• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.8 no.1
• /
• pp.105-114
• /
• 1998

In this study, 108 thinners were analyzed to identify their composition. The purposes of this study were to provide the data for MSDS and worker exposure levels. Thinners were collected from manufacturing industries, distributors and users. Wide ranges of thinner components were found ; Toluene, xylene, and ethyl benzene were most often found. Next, MIBK, cellosolve acetate, butyl cellosolve, and butyl acetate were found in 20-40 thinners. Others, such as acetone, n-hexane, cyclohexane, heptane, methylcyciohexane, octane and nonane were also found. There were about 5-6 components in each thinner. In the view point of Industrial Hygiene, Benzene was the most important component of thinners, which procures leukemia. Benzene was found from 8 kinds of thinners out of the total 108 surveyed. Thus, Content of benzene in thinners must be evaluated when industrial hygiene surveys are performed. Aromatic hydrocarbons were identified from 71 kinds of thinners out of total 108 and their contents were 10-87%. Alkanes were not contained in automobile painting, spraying, degreasing, urethane and epoxy thinners but lacquer, enamel and coating thinners.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.32 no.4
• /
• pp.340-349
• /
• 2022

Objectives: The importance of MSDS is emphasized for communicating hazardous information due to the increase in the types and usage of chemical substances. The purpose of this study is to assess the reliability of MSDS by collecting and examining paint thinners commercially available in South Korea. Methods: Twenty-five paint thinners were purchased at paint stores and the provision of MSDS was checked. Quantitative and qualitative analysis was performed on the chemical constituents of the thinners using GC-MSD and GC-FID. Reliability was evaluated by the MSDS collection rate for the paint thinners and calculating the rate of matching between laboratory analysis results and the contents and composition of chemical constituents given in the MSDS. Results: Unlike a study conducted in 2006, MSDS were provided for all 25 thinners. As a result of qualitative analysis using GC-MSD, 104 chemical substances were detected. The substances with the highest detection rate were identified in the order of toluene, butyl acetate, acetone, xylene, and ethyl benzene. A component matching rate of 41% was found by comparing the differences between the number of substances detected in laboratory testing and the number of substances listed in the MSDS. Benzene, a carcinogen not listed in the MSDS, was detected in two thinners produced by a small company. The detected benzene contents were 0.039 and 0.040%. When benzene is used, it should be strictly handled according to the Industrial Safety and Health Act. However, since it is not listed on the MSDS, it is judged that benzene was not being managed as a carcinogen in the workplaces where it is used. Conclusions: Since the reliability of MSDS, which play an important role in hazard communication, was evaluated to be low, it is necessary to systematically and continuously secure this reliability. In particular, carcinogens should be managed more strictly.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.16 no.4
• /
• pp.314-323
• /
• 2006

This study was conducted to identify ingredients of thinners and to confirm reliability of material safety data sheets (MSDS) of thinners for public and workers' health. The 41 thinner products were collected from paint shops located in Busan and Gyeongnam province. The 12 thinner products among them were identified using product MSDS. GC-MSD was used to analyze 41 kinds of thinners qualitatively and quantitatively. The 12 products MSDS were compared with thinner's component through qualitative analysis to confirm MSDS. Chemical ingredients, such as Benzene, Toluene, and Xylene etc., of thinners were analysed in quantity. The 41 thinner products contained 17 disclosed specific, trade name, or generically described chemical solvent ingredients. These 17 ingredients came under 6 classes: alcohols, aromatic hydrocarbons, esters, glycol ethers, ketones, and mixtures. These 17 ingredients were important in the view of industrial hygiene and had occupational exposure limit in the ambient, such as toluene, xylene, acetone, nonane, EGEE, heptane, cumene, MIBK, indene, tri-methyl benzene, etc, were found in 41 kinds of thinners. Aromatic hydrocarbons were the most identified ingredient in thinners. Especially, the benzene, which induces leukemia, was found in 4 kinds of thinners. The content rates of benzene in thinners were 0.25~1.18%. The benzene in enamel thinner, which were 0.39~0.72%, was highest from chemical classification. The contents of toluene, which was found from 27 kinds of thinners, were 5.35~64.16%, which were highest in sobu thinner as 58.80%. Xylene was found from 22 kinds of thinners and contents of xylene were 4.61~72.42%. Acrylic thinner's contents of xylene were 12.06~51.05%, which was most high. It was found that contents of benzene were increased and frequency of detection was decreased through comparison with other study. The MSDS possession rate of paint shops was low as 29.27%. So it did not provide information with public or workers. Mean of agreement rate between MSDS and components of thinners through qualitative analysis was 42.01% and it has wide range from 8.3% to 75%. There are many deficiencies in MSDS about component of thinners. In some case of sample, expecially, despite containing benzene, information was not written it on MSDS.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.9 no.1
• /
• pp.112-124
• /
• 1999

