Why are preservatives added to cosmetics? The report also evaluates the pros and cons and considers the future outlook of preservative use
What are preservatives and why are they used?
Preservatives are substances which may be added to cosmetic products for the primary purpose of inhibiting the development of micro-organisms in such products. This means they are added to keep your product free from the build-up of germs !
Preservatives allow the product to be stored at room temperature or even in the humid conditions surrounding a bathroom cabinet. Preservatives even allow us introduce all sorts of new micro-organisms by sampling the produce with our hands (eg creams), without the dangers of these new germs feeling happy and at home in the product and thriving to produce nasty odours and colours in the product.
How are preservatives selected
In this country (and in most of Europe), only the preservatives approved by the European Commission, can be used. The EU commission receives its advice from a body of independent scientific experts from the member states, the Scientific Committee on Cosmetic Products (SCCP).
There is a large choice of preservatives available for use by the manufacturer, although only a handful of these seem to be commonly used. The choice and use of the preservative is determined by the product type, formulation, storage conditions, shelf life, preservative properties and costs.
Declaring use of preservatives and labelling
Preservatives, likely nearly all ingredients, have to be declared on the product label. This means if you see the wording “paraben free” in big letters on the label, then you can scrutinize the small letters of the ingredients list to see what preservative has been used instead! All the ingredients listed should use the name given in the Common Ingredients Nomenclature (INCI), so there can be no confusion due to any one ingredient having many “nicknames”!
Certain cosmetic ingredients do not have to be declared on the label, and this can occasionally mean that it may be possible to get away with declaring if a preservative is there depending on the other roles it plays in the product. Perfume and aromatic compositions and their raw materials do not have to be declared and can simply be described by the use of the word perfume or aroma. Impurities in the raw materials are not regarded as cosmetic ingredients and do not need to be shown.
The regulations specify the maximum levels of preservatives permitted in cosmetic products; however, it is possible that some products may contain higher levels due to the impurities / aromatic compositions which need not be declared!
Safety of preservatives
Despite the ability of some small molecular weight preservative materials to penetrate the skin or to enter the body through broken skin, or sites such as the mucous membranes, and reach living cells, cosmetic ingredients are not required to be food frade. There are differences in legislation relating to preservatives used in food in comparison to those used in cosmetics, for example, food manufacturers must demonstrate that a food preservative is safe by (in addition to other factors) considering the cumulative effect of the preservative in the diet, and require the additives to be food frade. Cosmetic manufacturers do not need to worry as much as the Food manufacturers about safety issues relating to preservatives or about their cumulative effect. However, there has been increased research, publicity and customer awareness in this area, which has impacted on legislation as well as customer choice, leading to increasing pressures and expense on manufacturers to change product formulations.
As functionality of preservatives is achieved through biochemical and biological effect on microbial cells, there are concerns that the preservatives may be able to affect human cells and that this may pose long term health risks to the consumer. However, preservatives have been pre-evaluated for safety and the load is regulated (ie there are maximum permitted levels in place). This means that the preservatives should not pose a serious health threat, for the majority of the consumers, where the manufacturers have prepared products in compliance with the legislation. However, there are concerns over the safety of the preservatives that are permitted, and that products may potentially contain greater levels due to the presence of impurities for instance, or their possible misuse by unscrupulous or ignorant manufacturing practice.
There have been studies carried out on specific preservatives and their possible links to health effects. The British Association for Dermatologists states that despite the intrinsic safety of cosmetic products, consumers may experience reactions to them which may be irritant and allergic contact reactions. Irritant reactions are more common then allergic reactions, and may occur following a single exposure to a substance but are more likely to occur after repeated exposure to the same or different agents over a period of time. The association also states that although most potential allergens on the consumer and industrial market have a low intrinsic potential for sensitisation, an important exception is some preservatives. The very good preservatives are usually also very good allergens. According to the Association, 8% of individuals investigated for eczematous skin conditions are allergic to preservatives. Ingredients previously considered to have a low sensitising potential have caused problems from their inclusion in particular formulations, eg by increased skin penetration by enhanced “delivery function” or because of cross reactions. This means that one known undesirable attribute of cosmetic preservatives is their potential ability to cause skin irritations or allergic reactions.
Amongst the studies carried out relating to other health effects of preservatives are the links to possible detrimental effects on the endocrine system. There have been studies evaluating the activity of parabens in breast cancer cells which have indicated a weak estrogenic effect of parabens. Parabens are alkyl hydroxyl benzoate derivatives. Subsequent studies have focussed on the use of deodorants and their possible connection with breast cancer . Although, the estrogenic effects are confirmed, the studies do not seem to have confirmed a link between parabens in cosmetics to breast cancer. However, there are still suspicions regarding preservatives cosmetic use.
Formaldehyde is also considered a cancer suspect. This is also an irritant and can trigger allergies. Formaldeyde is used in liquid soaps, and bath products as this mixes easily with water. The European Unions Scientific Committee on Cosmetics decided that Formaldehyde was safe when used at low levels. However, the restrictions only apply when Formaldehyde is used a preservative. When it is used to serve other functions eg in an antibacterial handwash, it is permitted at greater levels (up to 5 % in nail hardeners), which also must clearly display warnings. This allows the possibility for a preservative, in circumstances when it serves some other function in the product, to potentially be used at levels that would make the product more likely to pose a risk to consumer health. Antimicrobial microbial hand washes which may be permitted to contain greater levels for formaldehyde are the the type of products than may cause cumulative effects of product use over time. These products seem to be increasing in popularity in the supermarket shelves, and there are no labels present discouraging children from using such products.
