April 16, 2025

Japanese Communist Party member of the House of Councilors Yamashita Yoshiki, raising the issue of the frequent detection of methane gas at the Expo 2025 site (Yumeshima Island, Osaka City), on April 15 urged the national government to instruct the Expo association to thoroughly implement safety measures.

Mogi Tadashi, acting secretary general of the Cabinet Secretariat Headquarters for the World Expo 2025, responded, “We will instruct the Japan Association for the 2025 World Exposition to take all possible measures, including those for on-site security guards and staff.”

In March of last year, a methane gas explosion occurred in the pavilion area at the center of the Expo site. During “test run” rehearsals (April 4-6), a fire broke out inside a pavilion which is still under construction, and methane gas exceeding the permissible limit in concentration was again detected in the area where the explosion had occurred.

The JCP lawmaker at a meeting of the Upper House Committee on Environment suggested that ventilation equipment and constant monitoring devices to measure methane gas concentrations be installed in all underground pits. He also suggested that trained staff with sufficient knowledge of methane gas be positioned throughout the Expo venue.

Mogi said in reply, “I will convey your suggestions to the Expo association and have it consider them.”

Past related articles:
> Explosible concentration of gas detected during Expo 2025 rehearsal [April 7, 2025]
> Flammable gas detected at Osaka Expo construction site [May 31, 2024]