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Korean Court in the Samsung Leukemia Cases - June 23, 2011

Seoul Administrative Court Division 14 Ruling


Case: 2010guhap1149 Motion to Vacate the Disposition for Denial of Dependency and Indemnity Compensation and Funeral Expenses, et al.


Plaintiffs: 1. Sanggi Hwang, 2. Seonwon Lee, 3. Aejeong Jeong, 4. Eungyeong Kim, 5. Changho Song


Defendant: Korea Workers’ Compensation and Welfare Service (President, Shin Young-Chul)


Defendant Joined Participant: Samsung Electronics Co. Ltd. (Chief Executive Officer, Ji-Sung Choice)


Pleading Concluded: May 23rd 2011


Decision Rendered: June 23rd, 2011






1.      The disposition for denial of dependency and indemnity compensation and funeral expenses rendered by the defendant is therefore vacated.

2.      Claim of Plaintiffs Aejeong Jeong, Eungyeong Kim, and Changho Song is dismissed.

3.      Except for the amount due to the joined participation to the proceedings, legal costs between Plaintiffs Sanggi Hwang and Seonwon Lee are to be borne by the concerned plaintiffs, respectively. Of the costs made by joined participation to the proceeding, the amount subject to Plaintiff Seonwon Lee and the defendant participant is to be borne by the defendant plaintiff, and the amount due to Plaintiff Aejeong Jeong, Eungyeong Kim, and Changho Song is to be borne by the plaintiffs, respectively.



Purport of Claim


Holding 1, as well as the disposition of denial of dependency and indemnity compensation and funeral expenses rendered by the defendant on May 15th 2009 to Plaintiff Aejeong Jeong, the disposition of the denial of convalescence rendered on May 15th, 2009 to Plaintiff Eungyeong Kim, and the disposition of the denial of convalescence rendered on Sept. 7th, 2009 to Plaintiff Changho Song are all vacated.




1.      Details of the Disposition

A.    Background of the Occupational Incident and Disease

(1)   The late Yumi Hwang died of the reasons below (born on April 21st, 1985), and plaintiff Sanggi Hwang is the father of the deceased.

Oct. 6th, 2003. Employed by the Defendant sub-participant (hereinafter participant) company

Jan. 2004 ~ Nov. 2004 In charge of Diffusion Process in Line 3 of Giheung plant site

Dec. 2004 ~ June 2005. In charge of Wet Etching Process in Line 3 of Giheung plant site

June 10th, 2005. Diagnosed with acute myeloid leukemia

March 6th, 2007 Died of acute myeloid leukemia


(2)   Late Sukyoung Lee (Born on Nov. 11th, 1976) died of the following reasons, and the plaintiff Seonwon Lee is the husband of the deceased.


Approx. Jan. 1995. Employed by the participant company

Jan. 1995 ~ June 2001. In charge of metal wiring process (spurt process) in Line 3 of Gihung plant site

July 2001 ~ June 2004. In charge of Chemical metalizing process in Line 3 of Gihung plant site

July 2004 ~ March 2005. In charge of labeling work in Line 3 of Gihung plant site

April 2005 ~ Aug. 2005. In charge of wet etching process in Line 3 of Gihung plant site

Sept. 2005. ~ March. 2006. In charge of diffusion process in Line 3 of Gihung plant site

April 2006. ~ June 2006. Maternity leave

July 2006. ~ In charge of wet etching process in Line 3 of Gihung plant site

July 13th 2006 Diagnosed with acute myeloid leukemia, died on Aug. 17th of the same year


(3)   Late Minwoong Hwang (born on Feb. 25th, 1975) died of the following reasons, and plaintiff Aejeong Jeong is the wife of the deceased.


Aprox. Nov. 1997. Employed by the participant company

Nov. 1997 ~ Aug. 2002 In charge of maintenance and repair within chemical mechanical polishing process in Line 5 of Gihung plant site

Sept. 2002 ~ In charge of setting-up, maintenance, and repair of new lines within back-lap process in Line 1 of Gihung plant site.

Oct. 27th 2004. Diagnosed with acute myeloid leukemia

July 23rd, 2005 Died of acute myeloid leukemia


(4)   Plaintiff Eungyeong Kim is diagnosed with acute myeloid leukemia from the following reasons.

Jan. 14th, 1991. Employed by the participant company

Jan. 14th 1991 ~ Feb. 1992 In charge of trimming and forming process in Bucheon plant site

March 1992 ~ Jan. 1996 In charge of trimming and forming process in Onyang plant site

Jan. 31st, 1996. Retired. Worked as housewife since.

Feb. 23rd, 2005. Diagnosed with acute myeloid leukemia


(5)   Plaintiff Changho Song is diagnosed with non-Hodgkin’s lymphoma from the following reasons.

May 24th, 1993. Employed by participant company

May 24th, 1993 ~ Dec. 30th, 1998. In charge of maintenance of plating equipment and chemicals within plating process in Onyang plant site.

Dec. 30th, 1998. Retired

Jan. 1999 ~ Dec. 2002. In charge of marking process in STS Semiconductor Communication Corp.

Oct. 2nd, 2008. Diagnosed with non-Hodgkin’s lymphoma


B.     Details of the Dispositions

Plaintiff Sanggi Hwang, Seonwon Lee, and Aejeong Jeong filed for dependency and indemnity compensation and funeral expenses, and plaintiff Eungyeong Kim and Changho Song filed for medical care expenses. Defendant, based on the reason that “the leukemia suffered by the late Yumi Hwang, Sukyoung Lee and Minwoong Hwang has no causal relationship with the work,” rejected the application for payment of dependency and indemnity compensation and funeral expenses by plaintiff Sanggi Hwang, Seonwon Lee, and Aejeong Jeong on May 15th, 2009, and rendered denial of convalescence disposition to plaintiff Eungyeong Kim on the same day and to plaintiff Changho Song on Sept.7th, 2009 (hereinafter ‘dispositions of this case’).


