July 21, 2023 / All Stories, Company News, Featured, Investors, Mercer Celgar Mercer International Inc. announces temporary curtailment of its Celgar pulp mill NEW YORK, NY, July 21, 2023 Mercer International Inc. (“Mercer” or the “Company”) (Nasdaq: MERC) today announced the temporary curtailment of operations at its Celgar pulp mill located in Castlegar, BC, including wood acceptance. The curtailment is currently scheduled to become effective July 29, 2023, until August 28, 2023. This temporary curtailment results from a significant loss of rail transport capacity resulting from the Vancouver port job action. The job action has led to a complete halt in railcar circulation, severely impacting the mill’s ability to transport pulp. President and CEO, Juan Carlos Bueno, expressed, “Regrettably, we are not able to run the mill economically until rail operations resume regular services. We currently expect the curtailment to persist for about a month. We understand the inconvenience and difficulties this may cause our various partners and stakeholders, and we will strive to keep all affected parties informed of any updates as the situation develops.” Mr. Bueno continued, “We truly appreciate the understanding and support of our employees, contractors, customers, suppliers, and communities during this challenging period and are diligently seeking alternative solutions to minimize any further disruptions.” About Mercer Mercer International Inc. is a global forest products company with operations in Germany, the USA and Canada with an annual production capacity of 2.3 million tonnes of pulp, 960 million board feet of lumber, 210 thousand cubic meters of cross-laminated timber, 45 thousand cubic meters of glulam, 17 million pallets and 150,000 metric tonnes of wood pellets. For further information, please visit www.mercerint.com. The preceding includes forward-looking statements which involve known and unknown risks and uncertainties, including regarding the expected duration of expected downtime at our mill, which may cause our actual results in future periods to differ materially from forecasted results. Words such as “expects,” “anticipates,” “projects,” “intends,” “designed,” “will,” “believes,” “estimates,” “may,” “could” and variations of such words and similar expressions are intended to identify such forward-looking statements. Among those factors which could cause actual results to differ materially are the following: the highly cyclical nature of our business, raw material costs and availability, our level of indebtedness, competition, foreign exchange and interest rate fluctuations, our use of derivatives, expenditures for capital projects, environmental regulation and compliance, disruptions to our production, market conditions and other risk factors listed from time to time in our SEC reports. APPROVED BY: Jimmy S.H. Lee Executive Chairman Juan Carlos Bueno Chief Executive Officer Contact: For further information and updates, please visit www.mercerint.com or contact Richard Short, Chief Financial Officer & Executive Vice President, at (604) 616-3192.