When to Micro Test

We are a cosmetic manufacturer, and I learn from experience!  For this reason, I appreciate the advice I receive on this forum.  Thanks in advance!  

We manufacture a BB Cream for a private client.   The volume of the entire batch is 20-25gallons - per shade.  They have 6 shades in their range.  

We have gone through the steps initially to ensure the formula was stable and well preserved.  Preservative Efficacy Tests and Preservative Challenge Tests were done by a third party. 

When we batch the formula, our client suggests we perform micro testing BEFORE it's filled into packaging and again AFTER. I understand the reasoning for this (of course). 

However, I just want to know if this is standard in the industry.  Our problem, is that we have to store 150 gallons of bulk product while we wait for the micro test to come back from the lab - prior to filling.  How do other labs do this??? 

Any advice would be appreciated.  Thank you!


  • BobzchemistBobzchemist Member, PCF student
    Here, we gave our clients a choice - pay for using/cleaning/sterilizing 55-gallon 316 stainless steel drums until the micro test came back, or assume the risk of filling the product right away (with the understanding that they wouldn't have to pay for a contaminated batch, but that they would have to pay for the containers/components and filling machine time whether or not the batch was contaminated).
    Robert Zonis, Sr. Formulation Chemist, Beaumont Products "All opinions and comments expressed are my own, have no relation to Beaumont Products, are fully copyrighted, and may not be used without written permission."
  • In my company micro testing before and after filling is a standard step for the first three batches of any product. We send bulk samples in sterilized containers and samples in actual packaging to two different external laboratories, and perform an in-house test simultaneously to confirm results. The remaining bulk product is tightly sealed using plastic films covering the whole mixing kettle. The costs for testing of course is charged to the client. Thankfully we haven't encountered a contamination before so I wouldn't know how to deal with whole batches that are to be discarded.

    To prevent contamination of bulk products we prepare out processing area meticulously, what with all the cleaning, sanitizing, swabbing of kettles and air sampling.
  • Thank you very much @crisbaysauli and @Bobzchemist ;
    This is very helpful.  
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