C.    The Production Process of Semiconductor by Participant

Participant’s semiconductor plant site is largely divided into Gihung site and Onyang site. Manufacturing of wafers, pattern generation, processing procedures are conducted in Gihung site, while cutting of wafers into chips, assembly, inspection process are conducted in Onyang site.


2.      Legality of the dispositions of this case, respectively

A.    Legality of the Disposition Rendered to Plaintiff Sanggi Hwang

(1)   Arguments made by Plaintiff Sanggi Hwang

Late Yumi Hwang worked in Line 3 of Gihung plant site of the participant company. While doing so,

①was exposed to ethylene oxide and ethylene-glycol-related chemicals such as benzene, phosphine, thinner, 2-methoxyethanol, while working in diffusion and wet etching processes, and;

②was exposed to substances including benzene and ethylene oxide while working in dummy wafer decapping process, and;

③was exposed to substances created in the midst of various other processes, especially including arsenic trioxide formed by chemical reaction of arsine used in implant process, as well as benzene used in optical phenomena as these substances were concentrated within the plant building due to the lack of ventilation, and;

④was exposed to radiation emitted from accelerated ion injector installed in the bay used in implant process front of which the plaintiff routinely walked while in work, and;

⑤was overworked under stress as was being subjected to frequent night shift and overtime while working in three shift which impeded biorhythm, and as a result of these working conditions and overwork, suffered from acute myeloid leukemia and died thereof, which renders the death of late Yumi Hwang a result of work-related accident. 


(2)   Facts Not Disputed

(A)  Current Condition of Gihung Plant Site

Gihung plant site consists of Gihun Complex (built in 1984, includes 9 wafer production lines) and Hwasung Compex (built in 2002, includes 6 wafer production lines), and as of Feb. 2008 the total number of workers in Gihung site is, approximately, 24,000, including 14,000 men (10,000 in production and 4,000 as desk workers) and 10,000 women (9,000 in production and 1,000 as desk workers).

(B)  The Contents of Late Yumi Hwang’s Work and etc

①Late Yumi Hwang, since entering participant company on Oct. 6th, 2003, was placed in Line 3 of Gihung plant site, had worked in Line 3 Bays 1, 22, and 24, respectively (diffusion process) and Line 3 Bay 3 (wet etching process).

②Diffusion process includes loading carriers that contain wafer on a loader and lifting them from a loader once the carriers pass through diffusion process and dispatching them for the subsequent processes. During this process, workers attach stickers that tell the state of processing and enter the date into the electronic data system. The diffusion process workplaces are sealed while receiving chemicals from external feeders via pipes. These chemicals are emitted to the outside using local ventilation system within the equipment. Within the lines in which the workers work top-down ventilation system is installed.

Late Yumi Hwang had worked in aforementioned diffusion process, and had in addition worked from time to time in decapping process of removing impurities on the surface of dummy wafers used in diffusion process as well.

③Etching process concerns the removing of pellicle on wafers except for the pellicle on the circuits drawn on them. Wet etching process uses chemical solution to etch. Bay 3 of Line 3 is where cleansing process in wet etching is carried out. It was built in 1988. Although currently all automatized, while late Yumi Hwang was working in that segment, manual, as well as automatic, facilities used. In a case where automatic facilities were installed, workers were in charge of uploading the carriers that contain wafers on a loader and shifting them once the carriers come out of cleansing process in the sealed automatic facilities. If manual facilities were used, the workers were to go inside of the sealed facilities and lifting the carriers once they complete cleansing process.

If manual facilities were used, workers were to cleans wafer carriers by repetitively soaking them in a bath containing hydrogen peroxide and BOE solvent for a certain amount of time manually, and subsequently, were to label them, input data into the electrical data system, and then dispatch the carriers to the following processes. Local ventilation system was installed on the both side of the upper part of the bath to emit the gas created from evaporation of the cleansing fluids.

Late Yumi Hwang worked in Line 3, Bay 3 of Gihung site from around Dec. 2004 to June 10th, 2005. Until March 20th, 2005 she worked in the cleansing process using manual facilities, after which she conducted the cleansing process in either manual or automatic process.

④Line 3 of Gihung site was equipped with safety system. However, workers routinely had to work with only dustproof work clothes, arm covers, and cotton masks in order to increase work efficiency, and the same was true for the late Yumi Hwang as well. The late Yumi Hwang worked with the late Sukyeong Lee in a group of two.

⑤The Late Yumi Hwang worked in three eight-hour shift amongst four groups (morning shift 06:00 ~ 14:00, day shift 14:00~ 22:00, night shift 22:00 ~ 06:00 of the following day). Extended works were not uncommon. She took two days off after 6 days of working, and her shift schedule changed in every eight days.



(C)  Use of Chemicals

①The participant made a note describing environmentally harmful substances (hereinafter ‘working environmental note’) and distributed it to engineers in the semiconductor manufacturing plant in January 1996 (refer to mentioned items in the ‘working environmental note’).


②The participant banned the use of 1,572 kinds of chemicals including benzene, formaldehyde, ethylene oxide and arsenic in the entire manufacturing process in June 2009.


③Ion Implantation in dophant implantation process is a process where an ion implanter is used to accelerate a doping atom so that it can be injected into a wafer, producing radiation as a by-product. Ion implanters were equipped with radiation shields, and the ion implanter in line no. 3 was located 80 meters away from the bay no. 3 where the late Yumi Hwang worked. 


