Pseudomonas–The Nemesis of the Cosmetic Industry

By: Donald Orth, PhD

Posted: September 24, 2009

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If you were to ask 100 manufacturers what microorganism has caused the most problems in the cosmetic industry, my guess is that nearly all of them would say Pseudomonas. Chapter 8, Pseudomonas—The Nemesis of the Cosmetic Industry, takes a look at this microorganism and the nutritional diversity and survival strategies that enable it to grow in DI water, in 28% ammonium lauryl sulfate, or in 50% quaternary ammonium compound (QAC) sanitizer. Oh yes, and cosmetic products!

Many public water systems add chlorine to their water supply (chlorination) for the purpose of disinfection. Disinfection kills or inactivates harmful microorganisms which can cause illnesses such as typhoid, cholera, hepatitis and giardiasis. Unfortunately, the levels of chlorine used may not be sufficient to kill all pseudomonads, and low levels may remain in the incoming water to introduce these microorganisms to the water treatment system used for making DI water. Water is also used for cleaning the plant, and hosing off equipment can introduce Pseudomonas spp. or other microorganisms into the manufacturing area. Any water residues can begin the cycle of contamination. People walk on moist floors, they touch wet equipment, and they work on production lines. Even when disposable latex gloves are worn, sooner or later someone will touch a contaminated surface and then transfer microorganisms to the process stream.

Pseudomonas contamination of finished products is a serious issue because some strains, such as P. aeruginosa, represent significant health risks to consumers who use the products. The most responsible action is to destroy the batch of product and to correct the problem so that it does not happen again—easy to say, but often hard to do… The survival strategies of pseudomonads will be discussed in Chapter 8 to help give perspective as to why they present such a challenge to manufacturers. Recommendations for dealing with Pseudomonas and other house organisms will also be presented.

Once pseudomonads become established in a manufacturing plant, they are difficult to eradicate because they make biofilm that helps protect them from detergents, sanitizing agents, and biocides. The most effective way to deal with Pseudomonas house organisms is to insure that raw materials and DI water meet appropriate specs, that preservative systems meet appropriate acceptance criteria, that cleaning and sanitization procedures have been validated and are being followed without deviations, and that the micro test methods are capable of recovering viable microorganisms present in products. When everyone understands this and implements appropriate specs, tests and procedures, Pseudomonas will no longer be the nemesis of the cosmetic industry.

This information is an excerpt from the book Insights into Cosmetic Microbiology, published by Allured Books. For volume orders, contact Marie Kuta at 630-653-2155.