You’d be hard-pressed to find a skincare product that has noticeably gone ‘expired’ thanks in large part to a family of ingredients known as preservatives. But the key is knowing which preservatives to avoid and, when it comes to eye care, to always go preservative-free.
Bottom line: treat skincare and eyecare preservatives differently.
Preservative’s play an important role in modern day skincare – allowing us to use formulas (particularly those containing water) for longer and keeping us safer while we do use them by preventing the growth of bacteria or mould. They do this, by creating an inhospitable environment for the bacteria, fungi or yeast to breed. Since bacteria and co. thrive when they are in or around pH neutral formulas (around pH 6 – 9), most preservatives (such as acids; benzoic acid) create a slightly acidic environment in the skincare container (around pH 5.5) or, less common, a slightly alkali environment (around pH 10) to discourage the growth.
It is widely agreed that as preservatives help to keep products free from much more invasive and harmful microbes, they are a necessary additive to most skincare products and absolutely essential in water-based skincare.
The key is to avoid the small handful of preservatives that are known to have a sensitising reaction (or at worst case, allergic reactions) on skin. Scan your product ingredients labels to opt for the more gentle of the preservatives, especially if you have sensitive skin, to get the best of both worlds.
One family, of preservatives, parabens, have gotten a bad rap recently after a series of studies linked paraben use in cosmetic products to health issues, particularly for disrupting hormone production in women. Many of these claims have since been questioned for improper research methods (for example, for extrapolating broad conclusions based only on in vitro (petri-dish) studies) or for using exaggerated concentrations of parabens in the studies (for example, using 100% concentration of parabens, when, in reality, cosmetic products can legally only use up to 25% concentration and normally use less than 1% concentration). Never-the-less these studies are a source of great controversy in the skincare community.
The bottom line is, if you choose reputable products that use good quality preservatives you will benefit from more hygienic skincare that you can use for longer.
Preservative-free is better for your eyecare, but not necessarily, your skin or haircare.
It is important to note that, when it comes to preservatives, products used on your eyes need to be treated differently to those used on your skin or hair. When it comes to any product that you use on your eyes; especially eye drops, eye sprays or contact lens solutions but also any eye makeup removers, eye lash growth serums make sure they are preservative-free.
The main reason to opt for preservative-free eye care products is that some preservatives, especially one called benzalkonium chloride (BAK), have been found to damage the cornea (the front ‘window’ and main protective barrier of your eye) at a cellular level and increase inflammation.
With regular use (for example, if being used 4 or more times per day), these preservatives can cause redness, irritation, allergies and even induce dry eyes rather than treat it!
So when it comes to any product that is in direct contact with your eye, it is much better to opt for preservative-free, especially if you already suffer from dry eyes.