The purposes of this study were to provide the data for composition of ethylene glycol ethers and 2-ethoxyethyl acetate(EEA) exposure assessment of workers in various industrial operations. In this study, 80 thinners were analyzed to identify their composition and the air concentration of 2-ethoxyethyl acetate(EEA) and urinary 2-ethoxyacetic acid(EAA) were measured. In this study the subjects were the total of 183 drawn from 98 workers who were occupationally exposed to EEA and 85 workers who were not. The results were as follows: 1. There were found average 4.2 components in each thinner. 2. There were 90 components(26.9%) in ethylene glycol ethers of total of 334 detected organic solvents 3. Ethoxyethyl acetate, ethoxyethanol, buthoxyethanol, methoxy-ethanol were found in 30(37.5%), 27(33.8%), 19(23.8%), 2thinners(2.5%), respectively and their contents were average 18.5%. 4. Benzene was found 8 thinners(10.0%) of the total 80 surveyed. 5. In the electronic painting workers EEA exposure concentration was the highest, as showed 2.88ppm(0.01~15.1ppm), cases of exceeded threshold limit value(TLV=5ppm) were 7(10.6%) workers among the total of 98 exposed workers. 6. The geometric mean of urinary EEA in exposed workers was 1.61 mg/gcreatinine, and was higher than that of workers who were not exposed. In the electronic painting workers and offset printers, the geometric mean of urinary EAA was the highest showing 2.8 mg/gcreatinine. 7. The correlation coefficient between urinary concentration of EAA and air concentration of EEA was 0.90(P<0.05). The present results suggest that composition of ethylene glycol ethers in thinners must be evaluated when industrial hygiene surveys and biological monitoring are performed.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.7 no.2
• /
• pp.245-263
• /
• 1997

For twelve solvent thinners, evaporation rates of components were investigated and models to estimate the actual concentration have been evaluated. Also, the current ACGIH TLVs (Threshold Limit Values) for the concentration of organic mixtures have been adjusted. The results of this study are summarized as follows : 1. Airborne concentrations of solvent thinner components were related to their respective vapor pressure (r=0.96). On the other hand, there was no significant relation between the concentrations in the air of the thinner compounds and the original amount in liquid form. 2. Airborne concentrations of each chemical were estimated by temperature at $8.5{\pm}1$, $16.7{\pm}1$ and $31.5{\pm}2^{\circ}C$ with an air velocity of 1.5 m/s. The concentrations were increased by increasing temperature (p<0.05). The percentage of concentrations were proportionate to their respective percentage of vapor pressure. Among the chemicals studied, n-butyl acetate, n-butyl alcohol, m-xylene, p-xylene and o-xylene showed a clear relationship to temperature. 3. Airborne concentration of each chemical was estimated by air velocity at 0.05, 1.50 and 2.50 m/s, with a constant temperature at $17{\pm}2^{\circ}C$. The concentrations were increased by increasing air velocity (p<0.05). The percentage of concentrations were proportionate to their respective percentage of vapor pressure. Among the chemicals studied, n-butyl alcohol, m-xylene and p-xylene showed a clear relationship to velocity. 4. In estimating the concentrations of solvent thinners by temperature and air velocity, ACGIH TLVs for mixtures tended to be larger than the values obtained by ACGIH exposure index. It shows that ACGIH TLVs for mixtures are not adequate for evaluating the airborne concentration of thinners and other organic mixtures. 5. The evaporation rate of the thinners were compared to the theoretical equations of Hummel, Braun and Mackay. The Hummel and Braun methods were close to exposure index but Makay's showed an underestimated value. In order to see the accuracy of each three models, the SSE (Error Sum of Squares) calculated for Hummel's was 1.73, being the closest to the actual values. 6. Present ACGIH TLVs for mixtures are not appropriate evaluate industrial environments. In this study, a correction of TLVs using vapor pressure of respective components was suggested. In order to evaluate the corrected TLVs a paired t-test was performed. There was no significant difference between the exposure index and the concentration over suggested TLVs (p>0.05). Thus, this corrected TLVs seem appropriate in order to evaluate actual industrial workplaces organic chemical concentration in the air.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.9 no.1
• /
• pp.156-172
• /
• 1999

