123misha:o.

>>> snip

Sorry if the question is incomplete. What I was asking about UV was if used as a sterilizer or I will use it to sterilized my phone or keys is it effective?


Thank you for your reply.

 

The correct wavelength of UV  could be very effective. To kill germs you need UV-C, ( 100–280 nm wavelength, and also the dangerous one to humans as well as to bacteria)

You would need however to arrange things so that all sides of the keys phone or what have you are exposed more or less equally, understand that any bugs in gaps and cracks that are shadowed from the direct light will not  get killed.

You must ensure that there are interlocks on the enclosure so that when the UV lights are on you cannot get any part of you near it. The dose for killing bacteria is quite a bit higher  than that which causes skin burns and eye damage.

A total dose of about 20millijoules per square cm at a wavelength of 260nm should do it in terms of killing most bacteria>99.9%. (The time/ intensity product can be traded, so a weak source for longer.) Longer and shorter wavelengths are slightly less effective.



Do not use this technique with plastics that bleach and disintegrate  in the sun - they will do the same  in the UV.


Some background reading
https://www.sciencedirect.com/science/article/pii/S0305417919300920#bbib0035

https://iuva.org/resources/covid-19/Woods et al 2015 - UV222 Pilot Study Testing on Volunteers Skin.pdf

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6801766/



 

123misha:o.

>>> snip

Sorry if the question is incomplete. What I was asking about UV was if used as a sterilizer or I will use it to sterilized my phone or keys is it effective?


Thank you for your reply.

 

The correct wavelength of UV  could be very effective. To kill germs you need UV-C, ( 100–280 nm wavelength, and also the dangerous one to humans as well as to bacteria)

You would need however to arrange things so that all sides of the keys phone or what have you are exposed more or less equally, understand that any bugs in gaps and cracks that are shadowed from the direct light will not  get killed.

You must ensure that there are interlocks on the enclosure so that when the UV lights are on you cannot get any part of you near it. The dose for killing bacteria is quite a bit higher  than that which causes skin burns and eye damage.

A total dose of about 20millijoules per square cm at a wavelength of 260nm should do it in terms of killing most bacteria>99.9%. (The time/ intensity product can be traded, so a weak source for longer.) Longer and shorter wavelengths are slightly less effective.



Do not use this technique with plastics that bleach and disintegrate  in the sun - they will do the same  in the UV.


Some background reading
https://www.sciencedirect.com/science/article/pii/S0305417919300920#bbib0035

https://iuva.org/resources/covid-19/Woods et al 2015 - UV222 Pilot Study Testing on Volunteers Skin.pdf

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6801766/