This CEN Technical Report describes a procedure for assessing construction products with regards to their release/emission of regulated dangerous substances (RDS) into the environment in accordance with Essential Requirement Number 3 of the Construction Products Directive (CPD), as far as these construction products fall under the responsibility of CEN. NOTE 1 For the purpose of this document and mandate M/366, the release of regulated dangerous substances from construction products is limited to two main environmental compartments: 1) soil, groundwater and surface water; 2) indoor air. NOTE 2 It should be noted that construction products falling under the CPD and these environmental compartments are the subject of other European Union regulations, e.g. REACH, and they may also be the subject of Member State regulations. This Technical Report defines how the mandated characteristics expressed in terms of mandated RDSs for each construction product can be assessed by an individual manufacturer using the ‘Without Testing’ (WT) procedure and/or the ‘Without Further Testing’ (WFT) and ‘Further Testing’ (FT) procedures after an initial type assessment and how the corresponding information accompanying the CE marking can be expressed in terms of declared values or RDS classes.