Possible unscrupulous uses of preservatives
From the manufacturer’s viewpoint, preservatives can enable product preparation without have to worry about the use of aseptic techniques or even having to train staff in this area. General good manufacturing practice guidelines are sufficient enough! Customers generally do not seem to be as interested on the product ingredient lists, which are long-winded and fully of names they do not recognise. Customers are more influenced by other factors, such as brand name, or attractive packaging, or other claims made on the products labels. Therefore manufacturers do not have to worry about the customers perceptions regarding safety issues relating to preservative use. This would allow them to base their choice of preservatives on other factors, such as costs and ease of use.
Are preservatives over-used?
The manufacturer can experience problems relating to preservative use. For instance there may be the difficulties in formulating the product so that the preservatives are used most effectively, as this area may need a high level product awareness and formulation skill, as well as testing. Preservatives may be over used, under used or improperly formulated by otherwise well-intentioned chemists. Products with formulas with an ethanol content above approx 15% may not require any additional preservative. Glycols if present in the product may reduce or even eliminate the need for preservatives by reducing the water activity of the product.
Micro-organisms may breed or new ones may find their way in, if the manufacturer has not been able to accurately predict exactly how their products may be used or stored after purchase. Even if the preservative does its job adequately by inhibiting micro-organism growth, the product may still “go off” in other ways, eg by oxidation.
Preservatives and Environmental Issues
Reflecting on environmental issues, preservatives (as with other classes of substances such as pesticides or antibiotics that are used to kill or inhibit micro-organisms) may actually allow dangerous resistant micro-organisms to survive, breed, and even evolve to adapt to the “preserved” environment (ie transform into “super-bugs”). Over time, this may mean that some preservatives may become ineffective, and possibly need to be replaced with even stronger preservatives that may have been previously banned from use. Resistant micro-organisms may pose a significant health threat, as infections caused by such micro-organisms may be more difficult to treat.
Another environmental danger associated with preservatives is the possible negative impact the preservative may have on the environment when the preservative is disposed, if it finds its way into soil or in the water supply. This would cause the preservative to harm natural micro-organisms occurring in the soil and disrupt nature’s balance, or it may enable the preservatives to reach the human body through another route.
The Future Outlook of Preservatives in Cosmetics
In future, preservatives used in cosmetics may follow the trends of those in the Food Industry. There appears to be a greater customer awareness about safety of food ingredients, and ultimately the customer choice directs the manufacturing processes, but customer awareness of safety of cosmetics is catching up! Food manufactures make use of many methods of food preservation which do not require preservative use, for example freezing, freeze drying, irradiation, vacuum packaging, packaging in smaller sample packs, and other novel methods of packaging. If a complex colloidal system such as milk can be adequately preserved by spray drying and reconstituted to resemble the properties of the original product, why cannot the same principles be applied to say a lotion? Studies evaluating product performance and safety are ongoing, and these can impact on legislation.
Guidelines for the Safety Evaluation of Cosmetic Ingredients are regularly updated. It is likely that some of the preservatives currently allowed may be removed, and new preservatives may be added.
There have been some references on the use of essential oils as preservatives and particularly their synergistic effects. Such methods of preservation may enhance the quality of the product. The Aromatherapy Trade Council states that essential oils possess distinctive therapeutic properties, which can be used to improve health and prevent disease. They are readily absorbed through the skin and have gentle physiological effects. This implies that such method of preservation may actually lead to health benefits and consumers are less likely to perceive these ingredients as “nasty chemicals”. The future outlook, therefore, looks promising for the use of essential oils in preservation.
It is possible also that the future may see the legislations across the globe setting similar guidelines, leading to consumer confidence in the safety of cosmetic products. Manufactures may attempt educate consumers better on how the product should be stored and handled, so as to minimise contamination. For example, by advising the consumer store the product in a cool dry place, away from sunlight, or ensuring that they put the lid back on.
Overall, the safety advantages related to preservative use outweigh the safety disadvantages, and this is why preservatives need to be used. Hopefully, in future, the action of preservatives, and other preservation methods, will be better understood, novel techniques will be applied, and consumers will have a greater choice of products in the marketplace which are preserved in ways that do not compromise on product safety.
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2. http://www.a-t-c.org.uk – The Aromatherapy Trade Council
3. www.ctpa.org.uk – Cosmetic, Toiletry and perfumery Association Ltd
4. www.colipa.com - the European Trade Association representing the interests of the cosmetic, toiletry and perfumery industry
5. Cosmetic Safety, Guidance on the implementation of the cosmetic products (safety) regulations 2004, DTI, April 2005
6. “ A fresh look at preservatives” U.S. Food and Drug Administration. FDA Consumer. October 1993.
7. www.bad.org.uk – The British Association for Dermatologists
8. www.nyscc.org - New York SCC
9. Journal of Biochemistry and Molecular Biology (January 2002, pages 49 – 60)
11. The Scientific Committee on Cosmetic Products and Non-Food Products intended for Consumers. Opinion concerning “The determination of certain formaldehyde releasers in cosmetic products”
13.Lett Appl Microbiol. 1999 Apr;28(4):291-6.
14 .Lett Appl Microbiol. 1998 Mar;26(3):209-14.
Written by Kalpna Kotecha, Cosmetic Scientist, Spa Isha Aromatherapy