The Japan Association for the 2025 World Exposition (hereinafter referred to as “the Association”) is continuously measuring methane gas concentrations across the Expo site and regularly publishing the results in an easy to understand manner as part of our efforts to provide information to visitors and others.
On 2 June 2025, we announced the methane gas concentration results for the first month after the opening of the Expo. We have now compiled the methane gas concentration results for the period of 13 May 2025 to 12 June 2025.
The measurement results are summarised below:
・ No methane gas levels equal to or above the standard value were detected inside buildings or around paths.
・ No methane gas levels equal to or above the standard value were detected in the underground pits for outdoor equipment. In addition, nine pits, including two where concentration above the standard value were detected between 13 April and 12 May, were replaced with grating covers.
Note: The “standard value” is 1.5 vol% as stipulated in the Ordinance on Industrial Safety and Health. The lower explosion limit of methane gas is 5 vol%.
・ Methane Gas Concentration Measurements at the Expo Site (13 May – 12 June 2025)
・ Response to methane gas in underground pits for outdoor facilities (as of 12 June 2025)