Application Guide : Preservatives

Cosmetic formulations can be bug heaven as many contain nutrients in the form of oils and waxes, have a high concentration of water and sit at a very bug-friendly pH of between 5-8. In addition many products are stored in the hot and steamy bathroom and endure being poked and prodded time and time again by contaminated fingers! Being a cosmetic is a tough job and being a natural cosmetic can be even more challenging.

All cosmetic products need to be safe and effective preservation can help you achieve that. The seventh amendment of the 1976 Cosmetic Directive in the European Union (76/768/EEC) made it a requirement that all products sold in the EU include results of preservative challenge tests in their product dossiers to ensure that it can withstand the rigours of 'real life'. A challenge test (also know as a Preservative Efficacy test) involves adding a known range and concentration of micro organisms to the product under test conditions and measuring changes in their numbers over time. For example, a cream may have a set number and type of microbes added on day one before being put into a temperature and light controlled storage facility. The product would then be evaluated after 24 hours, 7 days, 14 days and 21 days to measure the microbe count. If the formulation stand up to this, the mix can be re-challenged at one of the test windows to see how it goes. Each re-contamination of test bugs is classed as a 'cycle' and this cycle can be completed a number of times. Results of these tests give the product owner a good idea of how tolerant their product is to repeat exposure to microbes as it mimics the situation that occurs when fingers are dipped into a jar time and time again. Although it is not a legal requirement in Australia, to have this data on file for a formulation it is a good idea as it is illegal and dangerous to sell a product that unsafe for use.

With that in mind you are more likely to succeed in producing safe products if your preservatives system is in order and that means having broad-spectrum protection at the right level.
There are hundreds of preservatives on offer and it can seem like a bit of a mine field trying to choose what is right for you. However, with a little knowledge and planning you can save yourself some time, money and stress and ensure that your products go the distance!

Here are some tips on deciding what to go for:

1. Are you formulating an Organic product? If so you will have to choose from the list of approved preservatives. (PDF Data Sheet)
    
2. Does your have to be all-natural or is nature-identical OK?
    
3. What is your budget? Preservatives range in price from $30 per Kg up to over $500. This can make a lot of difference to your final pack price.
    
4. What is the pH of your finished product? Not all preservatives work at all pH's .
    
5. Is it a leave-on product such as a lipstick or is it a rinse-off such as a shampoo? Some preservatives are not allowed in leave-on products or are restricted in their use.
    
6. Are you planning to sell outside of Australia? The rules over which preservatives are allowed are different in each country. If you plan to sell globally you need to formulate globally!
    
7. What packaging are you going to use? Some natural preservatives will not stand up to the exposure that a jar brings. You may need to use an airless pack, a tottle or a pump. You may also have to consider selling in smaller pack sizes if you can't achieve the shelf-life you desire.
    
8. Can you get your preservative of choice into your formulation? Some preservatives come in powdered form and may be difficult to add. Others are not water soluble and require pre-mixing.
    
9. What else is in your formulation? Some preservatives are incompatible with some ingredients. Problems can occur with some surfactant systems, certain silicones and some levels of oily ingredients. Also many natural ingredients such as herbs, unprocessed butters and clays have a tendency to have a high bug count BEFORE you do anything, using high quantities of these ingredients means that you need to take extra precautions.
    
10. What about your company philosophy? Some brands state that they 'do not contain' certain chemicals. Make sure that you are not adding them with your preservatives!

While the costs of purchasing the right preservative system and running preservative efficacy testing may seem like something that you just don't have the budget for, it is a whole lot cheaper than either a product recall or a consumer claim. New Directions is happy to support your effort to create the best, safest and greenest products by importing a range of both new-technology and tried-and-tested cosmetically approved preservatives and preservative blends. In addition to that our technical team are always happy to support you in providing the information and assistance that you require.

Happy formulating!

Amanda Foxon-Hill

29 Sep 2010