Potential chemical hazards encountered in painting operation of four shipyards and a ship-repair shop were investigated through the material safety data sheets (MSDS). Material safety data sheets (MSDS) for 307 paints, 50 thinners and 34 binders were collected and reviewed. It was shown that various organic solvents such as aromatic hydrocarbons, aliphatic hydrocarbons, ketones, alcohols, glycols, glycol ether acetates and esters were contained in painting materials. Of these solvents, xylene was found in the largest number of painting materials. sixty percent of the thinners contained xylene in the contents of 20-100%. Other most frequently found solvents were 1-methoxypropanol, 1-methoxypropyl acetate, n-butanol, methyl isobutyl ketone, toluene, isopropanol, and n-butyl acetate, etc. Glycol ethers such as 2-methoxyethanol (2-ME), 2-methoxyethyl acetate (2-MEA), 2-ethoxyethanol (2-EE), 2-ethoxyethyl acetate (2-EEA) and 2-butoxyethanol (2-BA) were regarded as having the potential to cause adverse reproductive effects, embryotoxic effect and hematotoxic effects, and were found in some epoxy panting materials. Coal tar pitch was included in some paints(13%) where polynuclear aromatic hydrocarbons (PAHs) could be contaminated. Inorganic pigments such as lead chromate and zinc potassium chromate were found in some paints (8%). The epoxy resin based paints, which may contain isocyanates such as toluene diisocyanates and hexamethylene diisocyanates causing potential sensitization and asthma to upper respiratory organ, were mostly used in the shipyards. The constituents in the MSDS were significantly different from the results analyzed using gas chromatography/mass detector: minor constituents or impurities were omitted in many MSDS. In conclusion, xylene was the most frequent organic solvent in painting materials, and glycol ethers, including 2-ME, 2-MEA, 2-EE, 2-EEA and 2-BA, were found some products. Also, painting workers may be exposed to PAHs, lead, chromate, isocyanates, organic tin and other various chemicals. The compositions of chemicals in painting materials were variable significantly, and the hazards were changed. These facts should be considered in environmental monitoring and control of the hazards.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.1 no.1
• /
• pp.8-15
• /
• 1991

In order to visualize the distribution of workplace of which mixed solvent level in air exceeded the TLV of 1.0 (ACGIH), 17 thinners used in 44 painting workplaces were analysed with gas chromatography, and their levels in air were compaired with. 1. For detection rate of solvents in thinner was highest in case of toluene (76.4%), and decreased in orders of xylene (70.6%), methylisobutyl ketone (35.3%), acetone (35.3%), methyl ethyl ketone (23.5%), isopropylacohol (17.6%), n-hexane (17.6%), styrene (11.8%), and ethylacetate (11.8%). Average number of solvents detected was 3.0. 2. Detection rates of organic solvent by component category was highest in cases of aromatic hydrocarbons (52.9%), and decreased in orders of ketones (31.4%), alcohols (5.9%), n-hexane (5.9%) and esters (3.9%). The rate by regulatory category, the second category component was detected in 93.9% of total. 3. There was significant correlation (r=0.929, p<0.01)between detection rates of solvents in thinner and in air. 4. Among the total of 44 painting workplace, the rate of them of which level of mixed solvents in air was exceeded was highest in case of aromatic hydrocarbons (29.5%), and decreased in orders of ketones (6.8%), alcohol (2.3%), n-hexane (2.3%), and was highest in guitar painting (71.4%) workplace in case of aromatic hydrocarbons by component category.