④Each bay of the line no. 3 was wide open without entrance doors. Also, once gas leaked from one process, it spread out to other bays due to the air-circulation system in each line.


⑤The participant previously had inspection system only for gas leak inside the line for semiconductor manufacturing, and built additional inspection system for chemical compounds in June 2006.


⑥The participant identifies components of chemicals based on component labeling provided by suppliers. According to this labeling, chemicals do not contain carcinogenic materials, such as benzene. The sample analysis by the Educational-Industrial Institute of Seoul National University, however, showed a somewhat contradictory result. 


(D)  Health Condition of the Late Yumi Hwang

The late Yumi Hwang was healthy when entering the company and did not have family anamnesis.


(E)  The Result of the Epidemiological Investigation on the Workplace

The Occupational Safety and Health Research Institute (hereinafter ‘OSHRI’), an affiliated institute of Korea Occupational Safety and Health Agency, conducted a preliminary investigation on 22 May and 20 June 2007 at the request of the defendant. It measured working environments such as the department in which the late Yumi Hwang worked, from 17 to 21 September 2007 and completed a report after the deliberation by the Epidemiological Investigation and Analysis Council on 25 February 2009.


The Result of the Occupational Environmental Evaluation

The OSHRI conducted measurements on chemicals dealt in the line no. 3 of the plant in Giheung by collecting them from 9 different bays and measuring them for more than 6 hours a day. And then the OSHRI compared its concentration with the concentration standard for 8 hours’ exposure on the assumption that the exposure concentration during remaining hours will be the same as that during measured hours.


But in the case of the bay where organic solvents were measured, the investigator collected samples using manual sampling apparatus as well as area sampling. And the OSHRI compared manually collected samples with area samples. Also concerning a wet etching process in the bay no. 3, the measurement of short term exposure limit (STEL) was conducted for the duration of manual manufacturing.


To summarize, the amount of detected chemicals was very small, and benzene and archine, which are known to be carcinogenic, were detected.


The Result of the Previous Occupational Environmental Evaluation

The participant conducts an annual occupational environmental evaluation. According to the results of occupational environmental evaluations from 2001 to 2006, all chemical compounds are either undetected or detected to be below exposure limits.


Evaluation of Radiation Exposure

Radiation detectors were installed in 5 spots according to the location of ion implanters and movements of workers, so that they could measure the maximum dose of radiation which would be exposed to a worker for 8 hours a day.


As a result, the exposed doses from 4 spots were below the average exposed dose from natural radiation. The exposed dose from one spot was 2.4 uSv/hr, which means a worker is exposed to 4.8 mSv of radiation annually (he or she is assumed to work for 4o hours a week and for 50 weeks). The amount of radiation in the aforementioned spot did not go beyond the limit regulated under the Atomic Energy Law but it exceeded the exposed does of average people (1mSv/hr).


According to the radiographic exposure evaluation, if a worker is working in the spot with the highest radiation exposure for 8 hours a day, the probability of causation of radiogenic cancers is 0.53% at the 99th percentile. If exposed for 30 minutes a day, the probability is 0.03%. If exposed for 8 hours a day, the probability is 0.18% at the 50th percentile (median).


The Opinion of the Epidemiological Investigation and Analysis Council

The 13 members of the Council opined as following: 3 members concluded that the working environment had relevance to the death of the late Yumi Hwang; 1 member denied both the existence of evidence and that of obvious counterevidence; and 9 members concluded the relevance was low. Apart from the opinion of the Council, 2 members recommended by the family of the late Yumi Hwang opined that the working environment was relevant to the death. 


(F)   The Result of the Epidemiological Investigation on Workers in the Entire Workplaces


①The OSHRI conducted the epidemiological investigation on former and current workers in 6 semiconductor manufacturing companies and their subcontractors from the 1 January to 31 December 2008, in order to see whether the incidence rate of cancers in lymphohematopoietic system among them is higher than that among average people.





Standardized Mortality Ratio

(95% Confidential Interval)

Standardized Cancer Registration Ratio

(95% Confidential Interval)

Death (total)


Employment Insurance

0.53 (0.49-0.57)



Employment Insurance

0.66 (0.58-0.75)


Malignant Neoplasm


Employment Insurance

0.74 (0.63-0.86)

0.86 (0.77-0.95)


Employment Insurance

0.73 (0.57-0.93)

0.97 (0.87-1.09)

Cancers in Lymphohematopoietic System (total)


Employment Insurance

0.48 (0.23-0.88)


Personnel Data

0.41 (0.11-1.06)



Employment Insurance

0.92 (0.47-1.60)


Personnel Data

1.56 (0.68-3.08)




Employment Insurance

0.51 (0.19-1.12)

0.86 (0.48-1.42)

Personnel Data

0.36 (0.04-1.29)

0.87 (0.38-1.72)


Employment Insurance

0.89 (0.41-1.70)

1.04 (0.58-1.71)

Personnel Data

1.48 (0.54-3.22)

1.31 (0.57-2.59)

Non-Hodgkin’s Lymphoma


Employment Insurance

0.57 (0.16-1.47)

0.84 (0.45-1.44)

Personnel Data

0.62 (0.08-2.24)

0.77 (0.28-1.69)


Employment Insurance

1.05 (0.22-3.07)

1.61 (0.90-2.66)

Personnel Data

2.05 (0.25-7.42)



②According to the investigation of the OSHRI, 19 workers were diagnosed with cancers in lymphohematopoietic system (10 workers with leukemia, 8 workers with non-Hodgkin’s lymphoma, and 1 with Hodgkin’s disease, etc) among former and current workers in semiconductor manufacturing plants managed by the participant. Among those diagnosed with cancers, 7 died and one worker died of aplastic anemia, which is a kind of a lymphohematopoietic system disease.


