Investigation of particle transfer to sampler covers during the transportation of samples.

This study investigated the effects of particle transfer to the covers of aerosol samplers during transportation of wood dust and welding fume samples. Wood dust samples were collected in a sanding chamber using four sampler types: closed-face cassettes (CFC), CFC with Accu-CAP inserts, disposable inhalable samplers (DIS), and Institute of Occupational Medicine (IOM). Welding fumes were collected in a walk-in chamber using the same samplers, with Solu-Sert replacing Accu-CAP. The samples were divided into two groups, with one group transported by air and the other by land. They were returned in the same manner and analyzed gravimetrically for wood dust and chemically for welding fumes. For wood dust, IOM showed a significantly higher percentage of particles transferred to the covers compared with the other samplers regardless of the transportation mode (p < 0.0001; 64% by air and 15% by land), while other samplers showed less than or close to 10% (3.5-12%). When the percentages of particle transfer to the covers were compared between the air and land transportation, both IOM and CFC samples showed differences between modes of transportation, while others did not. For welding fumes, most samples (61% of samples for copper [Cu] and 76% of samples for manganese [Mn]) showed nondetectable amounts of the analyte on the covers. For all samplers, the particle transfer to the covers for both transportation modes ranged from 0.2-33% for Cu and less than 4.5% for Mn. Overall, this study confirms that particle transfer to sampler covers during transport highly depends upon the transportation mode and sampler type for wood dust, whereas particle transfer seems minimal for welding fumes. The findings of this study are based on two materials and limited sample sizes. Further investigation considering different industry types and tasks, particle size ranges, and materials might be necessary. Nevertheless, occupational professionals should account for this transfer when handling and analyzing samples in practice.

Exposure Assessment for Toxic Hepatitis Caused by HCFC-123.

This case report attempts to present a case of acute toxic hepatitis in fire extinguisher manufacturing workers exposed to 2,2-dichloro-1,1,1-trifluoro-ethane (HCFC-123) in August 2017 in Korea. Twenty-two-year-old male workers were exposed to HCFC-123 for 1.5 hours one day and for 2.5 hours the other day, after which one worker died, and the other recovered after treatment. The workers were diagnosed with acute toxicity of hepatitis. However, exposure levels of HCFC-123 were not known with no work environment measurement done. Therefore, this study was conducted to estimate the exposure concentration of HCFC-123 via a job simulation experiment. In the simulation, the HCFC-123 exposure concentration was measured with the same working practice and working time as with the workers aforementioned. As a result, the workers who infused HCFC-123 into storage tanks were estimated to be exposed to HCFC-123 at a concentration of 20.65 ± 10.81 ppm, and a mean concentration of area samples within a working radius were estimated as 70.30 ± 18.10 ppm. Valve assembly workers working on valves of a fire extinguisher filled with HCFC-123 were exposed to HCFC-123 at concentrations of 91.65 ± 4.03 ppm and 115.55 ± 7.28 ppm, respectively, in the simulation, and area samples simulated within the working radius were also found to be high with concentrations of 122.75 ± 91.15 ppm and 126.80 ± 60.25 ppm, respectively. Nitrogen gas packing workers, who did not handle HCFC-123 directly, were exposed to the agent at a concentration of 71.80 ± 8.49 ppm. These results suggest that exposure to HCFC-123 at high concentrations for 1.5-2.5 hours caused acute toxic hepatitis in two workers.

HCFC-123-induced toxic hepatitis and death at a Korean fire extinguisher manufacturing facility: a case series.

BACKGROUND: Exposure to sustained high concentrations of HCFC-123 is known to be hepatotoxic. We report two simultaneous cases of toxic hepatitis related to exposure to 2,2-dichloro-1,1,1-trifluoroethane (HCFC-123), a common refrigerant, at a Korean fire extinguisher manufacturing facility. CASE PRESENTATION: Patients A and B were men aged 21 and 22 years, respectively, with no notable medical histories. They had recently started working for a manufacturer of fire extinguishers. During the third week of their employment, they visited the emergency center of a general hospital due to fever, lack of appetite, and general weakness. At the time of their visit, they were suspected as having hepatitis due to elevated aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), and total bilirubin levels and were hospitalized. However, as their condition did not improve, they were moved to a tertiary general hospital. After conservative treatment, one patient improved but the other died from acute hepatic failure. Assessments of the work environment showed that the short-term exposure levels of HCFC-123 for valve assembly processes were as high as 193.4 ppm. A transjugular liver biopsy was performed in patient A; the results indicated drug/toxin-induced liver injury (DILI). Given the lack of a medical history and the occupational exposure to high levels of HCFC-123, a hepatotoxic agent, the toxic hepatitis of the workers was likely related to HCFC-123 exposure. CONCLUSIONS: Work environment assessments have not included this agent. To the best of our knowledge, we are the first to report a case of death related to HCFC-123-induced liver damage. Our findings suggest that exposure standards and limits for HCFC-123 must be developed in Korea; work environments will have to be improved based on such standards.

