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 temperature for a refrigerator is between 34 and 40 degrees Fahrenheit, and the ideal temperature for a freezer is at least 0 degrees Fahrenheit. Although this temperature keeps food safe in a freezer, food quality sometimes benefits when the freezer is lowered to -10 or -20 degrees Fahrenheit.