Danger zone is between 4 and 60 degrees C.
Below 4 degrees (refrigerator is between 0 and 4), bacteria grow very slowly.
Above 60 degrees, (most) bacteria will be killed.
Below freezer temperatures (-18), bacteria stop multiplying.
That is why between 4 and 60, it is the danger zone for food safety.
By the way, please put an underscore where you expect an answer. Otherwise it looks like an incomplete sentence, like ".... for safety food is considered to be___________" Thank you.
