【Formosa Plastics】Announcement of Consolidated Revenue for May 2026

1.Date of occurrence: June 8, 2026 (115/06/08) 2.Company name: Formosa Plastics Corporation 3.Relationship with the company (please enter the company or subsidiary): The company 4.Mutual shareholding ratio: Not applicable 5.Reason for occurrence: Announcement of consolidated revenue for May 2026 6.Countermeasures: None 7.Other matters to be stated (if the subject of the event or resolution is a publicly issued company or above, this material information also meets the requirements of Article 7, Paragraph 9 of the Securities and Exchange Act Enforcement Rules, which has a material impact on shareholders' equity or securities prices): I. Comparison of consolidated revenue for May 2026 with April 2026: Consolidated revenue for May 2026 was NT$14,951.42 million, a decrease of NT$3,374.85 million or 18.4% compared to April 2026. The main reason was a decrease in sales volume, as explained below: Due to CPC Corporation and Formosa Petrochemical Corporation offering discounted supply of ethylene and propylene raw materials in May, the operating rates of the company's products decreased, and downstream customers were unable to pass on high costs, leading to more conservative purchasing and reduced production and sales volumes. Therefore, the combined sales volume of the company's major products in May 2026 decreased by 85,000 metric tons compared to April 2026. II. Comparison of consolidated revenue for May 2026 with May 2025: Consolidated revenue for May 2026 was NT$14,951.42 million, an increase of NT$99.39 million or 0.7% compared to May 2025. The reasons are explained below: 1. Increase in sales price variance of NT$4.4 billion: The outbreak of the US-Iraq war caused a surge in prices of crude oil, naphtha, and raw materials ethylene and propylene, pushing up petrochemical product prices. Therefore, the average prices of the company's major products in May 2026 increased by 33% to 68% compared to the same period last year. 2. Decrease in sales volume variance of NT$4.3 billion: The US-Iraq war led to the interruption of crude oil and naphtha supply from the Middle East, and the discounted supply of ethylene and propylene from CPC Corporation and Formosa Petrochemical Corporation this year led the company to reduce operating rates for various products, resulting in lower production and sales volumes. Therefore, the combined sales volume of the company's major products in May 2026 decreased by 129,000 metric tons compared to the same period last year.