Explosion while charging materials in a reactor 안전분야-교육자료 미디어개발 2009-98-477 Manufacture Serious Accidents in Manufacturing - 2009.05 Explosion while charging materials in a reactor (Inflammable – explosion) The copyright to this material belongs to the Korea Occupational Safety and Health Agency. Unauthorized use and distribution are prohibited. If an individual uses this for non-commercial purposes, the Korea Occupational Safety and Health Agency must be cited as the source. A corporation using this material must obtain permission from the Korea Occupational Safety and Health Agency first. Using this material without prior permission will be considered copyright infringement, and legal action may be taken.

I. Fatality Overview Table of Contents II. Process Overview III. Fatality Object IV. Fatality Process Power Point Training Material on Serious Accidents in Production V. Fatality Cause VI. Precautions

Fatality Overview Date & Time: 14:00, June O, OOOO I. Fatality Overview II. Process Overview III. Fatality Object IV. Fatality Process V. Fatality Cause VI. Precautions Fatality Overview Date & Time: 14:00, June O, OOOO Place: chemicals manufacturing workplace in Choocheongbuk-do Victim: a production worker While the victim was charging materials into a reactor, inflammable substance (allyl alcohol) of remained vapor in the reactor exploded by static electricity. He died of the burn. Power Point Training Material on Serious Accidents in Production Fatality Site

Process Overview Process Overview (plastic glass lens materials) I. Fatality Overview II. Process Overview III. Fatality Object IV. Fatality Process V. Fatality Cause VI. Precautions Process Overview Process Overview (plastic glass lens materials) Material Input 1st Reaction Decompression Pressurization 2nd Reaction Mixing Packing Shipping Fatality Process Fatality Process Materials DMT: Diethyl Terephthalate (solid flake state materials) DMI: Diethyl Isophthalate (solid flake state materials) Allyl Alcohol (liquefied materials) Other additives (catalyst, etc) Operation condition 1st Reaction: ambient pressure, maximum operating temperature was 120℃ (cool down to approx. 40 ℃ after discharging of reactant) 2nd Reaction: N2 Purge, maximum operating temperature was 170℃ Power Point Training Material on Serious Accidents in Production

Remaining DMT in reactor I. Fatality Overview II. Process Overview III. Fatality Object IV. Fatality Process V. Fatality Cause VI. Precautions Process Overview Process Overview - Materials inputting method - DMT, DMI: directly input into reactor with a 500kg bag using a crane - Allyl Alcohol: input using a pump and piping - Other additives: directly input into reactor manhole - Materials inputting order and amount - DMT 500kg x 2 bags - Catalyst and additives - DMT 500kg, DMI 500kg - Allyl Alcohol (approx. 2,400kg) - Start heating Remaining DMT in reactor Power Point Training Material on Serious Accidents in Production 5

III. Fatality Object Fatality Object: Allyl Alcohol I. Fatality Overview II. Process Overview III. Fatality Object IV. Fatality Process V. Fatality Cause VI. Precautions III. Fatality Object Fatality Object: Allyl Alcohol Vapor specific gravity: 2.0 (air: 1) Flash point: 21.5℃ The highest & lowest explosion limit: 2.5 (the lowest) ~ 18 (the highest) vol % Molecular formula: H2-C-C-H-C-H2-O-H Power Point Training Material on Serious Accidents in Production 6

I. Fatality Overview II. Process Overview III. Fatality Object IV. Fatality Process V. Fatality Cause VI. Precautions IV. Fatality Process The victim started his work at 16:00, June OO, OOOO Workers at each team were two workers in production department. victim and a co-worker was one team. working hours for the 2nd was 16:00 ~ 22:00. When the victim started his work, intermediates that completed the 1st reaction in reactor No. 1 was all discharged into reactor No. 2. Worker B, who belonged to the previous team, even after the shift, finished l manhole packing replacement owing to leakage at the second reactor manhole and went back to dormitory. The victim was still working until the co-worker went back to the dormitory. Reactor No. 1 was about 40℃ during materials input. Therefore, even though the semi-finished products were charged after completing the reaction, there was still excessive input of Allyl Alcohol vapor in the vessel. Power Point Training Material on Serious Accidents in Production 7

I. Fatality Overview II. Process Overview III. Fatality Object IV. Fatality Process V. Fatality Cause VI. Precautions IV. Fatality Process After completing reaction, they ejected all semi-manufactured products, closed manhole, and make vacuum in the reactor using a vacuum pump (remaining vapor ventilation). However, the vacuum degree was usually about 400mmHg and perfect ventilation or replacement in the vessel was not possible. When the victim was inputting a large amount of DMT, static electricity occurred in the reactor causing an explosion. The victim who was working at the side of the reactor got 3-degree burned on the whole body to death. Power Point Training Material on Serious Accidents in Production 8

V. Fatality Cause No protections against static electricity I. Fatality Overview II. Process Overview III. Fatality Object IV. Fatality Process V. Fatality Cause VI. Precautions V. Fatality Cause No protections against static electricity A large amount of DMT with possibility of static electricity inside the reactor owing to remaining inflammable vapor was charged into the reactor using a crane. There were no protections against static electricity prior to work. Insufficient inside ventilation - To input materials in the reactor with possibility of static electricity hazard, you must thoroughly eliminate inflammable vapor inside the reactor. However, inside ventilation was not sufficient. Power Point Training Material on Serious Accidents in Production 9

VI. Precautions Improving materials inputting method I. Fatality Overview II. Process Overview III. Fatality Object IV. Fatality Process V. Fatality Cause VI. Precautions VI. Precautions Improving materials inputting method To minimize occurrence of static electricity, you must prepare protections against static electricity such as installing metal hopper and chute to input regular amount of granular materials to eliminate any possibility of static electricity. Thorough inside ventilation - Since there is a limit of inside ventilation using a vacuum pump, it is recommended that separate ventilation device be installed. For perfect and thorough ventilation, it is necessary to connect a ventilation hole down to reactor bottom and replace inner air using inert gas such as nitrogen prior to any work. Power Point Training Material on Serious Accidents in Production 10

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