This report is a review of the existing literature which determine the current level of knowledge of the benefits and costs associated with ⁠REACH⁠. The main focus of the review was on the identification of the gaps in the assessment of benefits. The current state of knowledge and any gaps in the benefit and cost data/information were broken down by each single component of REACH regulation, namely Registration, Information in the Supply Chain, Evaluation, Authorisation, Restriction, Guidance, Inspection and Enforcement. The results of the literature review have been used as a basis for proposing potential solutions for addressing the key data gaps.