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.
So exactly what temperature should a fridge be? Your fridge should be cooling food anywhere in between 36 and 40 degrees Fahrenheit (2.2 to 4.5 degrees Celsius). How do you test this? Use a probe thermometer to gauge the temperature of the inside of food that has been sitting in your fridge for at least 24 hours.