###### Abstract  
The safety and effectiveness of plasma devices are of crucial importance for medical applications. This study presents the novel design of an atmospheric plasma torch (SteriPlas) and its characterisation. The SteriPlas was characterised to ascertain whether it is safe for application on human skin. The emission spectrum discharged from the SteriPlas was shown to be the same as the emission from the MicroPlaSter Beta. The UV emitted from the SteriPlas was measured, and the effective irradiance was calculated. The effective irradiance enabled the determination of the maximum UV exposure limits, which were shown to be over two hours: significantly longer than the current two-minute treatment time. The use of an extraction system with a higher flow rate appears to reduce slightly the effective irradiance at the treatment area. The NOx and ozone emissions were recorded for both SteriPlas configurations. The NOx levels were shown to be orders of magnitude lower than their safety limits. The ozone emissions were shown to be safe 25 mm from the SteriPlas cage. A discussion of how safety standards differ from one regulatory body to another is given.  
cold atmospheric plasma; biological and physical characterisation; plasma medicine; ultraviolet (UV); reactive oxygen nitrogen species (RONS); wound management; anti-bacterial; plasma healthcare; safety standards +
Footnote †: journal: Medical Applications  
0000-0002-2000-2000-2000-2000-2000-2000-2000-2000-2000-2000-2000-2000-2000-20000-2000-20000-2000-20000-20000-20000-20000-20000-20000-20000-20000-2000  
undertaken much faster as there is no requirement for a vacuum chamber [1]; surface engineering applications include nanometre etching of surfaces [2; 3; 4], deposition of nanometre coatings [5] and surface energy modification to improve the bonding of components [6].  
Atmospheric plasma generation has many other applications beyond surface engineering, which includes increasing the range planes can fly on a certain amount of fuel [7], increasing the energy efficiency of solar energy plants [8], nanomaterial processing [9], as surgical cutting tools [10], for cleaning of contaminated water supplies [11], and decontamination of microorganisms in medical applications [12].  
Clearly, many applications using plasma technology at atmospheric pressure now exist, and more are being invented every year. Considering that these technologies are being used in the open air and medical applications are being applied to humans, it is of paramount importance that these technologies are characterised and shown to be safe. Moreover, considering that these technologies will be deployed around the world, international safety standards must also be defined. [PERSON] et al. in 2016 published a DIN specification (German Standard) for characterising a mini plasma torch; however, the specification is only relevant in Europe; moreover, the method used to characterise the ultraviolet (UV) and ozone lacks transparency [13].  
The following work in this study shows the novel design of the plasma torch, an Adtec Healthcare SteriPlas, which is currently the largest CE-approved plasma device for human wound management, and its characterisation. The aim of this work is to show the key characterisation techniques that must be undertaken to demonstrate the safety and effectiveness of the medical plasma device. Furthermore, the UV and reactive oxygen nitrogen species (RONS) safety limits will be discussed in a global context, comparing how standards differ between different regions around the world. Finally, limits will be proposed for an international standard.