These symptoms pass quickly and there seem to be no long term effects of high tin exposure. However, repackaging food once a can is opened is a good practice to adopt for all foods packaged in metal cans. Throw out the contents of any can which has an unusual colour, or odour. Do not taste. However, if the temperature of frozen food is allowed to rise for any length of time a series of changes such as the growth of microbes, chemical reactions and physical changes can occur.
Many frozen foods contain fat which can become rancid during storage.
The higher the temperature and the fattier the food, the faster rancidity will develop. Cooked meats and meats containing high levels of salt, such as cured meats, tend to go rancid more quickly and have a shorter storage life. At higher storage temperatures some vitamins may also be lost. The growth of ice crystals is another detrimental change which occur during frozen storage. Large ice crystals cause damage to food by changing its texture and resulting in greater loss of liquid on thawing.