(G)  The Result of Consultation of the Educational-Industrial Institute of Seoul National University


Domestic semiconductor manufacturers including the participant consulted the Educational-Industrial Institute of Seoul National University about the risk evaluation of semiconductor manufacturing plants in June 2009. The Institute conducted the investigation on the risk of plants for approximately 5 months, starting from June 2009.


Concerning the plant belonging to the participant, the Institute selected the line no. 5 of Giheung plant and the line no. 1 of Onyang plant and evaluated the risk of the above mentioned lines based on the result of occupational environmental evaluations done by the participant. The main content of the consultation report is as following.


Line no. 5 of Giheung Plant

(a) According to the labeling provided by suppliers, 99 chemicals are used in total (70 pure substances and 29 mixtures).


(b) 65 substances are bottled, 32 substances are centrally supplied through lines and 2 substances are stored in drums. The method of central supply has high possibility of spreading chemicals inside the plant, if gas is leaked through pipe connections. Also, the method of internal supply using bottles or cans has high possibility of gas leakage when containers are opened and shut, contents are divided into small portions and container are not adequately managed in storage.


(c) The actual identification and analysis of chemical substances demonstrate that 83 pure substances are used in total. Among them, compounds of 10 substances are unidentified and unknown as a trade secret. Also, only 24 out of the above-mentioned 83 substances are monitored in the occupational environmental evaluation. The unevaluated substances are not always safe, but need measuring to protect the health of workers in plants, especially concerning Catechol and ammonium hydroxide which are used in a washing process.


(d) The analysis of the distribution of maximum values of the exposure index of measured substances according to a process is shown in the chart no. 10 [the distribution of maximum exposure index according to a process (2007)]. In the chart, the distribution of the measured concentration of exposure received by workers and engineers was converted into the exposure index (exposure concentration / exposure limit). As the participant outsourced washing operation to subcontractors, the analysis of the distribution of maximum values of the exposure index of measured substance according to maintenance operation is provided in the chart no. 11 [the distribution of maximum exposure index according to maintenance operation (2007)].


(e) As operations to open, inspect and repair various devices are conducted regularly or irregularly inside semiconductor manufacturing plants, contaminants inside the devices can spread out inside plants during these operations and largely affect the exposure of workers. The current evaluation method, however, has some limitations in measuring occupational environments because it is an one-off evaluation on each process in each workplace only for the limited period of time.


(f) 323 gas detectors were installed in line devices in 6 process including a diffusion process in line no. 5, while 29 gas detectors were put outside the devices (inside the workplace). From February to July 2009, gas detector alarms went off 46 times in total. The list of generated alarms is shown in the chart no. 13 [list of generated alarms in line no. 5 during last 6 months]. Especially, when the alarm went off by the leakage of concentrated hydrogen bromide for 5,729 seconds on the 20 July 2009, no adequate measures such as evacuation of workers were taken to avoid the highly detrimental situation. 


(g) The chart below shows the analysis of chemical contents of 6 randomly selected liquid photosensitizers out of 50 ones used in a sensitization process in line no. 5. However, the very small amount of chemical substances was detected. Moreover, the concentration of air outside the chamber during the /regular operation would be under detectable limit as the local ventilation system was installed in the chamber of a sensitization process.  


(h) Dopants (such as archine, boron, phosphine, etc) which are exposed during ion implantation, are carcinogenic, explosive and combustible substances. Also, arsenic compounds which are produced as by-products when using archine, are causative agents for bladder cancer, skin cancer and leukemia.


(i) Concerning the evaluation of exposure degree according to job functions, it is necessary to combine exposure intensity and exposure frequency. First, concerning workers, the intensity of work-related exposure to harmful factors is low for the following reasons. Workers in lines are separated from facilities, devices and machines which generate harmful factors and are not engaged in repairing, washing and maintaining facilities. Also, the degree of their exposure to some risk factors is measured to be below the exposure limit. On the other hand, concerning engineers, the intensity of work-related exposure is high for the following reasons. Engineers are engaged in maintenance, washing and replacement of containers in separate chambers or rooms. Also, they are subject to an intense, short-term exposure according to research. In short, to combine exposure intensity calculated as above and exposure frequency is necessary to better evaluate exposure degree.



Onyang Plant

(a) While a total number of 343 chemicals are used, 2 substances are pure substances and 31 substances are mixtures. The participant identifies components of each chemical based on the component labeling provided by the suppliers.

(b) The most common way of supplying these chemicals are through bottles or cans, and this tends to result in ill management of chemicals during the process of opening and shutting chemical containers, dividing products into smaller portions, and storing portions within the factory.

(c) Actual identification and analysis of the above 33 chemical substances demonstrate that among the 63 pure substances used, 3 chemicals are unidentified and trade secrets. Also, only 14 chemicals out of 63 pure substances are monitored through the occupational environmental evaluation. The most commonly used chemical components are epoxy resin and phenolic resin. While the usage of these two chemicals can lead to the formation of formaldehyde through thermal degradation, methods of monitoring these materials are yet unknown.

(d) Table 7 shows the distribution of maximum exposure per process calculated in fractions contrasting exposure limit to exposure concentration.

(e) It is necessary to both evaluate exposure intensity and exposure frequency in order to determine degrees of exposure regarding different duties. Line workers’ intensity of exposure to harm factors can be classified as ‘low’. Engineers’ intensity of exposure can be classified as medium or high as they search for causes of problems in equipment or processing steps and take various measures such as replace chemicals, maintain equipment and replace parts in order to resolve these problems.

(f) The largest number of chemicals is used in the plating process. Engineers’ exposure to harm factors can be high since they clean and inject chemicals to plating baths and change filters for pumps that help circulate plating solutions; however, the overall degree of exposure is estimated to be low or medium when regarding actual work time committed to inserting chemicals. Tin, lead and acids such as sulfuric acid, nitric acid, and hydrochloric acid are chemicals that may harm workers’ health during the plating process.



