Effects of Commonly Used Preservatives in the Cosmetics Industry
Our skin is the largest organ of our body. It acts as a protective barrier against external influences and helps control thermal regulation, infection and other functions. Our environment, including the cosmetics we apply to it, has an impact on how our skin reacts and adapts.
The skin’s pH level is optimal between 4-6.5. The pH level of a medium denotes its acidity or alkalinity. Many microorganisms (e.g., bacteria, fungi, yeast) cannot survive in pH levels below 4 or above 10, but thrive in pH levels similar to our skin.
While we can create products at the pH extremes to prevent microorganism growth, the products will most likely irritate or damage our skin. As a result, preservatives are required to create an uninhabitable environment for microorganisms while maintaining the optimal pH level for our skin’s health.
In general, a preservative should have a broad spectrum of activity, such as sufficient water solubility and pH-independent activity.
The most common antimicrobial preservatives are divided into several groups according to their chemical structures and functional groups: organic acids, alcohols, phenols, aldehydes and formaldehyde donors, isothiazolinones, biguanides, quaternary ammonium compounds, nitrogen compounds, heavy metal derivatives and inorganic compounds.
Under the right concentration and formulation specifications, each of these protective groups has a different mode of action and spectrum of activity. The use or concentration of certain preservatives may be restricted depending on the product type and area of application.
As previously stated, preservatives are commonly used to protect cosmetic products from microbial contamination. Considering at the issue from a different perspective, it has been discovered that some preservatives can increase oxidation in O/W emulsions.
This has the potential to harm product quality, efficacy, and consumer health and well-being. As a result, the effect of preservatives on oxidation should be investigated.
People are exposed to a wide range of chemicals in their daily lives many of which are naturally occurring in the environment but others are derived from human activities and can be found in food, water, and a variety of daily cosmetic and hygiene products.
Preservatives, which are used to extend the shelf life of products, are one of them. However, there are concerns about the use of preservatives in cosmetics.
Many antibacterial preservatives have been linked to a variety of human health issues. The skin is the primary route of exposure. Children who are exposed to protective compounds at a young age have a higher risk of developing allergies, asthma, and eczema.
Human skin acts as the first line of defense against infectious and toxic external factors and is rich in various microorganisms called microbiota, such as bacteria, viruses, yeast, fungi and archaea.
In recent years, it has been reported that the skin microbiome plays an important role in human health. In addition to human innate immunity, the large population of microbes living on the skin forms the skin barrier that keeps the skin healthy.
When the balance of the skin microbiota is disturbed, the diversity and population of the microbiota change. In these cases, the individual’s skin becomes more sensitive to the effects of external factors, and the prevalence of various skin diseases rises.
In fact, the antimicrobial preservatives we use to protect cosmetic products not only kill the harmful bacteria on the skin, but also harm the beneficial bacteria and disrupt the balance of the microbiota. As a result, skin diseases such as skin irritation, eczema and allergies occur.
Recent studies have discovered that some raw materials used as preservatives affect thyroid hormone metabolism and are a potential endocrine disruptor, in addition to skin diseases and allergic reactions. An organic compound used as a preservative as well as to treat acne has recently been added to the list of endocrine disruptors.
In fact, some preservatives were found in high concentrations in breast milk and urine samples. This demonstrates that exposure affects the circulatory system in addition to the skin and respiratory tract. In addition, some of the preservatives have the potential to be carcinogenic, neurotoxic, and harmful to the reproductive organs and ocular surface.
These cosmetic preservatives not only harm humans, but also the environment and sea creatures. Some preservatives found in groundwater and seawater are toxic to aquatic organisms. In 15 years, the number of fish in the Sea of Marmara decreased from around 120 to around 10. The use of preservatives, which are toxic to sea creatures, plays a significant role in this decrease.
The quest for beauty began thousands of years ago. It continues today with an unending passion. Cosmetic manufacturers should be encouraged to use preservatives that are suitable for green chemistry, with increased efficiency, adjusted dose rate, non-harmful to microbiota.
Another option that has recently come up is to reduce the use of preservatives by developing water-free formulas, or even eliminate them entirely to protect water resources. The world is our common home and it is our duty to take action as quickly as possible so that we can live a sustainable life here.
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Dr. Tuğba Sağır
Biotechnologist / R&D Manager
Pim Grup
