In order to provide quality and safety of liquid cargo carried by sea, it is necessary to obey the rules of its protection. During maritime transport edible oils are prone to detrimental influence of many external factors such as supply of oxygen, of water, of metal ions and of pollution, as well as changes of temperature and mixing caused by ship movement. Due to them, they could undergo oxidation reactions, hydrolysis, polymerization and various types of physical transformation. On account of them the deterioration of nutritional, health and sensory qualities of fat could occur. The aim of the study was the assessment of the dynamic of changes with oxidative character (peroxide value and TBA index) which could appear in edible oils depending on their storage conditions. The analysis, which lasted 12 weeks, concerns rapeseed oil. Oxidative changes were registered every two week. The storage conditions in the atmospheric air induced danger connected with oxygen presence, whereas nitrogen blanketing eliminated this risk factor. The assessment also includes the influence of temperature of storage (indoor temperature 20˚C or refrigeration temperature 4˚C) and mixing of the fats. The results indicate that nitrogen blanketing, lowering the temperature and eliminating the mixing during storage of oil have highly positive impact on reduction of oxidative changes in fats.