You Can’t Trust Your Eyes to Determine "Clean"

What looks clean isn’t necessarily so, according to UK researchers after performing 3,000 tests to determine cleanliness levels in a hospital setting. 


Scientists Cooper, Griffith, Malik, Obee and Looker compared areas that looked clean with the actual organic soil (via ATP) and/or microbial load (via microbe counts) present on surfaces, and found there were significant differences between areas that appeared clean and actual hygiene levels.


Their conclusion? “Cumulatively, the results indicate that visual assessment is not a reliable indicator of surface cleanliness or of cleaning efficacy.”

Abstract: American Journal of Infection Control