I’m curious. After doing some household cleaning this weekend, I noticed that the can of household cleaner I was using claimed to kill “99%” of bacteria. What happened to the other 1%? Are they immune? Please enlighten.
My guess is that the 1% is resistant w/a combo of the legal dept knowing that 100% is hard to gurantee…
…and by using anti bact sprays, we keep leaving behind the most spray resistant bacteria…sort of like a condensed version of evolution, put into warp drive by human intervention.
Did you get into all the cracks and crevices? Also that 1% could be the CYA clause so you can’t sue them for false advertisement. 
yeah, the most common sense answer would be the law aspect of it. It’s just funny that no one ever claims 100%. It’s always "99.99999%!