(a) While an inflow of outside air constitutes 10 to 20 percent of the air (the rest being recirculating air) provided into wafer fabrication bays, outside are inflow is normally considered to be higher for manufacturing bays than wafer fabrication bays.

(b) Since the percentage of outside air inflow is only at 10 to 20 percent, there is a probability that leaked contaminants from equipment maintenance may circulate the wafer fabrication work area and the plenum. These contaminants may escape the notice of workers or leak detectors and cause chronic pollution that may negatively influence the workers’ health.


(H)   Medical Opinion on Cancers in the Hematopoietic System


Inheritance, benzene, 1,3-butadiene, ethylene oxide, anticancer drugs are known to be causes of acute myeloid leukemia. Smoking, petrochemicals, paints, corpse preservatives, herbicides, pesticides are also known to increase the danger of developing leukemia. Specific ionization radiation, asbestos, organic solvent such as trichloroethylene are suspected to cause cancer in the lymph hematopoietic system but have not been confirmed as tumor initiators. Recently formaldehyde has also begun to be classified as a suspected tumor initiator.

Ionizing radiation and benzene are known causes for acute lymphoblastic leukemia and exposure to toxic chemicals such as pesticides and smoking are known to increase the chance of development. Acute lymphoblastic leukemia is most common among ages 2 through 9 and usually occur before age 20.


Non-Hodgkin lymphoma tends to develop among agricultural workers, wood related industry workers, workers in synthetic rubber industries, workers in meat and metal industries, veterinarians, and workers treating asbestos. Dioxin, used in herbicides and pesticides, is a known risk factor, and study shows that benzene may also be related.


Ionizing radiation acts on the hematopoietic system and causes aplastic anemia and leukemia. In a study targeted towards survivors of the Japanese atomic bombings, incidence of myeloid leukemia increased 5 to 7 years after being exposed to ionizing radiation.


In 1987 the Occupational Safety and Health Administration(OSHA) lowered the threshold limit of benzene to 1ppm from 10ppm, and the American Conference of Governmental Industrial Hygienists(ACGIH) is encouraging the threshold limit to be lowered to 0.1ppm. In 1986 Korea limited benzene concentration to below 10ppm within the work area and has lowered this limit to below 1ppm since July 2003.


(3)   Judgment

(A)   The so called ‘accident on duty’ in the Industrial Accident Compensation Insurance Act describes occupational hazards caused by work related reasons. While a proximate causal relation between duty and occurrence of harm is necessary in order to be classified as an ‘accident on duty’, the claimant bears the burden of proving the causal relation between the employee’s duty and illness or the employee’s illness and death. In determining whether the employee’s duty and hazard are in a proximate causal relation, each employee’s specific health and physical conditions, rather than that of the average person, need to be considered.


However demonstrating a causal relation does not necessarily require medical or scientific reasoning. A proximate causal relation can be inferred from the employee’s health condition at the time of employment, the cause of disease, the existence of substances known to cause illness in the work place, and the period of employment. This inferred proximate casual relation between the employee’s duty and illness or death may serve as proof of causal relation.


(B)    According to the following reasons leading from the above finding of facts, even if the development process of the late Yumi Hwang’s acute myeloid leukemia has not been medically identified it can still be inferred that her exposure to various toxic chemicals during her work in the Giheung plant Line 3 developed or at least accelerated the development of acute myeloid leukemia; thus, a proximate causal relation between the late Yumi Hwang’s acute myeloid leukemia and her occupation seems considerable. Therefore plaintiff Sanggi Hwang’s argument is reasonable, and the defendant’s disposition based on opposite premises is illegitimate.


①While modern medical science does not accurately determine leukemia’s risk factors, ionizing radiation and certain chemicals such as benzene, 1,3-butadiene, ethylene oxide are known to cause leukemia. TCE and formaldehyde are also reported as risk factors of leukemia. Also the possibility of developing leukemia when exposed to toxic chemicals cannot be completely excluded even if it is without medical or scientific proof since it may be due to uninvestigated factors.


②After the participant company made and distributed the ‘working environmental note’ in 1996, the company started using dozens of chemicals in the third assembly line of the Giheung plant. The diffusion process includes the usage of hydrogen chloride and phosphorous oxychloride. Cleansing in the wet etching process requires the use of acetone, isopropyl alcohol, ACT-CMI, methyl chloride, TCE, various thinner, hydrogen peroxide, sulfuric acid, nitric acid, hydrofluoric acid, hydrogen chloride, phosphoric acid, acetic acid. These chemicals are stimulants to the eye, skin, and respiratory system. Among the above chemicals ACT-CMI, TCE, and sulfuric acid have been designated as carcinogens. TCE is suspected as a tumor initiator for cancers in the lymph hematopoietic system.


③Giheung plant line 5 and line 3 have similar working conditions, and the participant company uses 99 kinds of chemicals in line 5. Among them, 13 kinds are used in the diffusion process and 10 kinds in the cleansing process. A small portion of hydrogen chloride was also measured in the diffusion and cleansing process. While these chemicals are stimulants to the eye, skin and respiratory system, arsine and sulfuric acid are designated carcinogens(by the International Agency for Research on Cancer) and phosphine is known to cause leukopenia and anemia


Also the photosensitive process, procedure preceding the diffusion and wet etching process, requires the usage of a photosensitizer that was detected of benzene and 2-methoxyethanol. Benzene is a well-known risk factor for leukemia, and 2-methoxyethanol negatively influences the bone marrow.

