This regional guideline aims to give general recommendations and provide information needed for proper decision making when responding to accidents in the marine environment involving chemicals and dangerous goods. It shoud not, however, be taken as a substitute for the national guidelines and manuals on HNS spills response existing in NOWPAP member states. The guideline is based on existing regional (HELCOM, REMPEC and Bonn Agreement) and national (NOWPAP member states) manuals and recommendations. The contents of this guideline must be thoroughly reviewed beforehand and are primarily aimed for personnel who are familiar with the area.