Regarding the Resumption of Production at Omuta Works

Mitsui Chemicals, Inc.(Tokyo:4183; President &CEO: HASHIMOTO Osamu) deeply apologize to those who felt unwell due to the gas leak that occurred on the evening of July 27 at our Omuta Works, as well as to their families, nearby residents, related authorities, customers, and many others for the great concern and inconvenience caused by this incident ( "the Incident").

We would like to inform you that with the resumption of production of the TDI manufacturing facility, which had been halted due to the Incident, on September 11, production of the lens monomer, which had also been partially suspended, has resumed from September 14. The production facilities of TDI and lens monomer are operating stably, and we will continue to make every effort to ensure safety as well as to maintain the supply chain.

We solemnly acknowledge the seriousness of the Incident and, not only at our Omuta Works but across the entire company as one, we will revisit our basic principle of prioritizing safety and thoroughly reinforce safety management once again. We will also devote all our efforts to implementing recurrence prevention measures and further raising safety awareness among all employees, striving to strengthen disaster prevention.