• Korean Journal of Environmental Agriculture
• /
• v.39 no.4
• /
• pp.360-367
• /
• 2020

BACKGROUND: The productivity and quality of blueberry (Vaccinium ashei Reade) greatly depend on the number of fruits in a plant. Especially, fruit set more than appropriate number negatively affects productivity and marketability due to the increased number of small fruits and delayed harvest time. This study was conducted to investigate proper timing and concentration for applying chemical blossom thinners such as ammonium thiosulfate (ATS) and UREA. METHODS AND RESULTS: ATS at 1.25% and 1.50%, and UREA at 6% and 8% were applied in four developmental stages, bud swell, pink bud, full bloom and petal fall. Fruit thinning rate was calculated based on the number of fruits harvested divided by that of flowers before applying blossom thinners. Ratios of leaf to flower and leaf to fruit were calculated based on the number of fully developed leaves in 25 days after full blossom divided by that of flowers or fruits, respectively. Chemical injury of leaves was investigated by calculating the number of leaves with chemical injury divided by the total number of leaves. Fruit thinning rates were 48% and 66% for UREA treatments at 6% and 8%, respectively, and 49% and 62% for ATS treatments at 1.25% and 1.50%, respectively, in the full bloom stage. In the petal fall stage, fruit thinning rates were 18% and 24% for UREA treatments at 6% and 8%, respectively, and 49% and 35% for ATS treatments at 1.25% and 1.50%, respectively. Leaf to fruit ratio (L/FR) increased by 109% and 188% compared to leaf to flower ratio in ATS treatments at 1.25% and 1.50%, respectively, and L/FR increased 93 and 196% in UREA treatments at 6% and 8%, respectively, in the full bloom stage. In the petal fall stage, leaf to fruit ratio increased by 60% to 100% in ATS treatments, but did not significantly differ from the control in UREA treatments. Fruit harvest was delayed in all treatments of all developmental stages except for 1.5% ATS and 6% UREA treatments at the petal fall stage, whose fruit harvest was two or three days faster than the control. CONCLUSION: The application of ATS and UREA for blossom thinning should be in the petal fall and full bloom stages for early and late harvest, respectively. Considering chemical injury, integrated harvesting and fruit size, however, it is appropriate to apply ATS at 1.5% in the petal fall stage to increase fruit productivity and quality in blueberry.

• Safety and Health at Work
• /
• v.14 no.4
• /
• pp.451-456
• /
• 2023

Background: We conducted a case-control study to identify high-risk occupations and exposure to occupational hazards for acute myeloid leukemia (AML). Methods: When patients with AML admitted to the Department of Hematology in the study hospital for the first time are referred to the Department of Occupational and Environmental Medicine, data on occupation are collected by investigators to evaluate work-relatedness. Community-based controls were recruited through an online survey agency, and four controls per case were matched. Occupational information was estimated using structured questionnaires covering 27 specific occupations and 32 exposure agents. Conditional logistic regression analysis was performed by pairing cases and controls. Results: In the analysis of the risk of AML according to occupational classification, a significant association was found in paint manufacturing or painting work (OR = 2.22, 95% CI: 1.03-4.81) and aircrew (OR = 6.00, 95% CI: 1.00-35.91) in males, and in pesticide industry (OR = 6.89, 95% CI: 1.69-28.07) and cokes and steel industry (OR = 2.00, 95% CI: 1.18-22.06) in ≥60 years old. Moreover, the risk of AML increased significantly as the cumulative exposure to thinners increased. In the analyses stratified by sex and age, the association between pesticide exposure and AML was significant in males (OR = 3.28, 95% CI: 1.10-9.77) and in ≥60 years old (OR = 6.22, 95% CI: 1.48-26.08). Conclusion: This case-control study identified high-risk occupational groups in the Republic of Korea including paint manufacturers and painters, aircrew, and those who are occupationally exposed to pesticides or paint thinners.

• Journal of Environmental Science International
• /
• v.25 no.8
• /
• pp.1177-1189
• /
• 2016

In order to prepare the information needed to construct a reduction system for volatile organic compounds (VOCs) exhausted from ship-block paint-booths in a giant shipyard, VOCs in paint-shop airs were analyzed and compared to the components in paint thinners. Aromatic hydrocarbons containing eight and nine carbon atoms are known to be major VOC compounds found in shipyard paint-shops. The total hydrocarbon (THC(C7)) concentrations calibrated using toluene gas, were measured in block paint-shops with two photo-ionization detector (PID) meters, and the resulting THC(C7) data were converted to THC(C1) concentrations according to the Standard Methods for the Measurements of Air Pollution in South Korea. THC(C1) concentrations near the spray site ranged from 10 to 2,000 ppm, but they were less than 400 ppm near the walls of the paint-booth. The measurements of THC concentrations, based on the height of the monitoring sites, were related to the height of the target to which the spray paints were applied. The maximum concentrations occurred at almost the same height as the spray targets. When painted blocks had been dried-by warming with no spraying, the THC concentrations were 80~100 ppm.