The authors examine the threats from hazardous toxic materials from World War II wrecks sunk in the Baltic Sea and their cargo of chemical ammunition, indicate Poland’s reaction to this situation, and map out Polish obligations in this regard. This problem gives rise to multiple uncertainties about the exact nature of threats to environmental/ecological security, marine security, human security (including health security), economic security and food safety. The authors also elaborate on legal regulations relevant in this context. The research methods include formal-institutional analysis of relevant legal documents and discourse analysis. The main conclusions are: 1. toxic materials in the Baltic Sea threaten ecological, economic, human and security; 2. food safety in all Baltic states might be endangered; Poland should accede to the Nairobi Wreck Removal Convention; and Poland should cooperate regionally to resolve the problem of the Baltic chemical waste.