The article reviews of the state of investigations concerning the threat of chemical warfare agents (CWA) dumped in the Baltic Sea to the health of people making use of the sea. The paper presents the types and quantities of chemical munitions dumped in the Polish sector of the Baltic Sea, the location of dumping sites and localities where accidental injuries to people have taken place. The results of the HELCOM ad hoc Working Group on Dumped War Gas and Ammunition in the Polish Economic Zone are also reviewed. The approximate condition of the dumped CWA and their status on the sea floor are discussed. The Polish studies on the deactivation of CWA are summarised.