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CBW Corner

CBW Corner

Providing a resource for arms control treaty implementers to assist them with keeping
up-to-date on the issues and events critical to understanding and eliminating chemical and biological weapons.



  • Japanese scientists began to develop chemical weapons in 1917. By World War II, the Japanese Imperial Army had a chemical weapons arsenal of five to seven million munitions, containing phosgene, mustard, lewisite, hydrogen cyanide, and diphenyl cyanarsine. [Japan color-coded its chemical weapons shells. Click here to find out more.] China claims that Japan used chemical weapons 2,900 times during World War II, killing both Chinese soldiers and civilians. The latest casualty of Japanese WWII-era chemical shells died in August 2003. A stone monument established in April 1954. It reads "Chemical Weapons Abandoned by Japan."Photo credit: Prof. Kei-ichi Tsuneishi (Kanagawa Univ.), 1994

  • After its surrender to Allied forces in June 1945, Japan abandoned its remaining chemical weapons, estimated by some historians as millions of shells and dozens of tons of gas, and pledged not to produce CW. At the Conference on Disarmament in 1992, China issued a paper presenting the details of some two million Japanese abandoned chemical munitions and another 300,000 CW destroyed or preliminarily treated munitions on Chinese territory. It was estimated that the two million munitions totaled 100 tons and the destroyed munitions at another 20 tons. It wasn't until 1999, two years after the entry into force of the Chemical Weapons Convention, that Japan signed an agreement to destroy its abandoned chemical weapons (ACW) in China in accordance with its obligations under the CWC.

  • Removal and disposal of chemical munitions began with 500 shells abandoned in Beian, Heilongjiang Province, but approximately 90 percent of the Japanese ACW is located near Dunhua, Jilin Province. ACW were also found in Shanxi, Hebei, Enhui, Zhejiang, Jiangxi and Jiangsu Provinces as well as the Autonomous Region of Inner Mongolia. A 1999 estimate of the ACW unearthed concluded that 18 percent still contained explosives and 53 percent still contained agent. Japan' s best estimate, based upon the figure of 700,000 shells and not the Chinese estimate, for completion of removal and disposal of the ACW places the complete date far past the 2007 deadline mandated by the CWC, however and extension can only be granted at China's consent.

  • While not the first incident, the most recent chemical weapon death in China serves as a reminder of the danger posed by ACW. In late August 2003, 36 workers in Heilongjiang Province were exposed to mustard gas when they discovered five barrels at their construction site. One of the barrels ruptured while being extracted and leaked on the ground. Unaware of its contents, the workers cut down the barrels and sold them to a recycling company and also removed the dirt to another site. Later, all 36 workers became ill with symptoms consistent with mustard gas exposure and one of the workers died.

  • China is seeking compensation for the mustard gas victims. While Japan has acknowledged responsibility for the ACW, Chinese victims from the Japanese ACW often have difficulties in securing compensation for their injuries from the Japanese government. In May 2003, a Tokyo court ruled against five Chinese nationals who had filed suit against the Japanese government claiming that they had suffered blistered skin and breathing difficulties after inhaling poison gas from canisters abandoned by the Imperial Japanese Army. While rejecting their claim to compensation, presiding Judge Takashi Saito acknowledged that the plaintiffs had, indeed, been harmed by the ACW. However, Saito ruled that: "The Japanese government cannot take effective steps to prevent Chinese from falling victim to the poison gas because even if Tokyo asked Beijing to recover and store the chemical weapons, the request would be affected by China's decision." Japanese citizens injured by WWII-era CW and its contamination on Japanese soil have had little difficulty in obtaining compensation for their injuries from the Japanese government.

  • The problems posed by Japan's ACW highlights an important treaty issue: how does the CWC address State Party obligations to destroy or eliminate ACW? The issue of ACW is addressed in the Verification Annex of the CWC, Part IV(B). As the State Party on whose territory CW were abandoned, China is the Territorial State Party (TSP) under the CWC. As the State Party who abandoned CW on another State Party's territory after 1925, Japan is the Abandoning State Party (ASP). In the case of ACW in China, Japan as the ASP is obligated to destroy the CW it abandoned on Chinese territory by April 2007. An extension could be granted with the approval of both the OPCW Executive Council and the TSP. The TSP is required to cooperate with the ASP to facilitate the removal of the ACW, and the ASP undertakes both the technical and financial responsibilities for the safe removal and disposal of the chemical weapons and agents. If the ASP is not a State Party or can not be identified, then the TSP could request OPCW assistance in the destruction of the ACW.

  • Japanese and Chinese weapons experts prepare to examine poison gas shells in a pit at Luquan in northern China's Hebei province Friday Sept. 12, 2003. (AP Photo/Nicky de Blois)

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