Santiago, August 4, 2026. Codelco decided to temporarily suspend development and construction activities at the Andes Norte project of the El Teniente Division, as a preventive measure aimed at safeguarding the safety of people.

This decision is based on technical analyses derived from data collected over the past six months, which recommend adopting this preventative measure while work continues to deepen our understanding of the deep seismicity of the deposit. These analyses have identified an emerging seismic phenomenon with characteristics distinct from the risks historically known and managed in the operation.

El Teniente has coexisted for decades with seismic phenomena associated with underground mining using the panel caving method. Both the seismicity linked to mining operations and that associated with the construction of mining developments are known risks, understood and managed through established operational controls.

However, the available background information is consistent with the potential existence of an emerging risk associated with the greater depth of the Andes Norte project works, the behavior of which continues to be investigated and analyzed. Among the elements considered are the need to strengthen instrumentation, monitoring, and technical analysis to address the challenges posed by the future development of deep mining.

Consequently, and prioritizing the protection of people, it was decided to temporarily suspend activities in that sector while the process of strengthening technical knowledge advances and the necessary control measures are determined and implemented to continue developing the project under the high safety standards that Codelco applies in all its operations.

In parallel, Codelco maintains operational seismic monitoring systems, safety protocols and preventive measures in all areas of the El Teniente Division, including production areas.

Relationship with contracting companies and their workers

The suspension of the Andes Norte project also affects the contracting companies involved in the development and construction activities.

The decision was immediately communicated to the companies involved and an orderly suspension of activities was initiated, taking into account the corresponding administrative, contractual and labor measures.

Codelco will maintain ongoing coordination with contracting companies to facilitate this process, ensure that its effects are managed responsibly, and guarantee strict compliance with labor legislation and applicable contractual obligations.

Codelco