"Normal" refrigerator temps

The recommended temperatures for refrigeration by the FDA or other enforcing agencies will be the maximum temperature and not necessarily the ideal nor sought after temp. Pathogenic bacteria will proliferate at temperatures between >40-<140 deg F so at temperatures above or below these two temps will prevent the growth of these bacteria. Not all bacteria are bad and the important ones, the pathogenic ones live in this range. So I feel that at a temperature as low as you can get without freezing foods is the ideal point to look for. Of course not all foods freeze at the same temperature so keep in mind the more susceptible one to low temperature like vegetables.