Preservatives are a must in cosmetic formulations, and every product uses different types of preservative systems. Here we will discuss why we need them and how we can identify them in our hair products.
The importance of preservatives
Because cosmetic products have plentiful water and other nutrients, as well as a hospitable pH and temperature, products are potential breeding grounds for microorganisms. Preservatives act as antimicrobials to prevent the growth of molds, yeasts, and bacteria in our products. They are essential for stability, odor, appearance and texture to extend the shelf life of our products. Most importantly, they are important for consumer safety. Without them, cosmetic products can become contaminated, leading to faster product spoilage and possibly irritation or infections. These preservatives are usually effective at very low levels ~ 0.1%-0.5% wt.
Commonly used preservatives in hair care
There are many options for preservatives with the synthetic ones being the cheapest and most effective at extending shelf life. Researchers are now looking at more natural options because of all the health concerns in the past few years regarding preservatives. The list below shows some of the common preservatives. The asterix (*) marks the ones that are known to have major health concerns. [To be discussed in another article].
Natural preservatives are not as popular because they are more expensive, and any one preservative is not efficient by itself against the different types bacteria, fungus etc.: their scope of protection is limited. For that reason, several types of natural preservatives need to be used together synergistically to achieve the desired level of protection. This causes the cost of the products to go higher.
- Dmdm hydantoin*
- Imidazolidinyl Urea*
- Imidazolidinyl Urea II*
- Benzyl alcohol
- Sodium benzoate
- Quaternium-15 *
- Parabens*: methylparaben, ethylparaben, butylparaben [Read more about its health implications here]
Some naturally derived preservatives
- Potassium sorbate and sorbic acid
- Citric acid and its salts ( Diammonium citrate, Potassium citrate and Sodium citrate)
- Rosemary oil extract
- Neem oil extract
- Lavender oil
- Tea tree oil
- Grapefruit seed extract
- Vinegar (acetic acid)
Regardless of whether synthetic or natural preservatives are used, the goal is to keep the products clear of any microorganisms. Some products with expired shelf life may look and smell fine, but they might actually have started to grow bacteria, fungus or other organisms which can be detrimental to our well-being. The reason is that the activity of the preservatives will stop/diminish after the suggested shelf life of the product. So, ladies: check your cabinets for old products. It’s probably time to toss them out anyway if they’ve been sitting in there for that long! 🙂