제(SEN)" 그리고 발암성에 대한 경고주석을 설정하기에는 유용한 자료가 부족하다.

• 월간산업보건
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• s.256
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• pp.14-17
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• 2009

Pentaborane의 직업적 노출기준 TLV-TWA는 0.005 ppm(0.013 mg/m$^3$)으로 TLV-STEL은 0.015 ppm(0.039 mg/m$^3$)으로 권고하였다. 이 수준은 중추신경장애, 무감각, 운동장애, 근육 떨림 그리고 경련의 증상을 최소화하기 위한 것이다. TLV-STEL은 동물 독성실험에서 보고된 부정확한 노출농도에 대한 안전을 부가적으로 확보하기 위하여 권고하였다. 피부노출, SEN, 발알성 여부에 대한 노출 권고치는 충분한 데이터가 없어 현재 설정되지 않고 있다.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.8 no.1
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• pp.95-104
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• 1998

This Study was conducted at nine Histological Laboratories in the hospitals located in Seoul from August 20 to October 10, 1996. The main purpose of this study was to assess the TWA & STEL exposure to formaldehyde and to evaluate factors affecting formaldehyde concentration in Histological Laboratory. With evaluated factors, proper improvement strategy to minimize exposure was suggested. The results are summarized as follows ; 1. The TWA concentrations of the personal samples ranged from 0.02 to 3.86 ppm and that of one laboratory out of nine was exceeding 0.75 ppm, USA OSHA standard. The TWA concentrations of the area samples ranged from 0.08 ppm to 1.49 ppm and those of three laboratories out of nine were exceeding OSHA standard. 2. When measurement was conducted on the working tables. around Formaldehyde vessel, fixation container and storage cabinet, the geometric means of TWA concentrations were 0.62 ppm, 0.64 ppm. 0.58 ppm and 0.37 ppm respectively. 3. When overnight fixed specimens were examined, the STEL concentrations of personal samples ranged from 0.59 ppm to 5.01 ppm, those of three laboratories out of nine were exceeding 2 ppm, OSHA standard and the STEL concentrations of area samples ranged from 0.31 ppm to 3.08 ppm, those of four laboratories from nine were exceeding OSHA standard. 4. Factors affecting Formaldehyde exposure level were sanitation state of laboratory, volume of the room and opening state of fixation container & formaldehyde vessel(p<0.05).

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.31 no.3
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• pp.255-265
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• 2021

Objectives: The purpose of this study is to analyze the exposure characteristics of inorganic acids. Methods: We analyzed exposure data (n = 363,146) for six inorganic acids (hydrogen fluoride, hydrogen bromide, hydrogen chloride, phosphoric acid, nitric acid, and sulfuric acid) collected between 2017 and 2019 in South Korea. Measurement characteristics and exposure levels (ELs) were analyzed by inorganic acid, industry category, enterprise size, and measurement year. Results: Measurement percentage dominated in time-weighted average (TWA, 91%) compared to short term exposure limit (STEL) and Ceiling. Most of the measurements (79.7%) were collected from the manufacturing category of industry. Medians of ELs were mostly low (≤3% of the threshold limit), with the exception of sulfuric acid (4.6% of TWA and 10.5% of STEL). The percentages of exceeding 1% of the occupational exposure limits (OELs) in TWA were relatively high for sulfuric acid (35.8%) and hydrogen chloride (16.5%) compared to the other acids (4.2%-6.6%). In addition, the percentages of exceeding 1% of OELs in STEL or Ceiling were higher for sulfuric acid (22.9%), hydrogen chloride (12.3%), and nitric acid (8.2%) compared to the other acids (1.2%-1.9%). The small-sized enterprises showed higher ELs in TWA; contrarily, the large-sized enterprises had higher ELs in STEL or Ceiling. Conclusions: The measurement characteristics and ELs identified in this study could be useful for establishing safety and health policies for inorganic acids.

• Bulletin of the Korean Space Science Society
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• 1996.11a
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• pp.33-33
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• 1996