Furthermore, the late Yumi Hwang seems to have used an unknown chemical product when working on the decap process for the dummy wafers used in the diffusion process.


④The result of the epidemiologic investigation shows that the toxic chemicals used in all processes may not have been under the threshold limit albeit the operation of Giheung plant Line 3’s ventilation system, the sealing of every facility and the installations of local ventilation systems within facilities. The late Yumi Hwang appears to have been exposed to a higher degree of toxic chemicals as she worked on a manual facility while cleansing for the wet etching process(the local ventilation system or top-down ventilation system seems to have been inadequate in discharging toxic chemicals). Also she may have been exposed from toxic chemicals emitted from other bays within the same line as each bay in Line 3 had open forms without doors that did not prevent air from traveling around through the ventilation system.


⑤Although the level of exposure was below the threshold limit, the late Yumi Hwang seems to have been continuously exposed to the above toxic chemicals as she was required to work under similar circumstances for long hours. Considering that Giheung plant’s third assembly had the most worn out facility, the late Yumi Hwang seems to have been exposed to a higher level of toxic chemicals than measured by the participant company.


⑥Study shows leukemia develops 5 to 6 years after overexposure to ionizing radiation; however, individuals may have different sensitivity to ionizing radiation and the late Yumi Hwang having been exposed to toxic chemicals for about a year and eight months may have had a combined effect. Therefore, personal difference in the level of immunity may have caused leukemia for the late Yumi Hwang albeit her short work period and below-the-standard exposure to toxic chemicals.


⑦However, it can be assumed that the workers in the semiconductor manufacturing plant are healthier than the general public, judging by the statistically meaningful result from an epidemiological investigation on the entire workers of the semiconductor manufacturing plant , that the standardized mortality ratio(hereinafter ‘SMR’) of each male and female workers are lower than that of the general public. Taking this into consideration, the fact that the SMR and the standardized incidence ratio(hereinafter ‘SIR’) of the female workers of the semiconductor plant are higher than that of the general public, back up the assumption that the occupational environment affected the development of leukemia of the late Yumi Hwang, although the results of the leukemia related SMR and SIR of the female workers aren’t statistically significant due to its wide confidence interval.


⑧The participant seems to have received a component analysis table that the chemical substances provided by the suppliers do not contain carcinogenic substance such as benzene etc. however, work-related accident of the Industrial Accident Compensation Insurance Act[1] does not require employer’s intention or negligence. Therefore, the above fact does not hinder admitting work-related accident. (Even though night shifts break biorhythms and extended hours are causation of overwork, the general opinion of the medical world is that biorhythms adapt to night shifts over a certain time and overwork does not cause cancer such as leukemia, therefore it is difficult to say they are the causation of the industrial accident of this case.)



B.     Legality of the Disposition Rendered to Plaintiff  Seonwon Lee.

(1)   The claim of the plaintiff Seonwon Lee

Apart from the fact of working in the chemical vapor deposition process, it is not so different from the claim of the plaintiff, Hwang, Sanggi.


(2)   Facts not disputed

(A)  Present condition of the Giheung plant

Same as 2.-A.-(2)-(A)


(B)  Work description of the late Sookyoung Lee

Not so different from 2.-A.(2)-(B) but worked in the metal wiring process and the chemical vapor deposition process.


(C)  Use of chemical substances

Same as 2.-A.(2)-(C)


(D)  Health condition of the late Sookyoung Lee

Medical examination results taken at the time of pregnancy and childbirth of the late Sookyoung Lee showed all normal, health examination results from 2003 to 2005 showed no particular disorder apart from the diagnosis of the need of vaccination of hepatitis type B, and no one in the family developed leukemia. However, the late Sookyoung Lee received treatment for inflammatory diseases such as chronic gastritis, chronic rhinitis, chronic vaginitis, contact dermatitis, acute bronchitis almost every year since around 1998. The late Sookyoung Lee gave normal childbirth in 2004.4 and took maternity leave until 2006.6, after which she returned to work then a few days later showed symptoms of bruised leg and bleeding gums and was diagnosed with acute myeloid leukemiafrom  Ajou University Hospital in 2006. 7. 13. She then received treatments for cancer but failed to recover and deceased in 2006. 8. 17.


(E)  Result of epidemiologic investigation

Same as 2.-A.(2)-(E)



(3)   Judgment

According to the “working environmental note”, argon is used in the metal wiring process and silane, diborane, phosphine, dichlorosilane etc. are used in the chemical vapor deposition process.

 Up to 99 kinds of chemical substances are used in line no. 5 where the occupational environment is similar to that of line no. 3 of Giheung plant, among which substances like hydrogen chloride are used in the metal wiring process, and nitric acid in the chemical vapor deposition process. Additionally, even though the extent of exposure to ionization radiation of the late Sookyoung Lee is not severe, the fact that she was exposed to various kinds of toxic chemicals for 10 years since around 1995 and that  she received treatment for skin ailment annually, show interaction with the exposure to ionization radiation. Therefore, the disposition against Lee, Seonwon of this case is illegitimate.



C.    Legality of the Disposition Rendered to PlaintiffAejeong Jeong

(1)   The claim of the plaintiff Aejeong Jeong

The late Minwoong Hwang worked in the Giheung plant of the participant’s company

①where he was exposed to toxic chemicals that develop in all the processes of the Back-lap process of line no. 1 during which he worked as an engineer,

②was exposed to various kinds of toxic chemicals that was left in the facilities during the facility washing operation,

③was exposed to silica, sulfuric acid etc. during the Slurry replacement operation,

④was also exposed to considerable amount of radiation, benzene, phosphine, ethylene oxide, sulfuric acid, arsine, arsenical etc. during the back-lap process installation routine in around 2002. 8,

⑤and furthermore, suffered from stress and overwork due to frequent night shifts and extended hours of breaking biorhythms in three shifts, which caused the development of acute lymphoblastic leukemia and the death of the late Minwoong Hwang, a work-related accident.


