Material event report (treasury share acquisition) (subsidiary)

What happened

Material Event Report / Exchange Reporting Obligation - Material Management Matter Report of Subsidiary Dongnam Chemical Co., Ltd.

To the Financial Services Commission / Korea Exchange July 8, 2026 Company name: Dongnam Chemical Co., Ltd. CEO: Park Mi-ryeong Head office: 80-61 Tancheon Sandan-gil, Tancheon-myeon, Gongju-si, Chungcheongnam-do Phone: 041-840-3100; Website: http://www.dongnamchem.com Preparer: Title Division Head, Name Seo Won-cheol, Phone 031-472-7619

Decision on Treasury Share Acquisition

1. Shares planned for acquisition: Common shares 25,000; Other shares - 2. Planned acquisition amount (KRW): Common shares 697,500,000; Other shares - 3. Expected acquisition period: start July 9, 2026; end October 8, 2026 4. Expected holding period: start -; end - 5. Purpose of acquisition: Share price stabilization 6. Method of acquisition: Purchase through the KOSPI Market 7. Entrusted brokerage firm: NH Investment & Securities 8. Treasury shares held before acquisition: within distributable profit range - Common shares 170,780 (4.9%); Other shares - (-); other acquisition - Common shares - (-); Other shares - (-) 9. Date of acquisition decision: July 8, 2026; Outside directors' attendance: 2 attended, - absent; Attendance of auditor (non-outside-director audit committee member): Attended 10. Daily purchase order quantity limit: Common shares 2,500; Other shares - 11. Other matters for investors' reference 1) The planned acquisition amount is based on the closing price on the business day before the preparation date, and the actual acquisition quantity may change depending on future share price movements. 2) Daily purchase order quantity limit and basis of calculation - Daily purchase order quantity limit: 2,500 shares - Basis (the limit is the smaller of C and whichever of A or B is larger): A. 10% of the reported acquisition share count = 2,500 shares; B. 25% of the average daily trading volume over the past month = 558 shares; C. 1% of total issued shares = 35,000 shares

Treasury Share Acquisition Amount Limit 1. Distributable profit limit under the Commercial Act as of the end of the preceding fiscal year a. Net assets: 54,536,610,423 b. Capital stock: 3,125,564,000 c. Sum of capital reserve and earned surplus reserve accumulated through the preceding fiscal year: 4,815,827,832 d. Unrealized profit as prescribed by presidential decree: - Subtotal (a-b-c-d): 46,595,218,591 2. Treasury share acquisition amount since the end of the preceding fiscal year: 1,143,742,430 3. Dividend amount resolved at the ordinary general meeting since the end of the preceding fiscal year, and related earned surplus reserve: 1,758,599,850 4. Quarterly/interim dividend amount resolved by the board since the end of the preceding fiscal year, and related earned surplus reserve: 2,163,993,000 5. Trust contract amount: - 6. Acquisition cost of shares disposed of since the end of the preceding fiscal year, if any (moving-average method): - Treasury share acquisition amount limit (1-2-3-4-5+6): 41,528,883,311

Treasury Shares Held Before This Acquisition Decision (Unit: shares) - acquisition method / type / beginning qty / acquired(+) / disposed(-) / retired(-) / ending qty: Direct acquisition, on-market: Common shares; beginning 134,000; acquired +36,780; ending 170,780. Other shares: all -. Direct acquisition, off-market: Common and other shares: all -. Tender offer: Common and other shares: all -. Subtotal (direct acquisition): Common shares; beginning 134,000; acquired +36,780; ending 170,780. Other shares: all -. Trust-contract acquisition (trustee-held and in-kind): Common and other shares: all -. Other acquisition: Common and other shares: all -. Total: Common shares; beginning 134,000; acquired +36,780; ending 170,780. Other shares: all -.