Are parabens, formaldehyde and MIT still needed?

Much more, it is a potential risk for the consumer and legislation therefore demands a safe preservation and thorough microbiological testing of finished products. However, the image of preservation, or more precisely of certain preservatives, by the consumer is normally negative. There is little controversy among experts that efficient preservation is essential for the safety of cosmetics. But, naturally, as there are many choices of preservatives, there are different opinions about what can be considered the best of so many choices. Many different topics may have to be considered for choosing the right preservative. First of all it is the demand of safe and efficient elimination of microorganisms. This seems obvious, but not every preservation system works in every formulation. There are essential mistakes made in formulating by using preservatives that may work in one formulation, but are inhibited by certain ingredients and ineffective in others. A second issue is the use of a widely accepted and validated methodology for microbiological testing. A number of suppliers of preservatives offer microbiological services (challenge testing) that are different to the methodology recommended by experts and authorities around the world (i.e. the challenge test according to USP, BP, Ph. Eur. ISO 11930 etc.). The mentioned validated methods used throughout the world all have in common that the same test organisms are used under comparable testing environments. In contrast to this, some preservative suppliers believe (or want to make customers believe) that a testing for safe preservation needs a cocktail of germs and repeated inoculation of the test sample. This methodology has weaknesses (e.g. repeatedly diluting the product’s preservation), low reproducibility and may lead to an excessive dosage of preservatives. An unnecessary high dosage of preservatives should be avoided for many reasons. It leads to higher formulation costs, but more important, is one of the reasons for an increasing number of adverse skin reactions to preservatives as stated by a number of studies in recent years. Thus, by recommending excessive dosage of preservatives, based on the shortcoming of their own microbiological methodologies, suppliers are helping to ruin the image of preservatives in general.

State of the art paraben replacement

It is surprising to see that every year hundreds of new cosmetic ingredients are introduced in the market, while the choice of cosmetic preservatives remains more or less the same. On one hand a certain conservatism in this field is acceptable, because preservatives are well documented and risk assessment is calculable. On the other hand there is growing evidence about skin incompatibility with some (not all!) conventional preservatives. Serious studies around the world are showing this trend and published data about skin allergies, sensitisation and other adverse effects caused by preservatives is readily available. The data should be used carefully and wisely, certainly not to scare consumers. But this data must not be ignored either. The past few decades have brought more light also on certain problems connected to the use of preservatives. More and more cosmetic manufacturers are moving away from many traditional preservatives. Some preservatives, like parabens, have been criticised for many years and replacement of these have led to a more frequent use of formaldehydereleasers or isothiazolinones (CMI/MIT or other MIT mixtures). These ingredients obviously do not have a better dermatological profile compared to parabens, but, sadly, are often used to claim ‘Paraben Free’. Some reactions in the market (like the recent announcement of multinational companies to stop using formaldehyde-donors) have shown that this route may not be the right one to take.