(2)   Facts not disputed

(A)  Present conditions of Gihueng plant

(B)  Work description of the late Minwoong Hwang


④The late Minwoong Hwang usually examined whether each facility worked normally for about 2hrs in the office or performed preliminary inspection, maintenance work for about 6hrs in the field.

During each process, the late Minwoong Hwang exchanged slurry basin used for wafer abrasive material. A slurry is composed of substances such as amorphous silica or amorphous steam silica, ammonia etc. and silica irritates eyes, skin and respiratory organ but is not designated a carcinogenic substance. Meanwhile, the participant periodically outsourced facility washing operation to subcontractors from 1995.


⑤The late Minwoong Hwang participated in the installation of the back-lap process for about 1 month around 2002.8 as he took charge of the back-lap process facility maintenance work. The installation work was mainly operated by the employees of the facility suppliers, and the engineers of the participant mainly observed the installation process or inspected the result of the individual operation when completed.


⑥The late Minwoong Hwang worked in 3 shifts 3 teams and often worked extended hours.


(C)  Use of Chemical substances

(D)  Health condition of the late Minwoong Hwang

(E)  The Result of the Epidemiological Investigation on the Workplace

testimony by those concerned on chemical substance leakage accident

 Workers who used to work in line no.3 testified that ‘leakage sensing facilities were often dismanteld in order to finish work as quickly as possible, and there were frequent chemical substance and gas leakage accident in the outdated pipeline and facility in line no.1, 2 and 3. Facility setup operation was performed on ground level and underground where in the latter, the worker should wear protective gear in preparation for toxic substance. But due to the character of the work coming and going, workers frequently did not wear protective gears. Engineers also performed facility washing operation’


The result of work environment evaluation


The result of the past work environment evaluation

There are no occupational environment evaluation results for the line no. 5 planarization process and the line no. 1 back-lap process, since the number of evaluation between 2002 and 2004 of the participant’s work environment was approved to be adjusted. In 2005, the back-lap process was not the object of the evaluation.


Evaluation of radiation exposure

Opinion of the evaluator of the epidemiological investigation


(F)   The result of the epidemiological investigation on the entire semiconductor plant


(3)   Judgment

According to the above facts, the following can be recognized that,

①there is the possibility of toxic chemical substance exposure of the late Minwoong Hwang, but since facility washing operation was performed by a subcontractor after 1995 and that the main installation of the back-lap and setup process was performed by the supplier, it is difficult to say that the deceased was in constant exposure,

②there is not enough reference on the direct exposure of toxic chemical substance or ionizing radiation that can be inducing factor of the acute lymphoblastic leukemia of the late Minwoong Hwang,

③according to the result of the epidemiological investigation on the entire semiconductor manufacturing plant, the SMR or the SIR of the entire lymph hematopoietic system cancer or leukemia of the male worker of the semiconductor plant in comparison with the general public shows no statistical significance, and its specific ratio shows no difference with the general public or rather appears lower,

④it is the general opinion of the medical world that night shift and overwork due to shiftwork are not inducing factors of leukiemia,

 and so it is difficult to say that the death of the late Minwoong Hwang is a work-related accident, leaving the disposition of the defendant on the plaintiff Jeong, Aejeong legitimate.



D.    The legitimacy of the disposition on the plaintiff  Eungyeong Kim

(1)   The claim of the plaintiff, Eungyeong Kim

Working in the cutting and bending process in the participant company’s Onyang  plant,

①inhaled toxic chemical substances in the cleaning process of the semiconductor chip with an air knife,

②inhaled the above solution while removing foreign substance on the semiconductor chip with the TCE,

③toxic chemical substance was absorbed through skin while cutting the semiconductor chip directly with hands,

④was exposed to gas and organic solvent used in manufacturing, plating and printing processes since all processes were operated in open space without distinction and the building itself was flawed,

⑤furthermore, suffered from stress and overwork due to frequent night shift and extended hours in 3 shift work, and due to the above work environment and overwork developed acute myeloid leukemia which is a work-related accident.



(2)   Facts not disputed

(A)  Situation in Onyang plant

Onyang plant was built around November 1991. Cutting wafers manufactured at Giheung plant, assembling them, and testing their performance, workers at this plant make the finished product of semiconductors. In February 2008, 6,200 workers were working at Onyang plant. Among them, 5,000 were blue-collar workers, and 1,200 were white-collar workers.


(B)  Tasks of Plaintiff Eungyeong Kim

Plaintiff Eungyeong Kim joined the participant company at 14 January 1991, and worked at Bucheon plant till February 1992. From March 1st, 1992, she began to work at Onyang plant.  She participated in trim & form processes until she left the participant company at 31 January 1996.

Building F at Onyang plant was an accessory building to line no. 2. When this building was newly constructed workings were not divided with partitions, so trim & form processes were progressed in open space alongside marking & plating processes.


②Plaintiff Eungyeong Kim cleaned molds with an air gun, installed semiconductor chips, and cut the chips with equipments. Then she bent the lead of semiconductor chips coming out of trim process with the shape of gull. If a chip was stained with foreign substance, she cleaned the chip with a cotton swab coated with TCE. And if she found an abnormal chip, like the one with wrongly bent lead, she straightened it with tweezers.


③Plaintiff Eungyeong Kim worked in three eight-hour shift amongst four groups. She often worked overtime, and took 2 or 3 days off in a month.


(C)  Use of Chemicals

①The participantdiscarded the entire quantity of TCE inside Onyang plant around 30 April 1995, and used 1,1,1-TCE instead as an organic solvent. The participant has been using HCFC-141b from the early days of 1996 till now.


