• Formulating

  Distilled water contamination

  Posted by Anca_Formulator on August 7, 2022 at 2:53 pm

  Hi,
  I micro tested some distilled water from a just-opened jug of distilled water (store bought) and for the 1st month there was no visible activity. This is what it looks like after 3 months. I checked and the micro slide is not expired…
  What am I looking at? Penicillium Chrysogenum? 

  This is the water I use in my emulsions… :astonished: Is this normal? Isn’t distilled water supposed to have had contaminants removed? What water should I use instead?

   

  evchem2 replied 1 year, 8 months ago 3 Members · 4 Replies

  • contamination
  • distilled-water
  • microbial-testing
• 4 Replies

• 

  PhilGeis

  Member

  August 7, 2022 at 5:09 pm

  This is a paddle culture?
  Tho’ one usually sees bacteria (esp. pseudomonads), distilled water does grow bugs.   I’d complain to the supplier.

• 

  evchem2

  Member

  August 10, 2022 at 12:34 pm

  You’ve had the jug open for 3 months? I’m not surprised something would show up after continual opening and reuse

• 

  Anca_Formulator

  Member

  August 10, 2022 at 6:47 pm

  @EVchem No, I opened the jug and did a paddle culture right after opening. It is the paddle culture that developed  the nasties after 3 months.

• 

  evchem2

  Member

  August 10, 2022 at 9:04 pm

  @Anca_Formulator i see thanks for clarifying. I’ve never used the paddle culture, but isn’t it the same issue? The paddle’s been exposed to air for the past 3 months?  Even if the kit is not expired once you’ve exposed it I think the most reliable results are probably the ones after the ~120 hours/whatever the paddle supplier recommends.

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