Zeolites are important materials for numerous industrial and consumer products. They have been used intensively for several decades. Zeolites are very porous, as their skeletal structure contains innumerable pores and channels ranging in size from nano to micrometers. Their structure resembles a sponge with many (micro or nano) holes, but they are not flexible. They belong to the very few material classes that are considered nanomaterials not only because they form nanoscale particles, but also because if they have nanopores. They are of particular interest as catalysts in chemical processes, as liquids can move freely through the pores and chemical reactions can take place on their walls. They can also be used for filtration: because of the nanopores, even very small substances can be separated, which is then called nanofiltration.
Further areas of application are for example: ion exchange, water softener in detergents, cat litter, fertilizer additive, self-cooling beer keg.
How could I get in touch with it?
By using zeolites as fertilizer additives, they could enter the food chain. Likewise, swallowing cannot be excluded if the water in swimming ponds is cleaned with the aid of zeolite powder. In addition, zeolite-based dietary supplements are offered time and again, although scientific proof of their effectiveness is lacking. Since it is also used as cat litter, in particular these animals repeatedly come into contact with zeolites, but also the people who clean the litter box.
How dangerous is the material for people and the environment?
Zeolites are poorly soluble in water, i.e. they are excreted unchanged when digested. However, no scientific studies have been conducted to date on the safety of the dietary supplements; these preparations are not approved as drugs in Germany.
So far there is no data available on how zeolites behave in the environment. Here it is generally difficult to differentiate naturally occurring zeolites from the technically produced zeolites. It is currently assumed that around 150 types of zeolite are produced industrially. Only some of them consist of nanoparticles. Since zeolites are used as phosphate substitutes in detergents, it cannot be excluded that the zeolites are released into the environment via the wastewater. Zeolites are converted into other compounds under natural conditions; in addition, zeolites also decompose in wastewater treatment plants. This decomposition releases components that contain aluminum and silicon. These components are also non-toxic.
Commercially available zeolites are not dangerous; they are excreted by the body.
By the way…
- Zeolites also have an antiseptic effect due to their mineral structure. This is particularly beneficial for animal health when using cat litter.