②The only radioactive equipment at Onyang plant is located in the quality examination room[품질특성검사실], where chips are examined by using X-Ray. This equipment is equipped with radiation shields, and there is no other radioactive equipment in other processes. Plaintiff Eungyeong Kim’s work had no connection to the quality examination room.


③Unlike Giheung plant where wafers are manufactured, chemicals are not used in most processes at Onyang plant. Chemicals are used in some processes like plating process, but they are supplied from equipments which are installed outside, and local ventilation system is installed inside sealed equipments. Also, top-down or ceiling ventilation systems are installed inside the line.


(D)  Health Condition of Plaintiff Eungyeong Kim

(E)  The Result of the Epidemiological Investigation on the Participant’s plants

(F)   The Result of the Epidemiological Investigation on All Semiconductor Manufacturing Plants


(3)   Judgment

According to the following reasons that can be drawn from the previously approved facts,


①There is no sign to show that chemicals other than TCE were used as organic solvents in trim & plating processes, in which plaintiff Eunkueng Kim participated.


②It seems that TCE was used only until April 1995 at the participant’s Onyang plant, and that a different organic solvent was used since then.


③The main work of plaintiff Eungyeong Kim was putting a semiconductor chip on the equipment, taking out a processed chip and moving it to the next process. Cleaning chips and straightening leads seemed to be accessory to this main work.


④It is possible that chemicals used in other processes influenced Plaintiff Eungyeong Kim’s health to a certain extent, since trim & form processes were not divided from marking & plating processes with partitions when the participant’s Onyang plant started to operate. But it seems unlikely that such damage was being done continuously.


⑤Plaintiff Eungyeong Kim was diagnosed with acute myeloid leukemia 9 years after she left the participant company, and it is the general opinion of the medical world that night duty or overwork does not cause leukemia.


it is hard to judge plaintiff Eungyeong Kim’s disease as occupational incident and disease. Thus, the defendant’s disposition against plaintiff Eungyeong Kim is lawful.


E.     Legality of the Disposition Rendered to Plaintiff Changho Song

(1)   Arguments made by Plaintiff Sanggi Hwang

During working in plating process at Onyang plant of the participant company,


①Plaintiff Changho Song was exposed to lethal chemicals such as lead and TCE while changing plating chemicals[도금약품]and boiling them.


②Plaintiff Chango Song was also exposed to lethal chemicals used in other processes.


③Plaintiff Chango Song was under overwork and a lot of stress from many night duties and extended working hours while working an eight-hour shift. Since such work environment and overwork caused non-Hodgkin’s lymphomas, it comes under occupational incident and disease.


(2)   Approved facts

(A)  Situation in Onyang Plant

(B)  Tasks of Plaintiff Chango Song

①Plaintiff Chango Song had worked in plating process, line no. 2 at Onyang plant from 24 May 1993 to 30 December 1998, at which point he left Samsung Electronics Co Ltd.


②In plating process, molded semiconductors are electrically plated using solder bars made of tin and lead and nitric acid, in order to protect lead from outer environment like moisture and heat.

Plaintiff Chango Song inspected, maintained, and repaired the plating equipment in the plating process. He also replaced parts of the plating equipment. And he also did cleaning and preparing job called make-up, which is the work to clean the inside of tank of the plating equipment with a wet mop and to fill up plating chemicals[도금약품] in each tank.


③Plaintiff Changho Song worked in eight-hour shift amongst three groups. He often overworked, and took 2 or 3 days off in a month.


④After leaving the participant company in December 1998, plaintiff Chango Song worked in marking process at STS Semiconductor & telecommunications Co Ltd till December 2002.


(C)  Use of Chemicals


Unlike at Giheung plant, chemicals are not used in most processes at Onyang plant. As for tin and lead which are used in the plating process at Onyang plant, IARC(International Agency for Research on Cancer) is classifying lead as a Group II B substance (which means the evidence that this substance causes cancer in human is limited, and the evidence of causing cancer in animals is also not sufficient), and isn’t classifying tin as a carcinogenic substance.


(D)  Health Condition of Plaintiff Changho Song

(E)  The Result of the Epidemiological Investigation on the Participant’s plants

(F)   The Result of the Epidemiological Investigation on All Semiconductor Manufacturing Plants


(3)   Judgment

According to the following reasons that can be drawn from the previously approved facts,


①Though hydrochloric acid, nitric acid, lead, tin, et cetera are used in plating process at Onyang facility, and though plaintiff Changho Song seems to have been exposed to those toxic substances while doing his work such as filling up plating chemicals, none of those substances are identified as an immediate cause to non-Hodgkin’s lymphomas.


②There is no data to show that Changho Song was continuously exposed to the substances which are known or suspected as carcinogenic substances such as benzene and TCE.


③Plaintiff Chang Song continued working in the similar line of work for about 4 years after leaving the participant company


④Plaintiff Changho Song was diagnosed with non-Hodgkin’s lymphomas 9 years after he left the participant company, and it is the general opinion of the medical world that night duty or overwork due to shift work does not cause leukemia.


it is hard to judge plaintiff Changho Song’s disease as occupational incident and disease. Thus, the defendant’s disposition against plaintiff Changho Song is lawful.



3.      Conclusion

Therefore we uphold the claims of plaintiff Sangi Whang and Seonwon and dismiss the cases of plaintiff Aecheong Chung, Eungyeong Kim, and Chanho Song.



Presiding Judge Changsu Jin,

Justice Hyeongseop Gwak

Justice Seokhyeon Hong.





[1] 산업재해보상보험법 [Enforcement Date 27. Jan, 2010] [Act No.9988, 27. Jan, 2010, Partial Amendment]