Fresh 'N Cold panels contain odorless, all-natural, non-toxic, biodegradable and environmentally safe volcanic mineral (Zeolite) containing an electrical charge that acts as a magnet, attracting, trapping and holding unpleasant airborne odors.   

When placed inside a refrigerator or freezer it reduces the humidity, cleans the air of odors, and act as a temperature buffer.

How does Fresh 'N Cold reduce humidity inside a refrigerator and save energy?

When the door of a refrigerator containing Fresh 'N Cold is opened, the heat and water vapor (H2O) that are introduced into the refrigerator's atmosphere are swiftly absorbed by the volcanic crystals. This absorbing process prevents the moisture build up in the refrigerator and the formation of ice on the condenser coils. This process allows heat exchange to take place more efficiently, thereby requiring less energy consumption.
Why does Fresh 'N Cold buffer the temperature inside a refrigerator?

Water is a unique substance. Each molecule is polarized and positively charged (H) hydrogen portion of the molecule bonds weakly to the negatively charged (O) oxygen end of another water molecule. Because of the formation of these hydrogen bonds, water  (H2O) has a very high specific heat and is actually able to absorb heat before turning to vapor.
Inside the micro-channels of the  Fresh 'N Cold panels, water molecules are weakly bonded to both the framework of this unique mineral and other water  (H2O) molecules. When warm air is introduced to the inside of the refrigerator through the process of opening and closing of the door, the water  (H2O) inside of Fresh 'N Cold panels absorbs that heat by using the heat energy to break apart the (H) hydrogen bonds between water  (H2O) molecules. This heat exchange takes places inside the mass of Fresh 'N Cold panels unique mineral. Consequently, the air inside the refrigerator does not increase in temperature.
Bacteria, the leading cause of offensive odor and food spoilage, along with other microscopic and dust particles are carried into and around the inside of the refrigerator by and on water vapor  (H2O) molecules. These odor particles contain a positive (+) IONIC charge. The unique blend of minerals in Fresh 'N Cold have a negative (-) IONIC charge.
The gaseous water  (H2O) molecules are naturally attracted to the unique minerals because of their opposite charges, thus resulting in an occurrence called ADSORPTION, an electro-chemical phenomena. This process is different from that of a sponge which is a physical/mechanical action called ABSORPTION.
When the relative humidity inside the refrigerator is reduced below the optimum level for food storage, this unique mineral releases filtered water vapor  (H2O) molecules back into the air. This process is known as electro-chemical DESORPTION. During this DESORPTION process, the positively (+) charged particles of odor and bacteria are not released by the negatively (-) charged mineral, hence prevents food decay and excessive odor transformation.
The best part is that the volcanic crystals are renewable and work for up to 1 year.  We recommend that you take the panels out monthly and place them in the sun for several hours to recharge.  Please allow up to 8 hours for full effectiveness.