“Plasma” is an ionized gas – the so-called fourth state of matter (the others being solid, liquid and gas) – and is generated by being energized up to 100,000 degrees or more. Natural examples for plasmas are the sun – a gigantic plasma ball – or lightning on Earth – temporary electrical discharges.
Cold atmospheric plasmas (CAP) are partially ionized gases, that means only one particle out of 1 ∙ 109 is ionized. The advantage of cold atmospheric plasmas is that they are “cold”, within the meaning that they operate under room temperature and can be produced at atmospheric pressure on Earth.
Generally, cold atmospheric plasma generates a reactive mix of electrons, ions, excited atoms and molecules, reactive species (e.g. O3, NO, NO2, etc.), UV radiation and heat. This mix inactivates bacteria, fungi, viruses, spores as well as odour molecules very efficiently.