Dr Lowe explicitly mentions the danger of 254 nm: > That's very much as opposed to (say) 254 nm light, which starts doing damage immediately due to greater pen

Dr Lowe explicitly mentions the danger of 254 nm: > That's very much as opposed to (say) 254 nm light, which starts doing damage immediately due to greater penetration into animal tissue. and that 200-222 is safer because of lower penetration. > down in that range, the penetration of such light is only a few microns, and it doesn't even get past the dead cells on the surface of the skin and the cornea of the eye!