The ⁠REACH⁠ Regulation (EC 1907/2006) ensures chemical safety by requiring rigorous risk assessments before market entry. Safety data sheets (SDS) are vital for communicating safe usage guidelines, yet deficiencies are common, with up to 52% of SDSs found to be inadequate. This project aimed to identify gaps in SDS data by surveying actors across the supply chain with a specific focus on effect related to the environment. The key question driving the project was how far information on emission reduction measures is transferred by the registrants into their SDS and what is communicated along the supply chain. Using octamethylcyclotetrasiloxane (D4) as a case study, a substance with persistent, bioaccumulative, and toxic properties, the study assessed communication effectiveness. Despite a limited response rate, challenges in communication were identified, highlighting the need for improved coordination and transparency. Recommendations targeting both industry and regulatory agencies seek to enhance supply chain communication and address data gaps more effectively.