How much cosmetic preservative is needed in a product formulation?

We get a lot of questions about cosmetic preservatives, so thought sharing a blog might help you all understand this very complex, and controversial cosmetic ingredient selection better. There is also a lot of misinformation on the internet about cosmetic preservatives, particularly their input and safety, so we thought we’d shed some light on this too. 




Cosmetic preservative fact #1: Broad spectrum cosmetic preservatives are needed in all cosmetic formulations where there is water

Most cosmetic formulas are a high percentage of water, which is an essential nutrient for micro-organisms. Cosmetic formulas also typically contain a lot of other nutrient rich cosmetic ingredients that micro-organisms can thrive from. Many cosmetic formulas are also around a pH of 5.5 – perfect growth conditions for a vast majority of micro-organisms. 

In other words, you have a perfect environment to grow a variety of micro-organisms in most of your cosmetic formulas! 

While fungi (yeast and mould) prefer a slightly more acidic pH environment, and bacteria tend to prefer more neutral environments, the truth is, they will happily thrive in most pH conditions of cosmetic formulas. Therefore, you need to have broad spectrum cosmetic preservative protection for all water containing cosmetic formulas. If you want to understand cosmetic preservative selection better at an entry level, please watch our can I use a different cosmetic preservative workshop.

There are a few exceptions to this rule that require careful cosmetic formulation techniques, but that requires professional training to ensure the product is still adequately preserved. You can learn more professional cosmetic preservative selection with our Certificate in Cosmetic Preservatives or one of our more advanced study options.  


Cosmetic preservative fact #2: Cosmetic preservatives have individual input requirements – not necessarily 1%w/w

It is a misconception that all cosmetic preservatives should be added at 1%w/w in a cosmetic formula. This is not correct. While several cosmetic preservatives need to be added at 1%w/w for their best performance, not every cosmetic preservative needs to be added at 1%w/w. For some cosmetic preservatives, this is far too much, for others, it is not enough. 

While suppliers will often provide quite a broad ‘range’ of inputs for a cosmetic preservative, the lower end of this range really only applies when you have a very low water input, and/or other adverse cosmetic formulation conditions (like an extreme pH, for example). In most cosmetic formulations, where there are ideal growth conditions (water, skin friendly pH, other nutrient rich ingredients) the maximum recommended input, or near to it, is required. 

We have preloaded the recommended inputs of different cosmetic preservatives into the Create Cosmetic Formulas program based on the type of cosmetic formulation and the water content present. This means you don’t need to worry about going ‘too low’ or ‘too high’ with your cosmetic preservative input. But this is also why we don’t give the broad range of input that many suppliers provide, because in many types of cosmetic formulas, their lower input would be too low to provide adequate protection for the cosmetic formulas you are creating. 


Cosmetic preservative fact #3: All cosmetic preservatives are safe when used within the correct limits

It is a common myth that natural means safe and synthetic means dangerous - for all types of cosmetic ingredients, but especially for cosmetic preservatives. The truth is, all cosmetic ingredients, when used within regulatory limits, are considered safe when used appropriately within cosmetic formulations. This also applies to cosmetic preservatives, which regardless of their source, are tightly regulated to ensure consumer safety. This means cosmetic preservatives have been closely tested to ensure consumer safety in a cosmetic formulation, even from multiple exposures from various products over time, to ensure they are still safely used, regardless of whether they are natural or synthetic. 

We’ve pre-loaded the safe inputs of cosmetic preservatives into the Create Cosmetic Formulas program to help make sure you comply, and are using your cosmetic preservative, regardless of its source, safely in every cosmetic formula. 


Cosmetic preservative fact #4: Most cosmetic preservatives are not natural – not even the ones you think are natural!

There are many cosmetic ingredients that are ‘nature identical’. This means they are identical to what occur in nature, but are synthetically produced for commercial reasons. 

Potassium sorbate and sodium benzoate are two very common examples of ‘nature identical’ cosmetic preservatives that are often incorrectly thought of as natural, when they are in fact, synthetic. They are chemically identical to how they appear in nature, but they are synthetically produced. 

There are several cosmetic preservatives that are permitted in natural and organic products – even by Certifiers – because they are ‘nature identical’, whilst knowing they are not actually natural. 

Note: it is incorrect to say your cosmetic product is 100% natural or all natural if your cosmetic formula contains a nature identical cosmetic preservative – because a nature identical cosmetic preservative is still synthetically sourced. 


Cosmetic preservative fact #5: Cosmetic preservatives are not foolproof

Even when you have made a good cosmetic preservative selection, there are so many other factors that can lead to cosmetic product contamination. These can include:

  • excess consumer interaction – cosmetic products packed in jars get re-dipped into several times, throughout use, by consumers. If they have dirty hands or the cosmetic preservative is challenged in that type of product, it can lead to contamination. 
  • other cosmetic materials being contaminated – if you have contamination in another raw material in your cosmetic formula, then it could overcome even the best preservative selection.
  • cosmetic manufacturing equipment or cosmetic packaging being contaminated – if you have contamination in your equipment during manufacture, or the air or water used, then it could overcome your cosmetic preservative selection. Similarly, if your cosmetic packaging is contaminated, then your preservative may not be sufficient to protect the cosmetic formula anymore. 

The good news is, with the Create Cosmetic Formulas program, we have taken care of good theoretical selection of the preservative and the final pH to suit each different cosmetic product form. This means if you package it right, ensure your other ingredients are in a microbe-free condition, and make sure your manufacturing equipment and packaging are pristine before production, your preservative will usually be sufficient to protect your cosmetic formula. 

There are of course always exceptions to ‘theory’ – especially when you make your samples. This is why preservative efficacy testing (also known as challenge testing) is recommended as part of any good stability program. It helps ‘prove’ the theory of your cosmetic formula, because you can never prove the theory without testing a sample! Learn how to run the essential stability tests on your cosmetic products, even as a small brand, and check the effectiveness of your preservative in its packaging and formulation with our stability testing essentials workshop. You can also learn full professional level microbial testing, stability testing and even Good Manufacturing Practice standards with our Certificate in Cosmetic Quality & Stability.  


So, how do you make the best preservative selection for your formula?

Well, the great news is we have preloaded the most effective preservative blends into Create Cosmetic Formulas for you, to help take the stress out of good cosmetic preservative selection. We have:

  • used only cosmetic preservatives with broad spectrum preservative protection available from small cosmetic ingredient suppliers,
  • entered tight ranges of input for each cosmetic preservative specific to the type of cosmetic formula you are creating,
  • made sure the Create Cosmetic Formulation program recognises the cosmetic preservative you are using, and provides the right method with the correct final pH to suit your specific preservative selection,
  • loaded any incompatibilities that may occur, so the program won’t let you choose a preservative that is incompatible with another cosmetic ingredient or a cosmetic formulation final pH requirement, and
  • provided you with information on how natural or not a cosmetic preservative blend is, so you can pick and choose between the many preservative choices provided that align with your company philosophy. 

In other words, the best theory goes into every cosmetic formula so you can worry less about making a human error. Remember to always manufacture cosmetics in a clean environment, use good packaging choices that are also clean, and check your cosmetic ingredients before using them in larger batches. Factor in your essential cosmetic stability tests to prove your cosmetic preservative is effective, and you can just get back to enjoying creating, and making, great cosmetic products. 

Happy formulating!