Negative ions, also known as anions, are atoms or molecules that have gained additional electrons. This creates an excess of electrons, which leads to a negative charge. They are widespread in nature and occur in higher concentrations in clean, natural environments such as mountains, forests and waterfalls.

The way negative ions work is diverse. They can capture and neutralize contaminated particles from the air. Negative ions bind and neutralize positive ions, which are often found in polluted environments and generated by various devices such as air conditioners, photocopiers and electronic screens.