The Quality Control Program for Industrial Hygiene Laboratories in Korea.

In 1992, the quality control program was introduced in Republic of Korea to improve the reliability of the work environment monitoring, which was introduced in the 1980s. The commission entrusted by the Ministry of Employment and Labor, the Occupational Safety and Health Research Institute has conducted the program for industrial hygiene laboratories including designated monitoring institutions and spontaneously participating agencies. The number of institutions that participated in the program has increased from 30 to 161. The initial conformance ratio in the participants was 43% (organic solvents) and 52% (metals). Thereafter, the conformance ratio increased rapidly and it has remained in a stable state at more than 89% since 1996. As subject materials, 13 kinds of organic solvents and 7 kinds of metals were used. To improve the capability of measurement and analysis of private institutions, educational courses were conducted annually. An assessment at the actual sites of participants was additionally introduced into the program in 2013. Thus, the program turned into a system that administrates the overall process of participants. For the future, the scope of target materials will be extended through additional items. Thus, the reliability of the results of the work environment monitoring is expected to increase accordingly.

Exposure Characteristics of Construction Painters to Organic Solvents.

BACKGROUND: Construction painters have not been studied well in terms of their hazards exposure. The objective of this study was to evaluate the exposure levels of total volatile organic compounds (TVOCs) for painters in the construction industry. METHODS: Activity-specific personal air samplings were carried out in three waterproofing activities [polyurethane (PU), asphalt, and cement mortar] and three painting activities (epoxy, oil based, and water based) by using organic-vapor-monitor passive-sampling devices. Gas chromatograph with flame ionization detector could be used for identifying and quantifying individual organic chemicals. The levels of TVOCs, by summing up 15 targeted substances, were expressed in exposure-index (EI) values. RESULTS: As arithmetic means in the order of concentration levels, the EIs of TVOCs in waterproofing works were 10.77, 2.42, 1.78, 1.68, 0.47, 0.07, and none detected (ND) for indoor PU-primer task, outdoor PU-primer task, outdoor PU-resin task, indoor PU-resin task, asphalt-primer task, asphalt-adhesive task, and cement-mortar task, respectively. The highest EI for painting works was 5.61 for indoor epoxy-primer task, followed by indoor epoxy-resin task (2.03), outdoor oil-based-spray-paint task (1.65), outdoor water-based-paint task (0.66), and indoor oil-based-paint task (0.15). Assuming that the operations were carried out continuously for 8 hours without breaks and by using the arithmetic means of EIs for each of the 12 tasks in this study, 58.3% (7 out of 12) exceeded the exposure limit of 100% (EI > 1.0), while 8.3% (1 out of 12) was in 50-100% of exposure limit (0.5 > EI > 1.0), and 4 tasks out of 12 were located in less than 50% of the limit range (EI < 0.5). CONCLUSION: From this study, we recognized that construction painters are exposed to various solvents, including carcinogens and reproductive toxins, and the levels of TVOC concentration in many of the painting tasks exceeded the exposure limits. Construction workers need to be protected from chemical agents during their painting works by using personal protective devices and/or work practice measures. Additional studies should focus on the exposure assessment of other hazards for construction workers, in order to identify high-risk tasks and to improve hazardous work environments.

Exposure to Volatile Organic Compounds and Possibility of Exposure to By-product Volatile Organic Compounds in Photolithography Processes in Semiconductor Manufacturing Factories.

OBJECTIVES: The purpose of this study was to measure the concentration of volatile organic compound (VOC)s originated from the chemicals used and/or derived from the original parental chemicals in the photolithography processes of semiconductor manufacturing factories. METHODS: A total of four photolithography processes in 4 Fabs at three different semiconductor manufacturing factories in Korea were selected for this study. This study investigated the types of chemicals used and generated during the photolithography process of each Fab, and the concentration levels of VOCs for each Fab. RESULTS: A variety of organic compounds such as ketone, alcohol, and acetate compounds as well as aromatic compounds were used as solvents and developing agents in the processes. Also, the generation of by-products, such as toluene and phenol, was identified through a thermal decomposition experiment performed on a photoresist. The VOC concentration levels in the processes were lower than 5% of the threshold limit value (TLV)s. However, the air contaminated with chemical substances generated during the processes was re-circulated through the ventilation system, thereby affecting the airborne VOC concentrations in the photolithography processes. CONCLUSION: Tens of organic compounds were being used in the photolithography processes, though the types of chemical used varied with the factory. Also, by-products, such as aromatic compounds, could be generated during photoresist patterning by exposure to light. Although the airborne VOC concentrations resulting from the processes were lower than 5% of the TLVs, employees still could be exposed directly or indirectly to various types of VOCs.