One of the most emotive issues in cosmetics is the desire for natural materials and the avoidance of synthetics. Various campaigns have indicated that cosmetics are toxic time bombs and can do a lot of harm. All cosmetics produced in Europe by law have to list their ingredients. Preservatives are used in small amounts and as INCI lists are written in descending order of content, they normally appear at the end of the INCI listing, with long, complicated chemical sounding names. In the Health Food shops, there are often products that claim to be preservative free or contain natural preservatives. How can that be?
Creams, lotions, oils, cosmetics are rarely used fresh – i.e. used within hours of manufacture. Such items that appear on our bathroom shelves, dressing table, drawers etc. in real life are not looked after very well. If we like and favour natural cosmetics, we have to understand that all living natural substances degrade, go off. Fruit left in a bowl for a long time goes mouldy, butter goes rancid, bread gets mould – we have all seen this. The natural state of raw materials once they are harvested or gathered is to degrade. When we have food in our homes we have to preserve it. We can do so by pickling, by refrigeration, by drying, by using preservatives such as alcohol. Many of the foodstuffs we buy from supermarkets have small amounts of preservatives added to them. These are taken into our bodies and much of the objection to preservatives is based upon these preservatives in the food chain. Strangely enough, such intake of toxic substances does not get the publicity that preservatives in cosmetics do.
All around us, unseen, are bacteria – yeasts, moulds and fungi, some good some bad. When we put our fingers into a pot of cream we put bacteria into that pot. When we open a pot of cream, even to look at it, bacteria will find their way into that pot. When we open a bottle of oil the air, being full of the spores of yeasts, moulds and fungi, will contaminate the oil. Most importantly, from the point of oil, air itself is made up of gases, one of which is oxygen and oxygen burns and degrades oil. All these processes are natural, but we have to realise with clear minds that this is real nature, this is what happens in real life. Nature goes off and so natural cosmetics will go off unless there is a preservative.
The ideal preservative does not exist. By their very nature preservatives kill things. As no single ideal preservative exists manufacturers tend to mix them together using a preservative system.
Most cosmetics consist of water and oil as an emulsion. Water supports bacteria growth, oil does not but oil can support yeasts, moulds and fungi as may also water. Oils are prone to oxidation and rancidity. The more an oil is unsaturated the more likely it is to go bad.
Demand for effective and safe preservatives has never been higher, but with consumers and regulators alike turning against some well used and preferred synthetic preservatives the industry has to find alternatives. There is a preservative crisis little known outside the industry. Regulated restricted lists of preservatives are closed and with testing bans it is difficult to develop new and safer preservatives. A cosmetic product is expected to have at least a 30-month shelf life.
Whilst many essential oils have an antimicrobial function they are mostly not registered in any regulatory format as a preservative. Standard tests exist such as the challenge test (ISO11930:2012) whereby the specified microbes must be rapidly killed. If they pass the test, then thee product has a preservative element and it would be misleading to say the product has no preservative. With more interest in the biome and skin bacteria preservation there is interest in creating a hostile environment for pathogenic bacteria. It is in this area that essential oils are considered but this is controversial especially if misleading claims are made such as ‘preservative free’ when it has a preservative action but the reason for its addition is touted for its fragrance rather than its activity. Such dual action needs some explanation and clarification.