So,.. you have the winning formulation your hands, you have tried and tested it on friends and family and it has consistently worked its magic on them. And now…. you are wondering what next…?

Well, let me begin by telling you that you are not alone on this journey. There are many of us who are at that same crossroad…  not lost but searching for the answer to the all important question… “where do I go from here”?

I hope that if like me you are in that situation, this post will help in giving you have some momentum once more.

First, lets start with what not to do:

Don’t rush off into your lab and start making products for sale!.

What to do:

Before you ever begin to start selling your products commercially, your products have to undergo a series of lab tests to ensure their safety.

And yes.. you have employed good manufacturing processes in making your products and of course you used a preservative… but, there is more beyond what the eyes can see that go in in the microbial world and the only way to know exactly how safe or otherwise your products are is to test them.

What are these tests? At the basic minimum you need the following tests:

  1. Microbial Challenge Test or Preservation efficacy test (PET)

The efficacy of the preservation of a cosmetic product under development has to be assessed experimentally in order to ensure microbial stability and preservation during storage and use.  This is done by challenge testing and is mandatory for all cosmetic products that, under normal conditions of storage and use, may deteriorate or form a risk to infect the consumer.

A challenge test consists of an artificial contamination of the finished product, followed by a subsequent evaluation of the decrease in contamination to levels of acceptable microbial limits . The evaluation of the preservation of a cosmetic formulation is based on inoculation of the product with calibrated inocula (prepared from relevant strains of micro-organisms). The number of surviving micro-organisms is measured at defined intervals during a period of 28 days. For each time and each strain, the log reduction value is calculated and compared to the minimum values required for evaluation.

  • Pseudomonas aeruginosa
  • Staphylococcus aureus
  • Candida albicans
  • Aspergillus brasiliensis (previously A. niger)

The responsible person must guarantee the efficacy of the preservation of  their products experimentally by challenge testing.

The preservative efficacy test (PET) is a microbiological evaluation of a product’s ability to kill or prevent the growth of microorganisms over a period of time.

This test does not check the ingredients of product or test the suitability of the product for a given application, the purpose is to prove the preservative system in the product ensures bacteria are not allowed to grow.

A Preservative Efficacy Test (PET) is only required when a product contains water. When a product contains no water, bacteria cannot grow and therefore the test is not required. The definition of water includes floral waters as they harbour the same ability to allow bacteria to grow.


2. Stability test

The purpose of stability testing is to ensure that the cosmetic product maintains its intended physical, chemical and microbiological quality, as well as functionality and aesthetics when stored under appropriate conditions.

Stability tests access the following factors in relation to the product:

  •  How the product will hold up in normal conditions of storage and use as well as consider the products under various stresses, high and low temperature differences etc
  •  Consider evaluation of critical aesthetic properties such as colour, fragrance, texture, and flow, particularly after exposure to          conditions designed to stress each specific property.
  •  Consider variation in process conditions.
  •  Consider the impact of packaging on the contained product, as well as any effects which the product might have on the packaging
  • The purpose of a stability test is to assess the chemical, microbiological, physical stability of a product. The test assesses whether the quality, functionality and aesthetics when stored under appropriate conditions are maintained to a level that should be expected of the product.
  • The testing data will determine the expiry date for your products.
  • Stability information is a requirement of the Cosmetic Product Safety Report (CPSR).

3. Cosmetic product Safety Report (CPSR)

In the E.U this is mandatory test for any product that will be soldtothe public. it requires the manufactures to supply details of all the ingredients used in making the product including the MSDS data of each product. Once you submit your data for your Cosmetic Product Safety Report, a toxicologist will initially look over your formula*to examine the cumulative effects of many of your ingredients as well as ensure you are not using any banned ingredients.  There are  regulations on the maximum percentages of many products as well as their effects when combined with other ingredients.

If  there are any problems with your formulation, you will be contacted and told where your product breaks EU regulations. You should then reformulate your product and resubmit your revised formulation**.

When the basic formulation is created and accepted, your toxicology report will be prepared.  The following points will be outlined in the toxicology report :

  • Toxicological Content, with ingredient toxicology reviews
  • Safety Labeling Advice
  • Product Analysis
  • Labeling Suggestion for Ingredients
  • Toxicological and Regulatory Review
  • Provide a Sign off
  • Any specific details about warnings and precautions you should include on your label.

Usually the cosmetic product safety assessment  cannot be completed without microbial preservative testing if your product contains water and recommendations about the shelf life of the products cannot be made without stability testing.





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