Hydraulic fracturing is a technique that has been applied for stimulation of conventional oil and gas wells in the US since many years. The recent developments in high volume hydraulic fracturing combined with directional/horizontal drilling techniques have made the gas trapped into unconventional reservoirs such as shale formations economically exploitable. In the US, shale gas has become an important energy resource. In the EU, there is limited experience in the use of these techniques and research/experimental drilling activities have been performed in some Member States where shale gas reservoirs are present. In this context, the EC's Joint Research Centre’s Institute for Health and Consumer Protection (JRC-IHCP) was asked by EC's DG Environment to perform an assessment of REACH registration dossiers of certain selected substances that may be connected with the use in hydraulic fracturing of shale gas reservoirs. The main goal of this task was to understand whether this type of use has been registered under REACH and eventually how industry is dealing with related exposure scenarios and exposure assessments. The present document reports and discusses the results of the analysis of the selected REACH registration dossiers. ; JRC.I.4-Nanobiosciences