Microbiological testing in the Cosmetics Industry

In the US, legal responsibility falls on the company that produces the product if it is not safe in terms of microbiological contamination (this is also the case in the EU). This is despite products not requiring FDA approval before going on sale. Legal action will be taken against any company or individual that does not make sure that their products are free from harmful contaminants.1 

Contaminants can easily find their way into products through untested raw materials, poor hygiene practices at the source of production, human skin (pseudomonas, staph bacteria etc) or post production materials such as packaging.2 Due to the common use of water as a raw material in cosmetics, preservatives are often used to try and extend the product’s shelf life whilst also attempting to prevent high levels of microbiological contamination.

As the trend / market for natural cosmetics extends, the need to test more thoroughly increases. Although, what are considered more ‘natural’ (less synthetic) preservatives are now more widely available / acknowledged. However, there is some controversy regarding the efficacy of some non chemical preservatives and their natural credentials. 

In any case, water based cosmetics should have some level of preservative in, not only to extend the shelf life but also to make it safer for the end user. Even after using preservatives in a cosmetic product, it will still need to be microbiologically tested to ensure the efficacy of the preservative.

Bacteria is not the only issue when dealing with microbiological contamination, cosmetics can sometimes be breeding grounds for fungi, moulds and yeasts. This is why the testing of both bacteria and yeasts and moulds is to be taken into consideration.

High levels of bacterial contamination could indicate that pathogens may be present. This should be taken seriously as this could lead to serious illnesses and in some cases (where the patient is immune compromised / very young) even death3. Contaminated cosmetics have also caused temporary / permanent blindness in some cases.4
At the very least, a user could contract a nasty skin disease or rash.

Even if the contaminated product does not cause a reaction / infection in the user, it can spoil the product and make its appearance / odour unpleasant.

Cosmetics are considered products such as*:
Moisturiser / lotion
Make up
Shampoo and other toiletries (not including soap)
Nail polish
Hair dye5

According to the European Parliament:

“‘cosmetic product’ means any substance or mixture intended
to be placed in contact with the external parts of the human
body (epidermis, hair system, nails, lips and external genital
organs) or with the teeth and the mucous membranes of the
oral cavity with a view exclusively or mainly to cleaning
them, perfuming them, changing their appearance, protecting
them, keeping them in good condition or correcting body

Cosmetics Production

All products falling within the category of ‘cosmetic’ should be made safe for human use. This can include microbiological testing of the raw materials and the finished product itself.

Eye make up and cosmetics for infants should not contain more than 102 Cfu/ml. Other cosmetics should have no more than 103 Cfu/ml (Scientific Committee on Consumer Products specifications).7

One convenient and cost effective way for a cosmetics producer to test their products is by using a Microbial Test Kit or Dipslides. Our own Microbial kit of dipslides will conduct a general test for bacteria and yeasts and moulds. No microbiology experience is required to use dipslides as they are ready made so no need to mix up any culture medium. As well as this, it’s just a case of swabbing the sample onto the dipslide or dipping the dipslide into a sample. After this, dipslides are incubated and then after a period of time any bacterial / fungal growth can be viewed and assessed using a comparison chart.

As well as a general bacteria (which can indicate whether there is a bigger problem such as pathogens) and yeast and moulds test, more specific tests for pseudomonas, staphyloccoci and E coli can be taken. Our dipslide collection includes products that test for the above contaminants.


1 & 2 http://www.fda.gov/Cosmetics/ProductsIngredients/PotentialContaminants/ucm433748.htm
3 & 7. Neza, Edlira.; Centini, Marisanna. Microbiologically Contaminated and Over-Preserved Cosmetic Products According Rapex (2008–2014). 2016
5.REGULATION (EC) No 1223/2009 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 30  November 2009 on cosmetic products.

*in the US

All information above was correct at the time of writing.


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