Copper sulfate, a naturally occurring and manufactured copper salt, is used as a fungicide on crops, as a pesticide to kill snails and slugs, and as water treatment to kill aquatic vegetation. This chemical has serious chronic toxicity with implications for agricultural workers and the environment.
1 Keep the refrigerator temperature at or below 40Â° F (4Â° C). 2  The freezer temperature should be 0Â° F (-18Â° C). 3  Check temperatures periodically. 4  Appliance thermometers are the best way of knowing these temperatures and are generally inexpensive.
In order to keep food out of the Danger Zone, your fridge must be set between 32-40Â° F (0-4 degrees Celsius). Your freezer must be below 32Â° F (0Â° Celsius). I keep mine as cold as it will go.