Operational Safety and Spoil Management Protocol for Tunnel Excavation in Naturally Occurring Asbestos-Bearing Rocks: An Italian Experience

This technical note describes a protocol for the safe excavation of asbestos-bearing serpentinite and the management of the associated spoil during tunnel construction. Asbestos fibers occur naturally in serpentinites belonging to greenstone formations and may pose serious health risks if released and inhaled. Detailed, site-specific risk assessment is therefore required for tunnelling and earthworks involving these lithologies. Where excavation through greenstones cannot be avoided, as in the construction of major national and international infrastructure networks, dedicated safety and waste-management procedures are necessary to minimize occupational and environmental risks. The protocol was implemented considering Italy’s extensive experience with tunnel construction sites and integrates operational controls, environmental monitoring, personal protective equipment, and procedures for the characterization and management of rocks potentially containing asbestos. Drawing on practical site experience, it provides a structured framework for risk assessment, worker protection, exposure prevention, and appropriate spoil classification and handling. The proposed approach is also consistent with circular-economy principles, as more detailed material characterization can enable greater recovery of excavated material for reuse. The present technical note may therefore serve as a practical reference for comparable tunnelling projects involving naturally occurring asbestos.