Home Cosmetic Science Talk Formulating General wisdom on Challenge Tests

  • General wisdom on Challenge Tests

    Posted by mikethair on June 9, 2018 at 9:40 am
    Have had a few differing opinions on the Challenge Testing of a new Hair Conditioner formulation.  We have had good results on the original formulation. Now another customer wants the same formulation, but with different fragrance.  Some say no need for a new Challenge Test, others say it would be required.
    Genereal opinion here?
    Thanks
    Sibech replied 6 years, 5 months ago 3 Members · 2 Replies
  • 2 Replies
  • MarkBroussard

    Member
    June 9, 2018 at 12:13 pm

    Highly unlikely that just changing fragrance would cause a fail on a PCT, but your best bet from a legal liability perspective would be to do the PCT on the formula revised with the new fragrance and charge-off the cost to the client requesting the fragrance change.

    Why take the risk for the sake of saving $500? … If the delay in getting into production is the issue, make one batch to get the client going, do a plate count on the batch and cull out a sample to send for PCT.

  • Sibech

    Member
    June 9, 2018 at 1:07 pm
    While for the most part agree that it is highly unlikely that a change in perfume will affect the PCT it is important to mention that a several of the organoleptic compounds in perfumes have a distinct impact on microbes.
    Therefore the concentration of fragrance you use (which in rinse-off can become significant proportion) and the actual composition of the fragrance makes could impact it.
    Rule of thumb: If in doubt, err on the side of caution and do a PCT. Depending on the company they will gladly give you a preliminary result after the first 2 weeks, and in my experience, they seldom fail after 28 days if they passed the first two weeks.

Log in to reply.

Chemists Corner