So I"m checking the water fountains in our shop for bacteria. I used a dip slide that incubates in 24 hours to see if they need to be disinfected. There are two fountains and I had three slides in my pocket so I dipped one in the band saw cutting lubricant. A white water based metal working fluid (MWF). I had just finished a safety course on MWF's and became aware that bacteria can grow in it. (I really coud not believe bacteria would be able to survive in the stuff.) I could not resist checking it. The next day I checked the slide. Over 1 million colony forming crittters on the slide. Amazing! Now I'm thinking, better wash my hands after using the band saw. And better let the guys in the shop know too! What is/are the Best Practice(s) for disinfecting MWF's?