Is Sunlight the Best Disinfectant?

People often say, “Sunlight is the best disinfectant.” We put that to the test!  We exposed glass test surfaces inoculated with Staphylococcus aureus to midday sun at our laboratory for 5 and 10 minutes and compared reductions relative to surfaces shielded from the sun, but otherwise held under the same conditions.

 

Sunlight is not the best disinfectant, but it’s not bad either!  It killed about 99.9% of S. aureus within 10 minutes.