germicidal

Use of UV lamps as a germicidal goes back to the 1930's, so killing organisms with UV isn't new.

Doubling down on your comment about germicidal UV.

Equally, sunlight is germicidal and there is now evidence it can kill the flu virus.

The existing standard way to get germicidal UV is low pressure mercury lamps.

The bog-standard germicidal lights emit UV at 254 nm, but to generate ozone you'd need vacuum UV at 189 nm.

Anything in that range will have a germicidal effect, but this happens to be a cheap and effective way of generating UV.

Isn't buying silver plated better due to germicidal properties of silver?

Do you have information on how common materials such as plastics and clothing fabrics respond to a germicidal level of UVC?

Essential oils in concentrations that are germicidal are definitely not safe around people for prolonged exposure.

[Aside, I believe the peak germicidal wavelength is 265nm, 253 is just the nearest line that mercury lamps have].Some of the applications you mention might be problematic because many indoor materials aren't particularly UV durable.

Here we extended our previous studies to 222-nm light and tested the hypothesis that there exists a narrow wavelength window in the far-UVC region, from around 200–222 nm, which is significantly harmful to bacteria, but without damaging cells in tissues.> As predicted by biophysical considerations and in agreement with our previous findings, far-UVC light in the range of 200–222 nm kills bacteria efficiently regardless of their drug-resistant proficiency, but without the skin damaging effects associated with conventional germicidal UV exposure.