Desiccators are chemicals or apparatuses that remove moisture from a substance. The first type is common in the consumer industry and generally takes the form of small packets of silica that often are found in certain types of packaging for foods such as beef jerky as well as vitamins and food supplements that come in tablet form. They also sometimes are found in packaging for clothing or shoes. There also are machines used in laboratory and industrial applications that are also known as desiccators and that essentially perform the same function, but they might work in an active way or in the passive way that silica packets work.
Little white packets of silica often are used in various types of consumer packaging to absorb moisture in the air in sealed packages of foods. These desiccators help keep foods fresher by keeping the air in the packaging as dry as possible. Foods such as beef jerky and freeze-dried foods often have a little packet of this material included in order to extend shelf life.
They also are sometimes found in clothing packages and shoe boxes, because excessive moisture can cause mold or fungal growth on these consumer goods. Electronics also commonly have these packets included as a way to keep their sensitive components as moisture-free as possible. Iron oxide is another common ingredient in desiccators.
Many people mistakenly believe silica to be poisonous. Silica actually is a mineral, silicon dioxide, and is a common component of many rocks and soils. It is one of the main components of sand. Silica itself is inert, but ingesting it can be dangerous because it can cause gastric distress and intestinal blockages. The silica found in the packets of desiccators also might be coated with a potentially carcinogenic chemical called cobalt chloride that is used as a moisture indicator, and ingesting this would be ill-advised at best.
There also are machines called desiccators that serve essentially the same function, but they use mechanical means, often by use of a vacuum, to remove moisture from things put inside them. These machines are common in laboratories and in industrial applications where it is desirable to dry the object or product without heating it. They are commonly used for making dried or powdered food products such as powdered milk, dried fruit and many other foods.
These machines may be very large. They are common in laboratories and often are used in experiments when the scientist or technician wishes to dry something quickly without heating it. They also are used to store materials that react with water or are damaged by moisture.
These units often are countertop apparatuses, but larger machines of this type also are common. Laboratory dessicators often simply are sealed, heavy glass storage containers with a compartment that contains a desiccant such as silica that absorbs any moisture. They also might be designed to have the air inside the container evacuated, and these types are called vacuum desiccators.