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What is the proper temperature for your refrigerator?

Refrigerators should maintain a temperature of 5°C or less, which is important because it slows the growth of most bacteria. The temperature won't kill the bacteria, but it will keep them from multiplying, and the fewer there are, the less likely you are to get sick from them. Listeria monocytogenes may still grow slowly at these temperatures; this is the reason for not keeping foods too long in the fridge. Clean the fridge regularly (with hot water and a disinfectant) to remove and kill Listeria bacteria that grow in food residues present in the fridge.

Freezing at minus 18 °C or less stops bacterial growth (although it won't kill all bacteria already present).

Based on : http://iastatefoodservice.custhelp.com