7.2 Module B1 – Use. Written by Anh-Migrate on 21. October 2012. Posted in Existing buildings, New buildings. 7.2 Module B1 – Use. B-01 Emissions of dangerous substances to indoor air during the use stage. B-02 Release of dangerous substances to soil and water during the use stage. Lifecycle stage: B (all modules), Lifecycle stage: B1 Previous Next