The Department of Homeland Security -
Science and Technology Division recently announced:
In a simulation of midday summer solstice sunlight at midlatitudes (max UVB), coronavirus half-life in saliva droplets on nonporous surfaces (e.g.: stainless steel) is 1 to 2 minutes.
Each minute of UVB in our Blu Room is roughly equal to 3 minutes of the midday summer solstice UVB at midlatitudes (45 degrees North).