If your consent forms, materials transfer agreements or other data collection documentation did not contain clauses indicating that the data would or could be shared, it may not be ethical to share the data (depending on its sensitivity). In the case of human research participants, if it is possible to re-contact research participants to ask for consent for sharing, that would be optimal. However in many cases, it will not be possible to contact participants, or they may object to their data being shared. In this case, indicate in your Data Management Plan that the data was collected prior to the policy coming into effect.
