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.
The ideal refrigerator temperature is 35Â°F (1.6Â°C). You're not hugging the danger zone like you would be at 40Â°F (4.4Â°C), and you're distancing yourself sufficiently from 32Â°F (0Â°C) that you don't freeze half the stuff in your refrigerator.