Introduction Failure to comply with company procedures regarding entry into enclosed spaces can be fatal. This key shipboard operation sadly continues to cause injury and take lives every year, and in the following we briefly deal with the hazards, regulations and procedures involved in entering enclosed spaces. The most frequent hazards when entering an enclosed space are the following: Oxygen depletion or enrichment Carbon monoxide exposure Hydrogen sulfide exposure Toxic atmospheres Flammable atmosphere Enclosed space means a space which has any of the following characteristics: Limited openings for entry and exit; Inadequate ventilation; and Is not designed for continuous occupancy. Regulations The International Convention for the Safety of Life at Sea (SOLAS), 1974 caters for, and regulates, the risk associated with entering enclosed spaces. The shipping company must provide a Safety Management System (SMS) which takes into consideration the SOLAS requirements and supports the crew with instructions, procedures and checklists for them to mitigate known risks associated with such entries. The SMS should be tailored to the respective vessel and be designed as an intuitive system supporting the crew to perform their onboard duties in a safe manner. Procedures and precautions Investigations show that accidents, in most cases, are caused by insufficient knowledge of the need to take precautions when entering enclosed spaces. Crew directly or indirectly engaged in entering enclosed spaces must accordingly be familiarized with the company Safety Management System (SMS) mentioned above. Skuld would like to emphasize and highlight the importance for ship managers to assess the key aspects of enclosed space entry operations, including, but not limited to, the following: Risk assessment Roles and responsibility Communication Ventilation Testing of atmosphere Authorisation for entry Continuous testing Also, in accordance with IMO resolution A. 1050 (27) supplied from