[en] A variety of materials are used during the construction process and the operation of the repository for spent nuclear fuel at Olkiluoto in Eurajoki, Finland. In addition to materials necessary for the construction and operation, some materials may be transported into the repository with the ventilation air, as emissions from vehicles etc. Both of these two types of materials are considered here and both introduced quantities and the quantities that remain after the closure in the repository are estimated here based on the most recent information. This work is intended to update the previous estimations, and it takes advantage of the experience collected during the construction of the underground rock characterisation facility called ONKALO at Olkiluoto. The implemented quantities as well as designs and preliminary designs have been used in calculating the quantities of the foreign materials. The estimations made in this report are specific to a KBS-3V type repository. In some cases more generic information has been used, particularly when the relevant quantities have not been monitored in ONKALO. The estimations are based on the new repository layout produced in 2010 and consider the latest plans for grouting and rock support. As all of these plans are not final some quantities may change in the future. As the repository layout may still go through some changes this report also provides the foreign materials for a hundred meters of different deposition tunnels designed for the OL and LO type canisters1. The results have also been calculated for a space demanded by a deposition tunnel end plug and the tunnel lengths before and after one. The most significant foreign materials are certain accessory minerals of the clay materials followed by organic materials (including the organic carbon from the clay materials), cement, steel and silica. (orig.)