Can microbes live on surfaces with less than 10% humidity? I've seen it claimed that bacteria or viruses can't live on surfaces when the humidity is less than 10%. But I can't find any credible source for this. The earliest source I can find is Popular Science magazine: > Humidity also makes a difference; no bacteria or virus can live on dry surfaces with a humidity of less than 10 percent. Is this true? And if it is, where is the evidence for it?

Here is a graph from a scientific review paper by _Jawad A et al. (1996)_ called _Influence of relative humidity and suspending menstrua on survival of Acinetobacter spp. on dry surfaces._ A PDF of it can be found at this NCBI page.

![](

Here I've taken the first 6 bacteria from the experiment, and made it into a slightly clearer graph.

Quite clearly, every single bacteria here survived for 2 days or more - and _R 584_ survived for as many as 8 days.

![](

> Humidity also makes a difference; no bacteria or virus can live on dry surfaces with a humidity of less than 10 percent

This experiment seems to have conclusively shown that some bacteria can survive those conditions.