Are Natural Cosmetic Preservatives Safe? Cosmetic Laboratory Testing Has the Answer!
Skin infections are a serious global health problem. These infections are influenced by many factors, including place of residence, health condition, individual sensitivity, and cosmetic or skincare use. According to data from the Global Burden of Disease (GBD) study, fungal infections account for about 34% and bacterial infections about 23% of all dermatological conditions.
The most common fungal species include Candida albicans, Rhodotorula spp., Malassezia furfur, and Aspergillus spp., while the most frequent pathogenic bacteria are Escherichia coli, Klebsiella, Pseudomonas aeruginosa, and Staphylococcus aureus. Bacterial and fungal skin infections can range from mild to severe, each presenting with different symptoms. Furthermore, the growing issue of antimicrobial resistance among fungi and bacteria has become a major global health concern.
With the increasing demand for antimicrobial agents, researchers have developed natural antimicrobial alternatives that may help prevent various skin diseases. Natural antimicrobials are classified into plant-based, animal-based, and mineral-based sources. This article discusses the types, effectiveness, advantages, and disadvantages of each category of natural antimicrobials.
- Plant-Based Natural Antimicrobials
- Animal-Based Natural Antimicrobials
- Mineral-Based Natural Antimicrobials
- Are Natural Antimicrobials in Cosmetics More Effective?
Plant-Based Natural Antimicrobials
Plant-derived natural ingredients can possess antibacterial and antifungal activity against microorganisms that cause mild skin infections. These substances are typically secondary metabolites extracted from plants. Plant extracts can help treat chronic skin diseases or serve as preventive agents.
Some commonly used extracts and essential oils in cosmetics with antimicrobial properties include garlic, sage, tea tree oil, lavender, and aloe vera. Garlic is known to contain antimicrobial compounds such as chlorogenic acid, p-coumaric acid, and thiosulfinates, which exhibit activity against Candida albicans, Candida parapsilosis, Staphylococcus aureus, and Escherichia coli. When applied to the skin, sage provides antioxidant, anti-inflammatory, and antimicrobial effects due to its essential oils rich in oxidized sesquiterpenes.
Tea tree oil is widely recognized for its strong antimicrobial activity. Its main bioactive compounds include terpinen-4-ol, γ- and α-terpinene, α-terpineol, 1,8-cineole, p-cymene, α-pinene, and limonene. Studies show that tea tree oil is more effective against S. pyogenes and P. aeruginosa compared to antibiotics such as rifampicin, cephalexin, and erythromycin. Aloe vera is a widely used plant in the pharmaceutical and cosmetic industries due to its anti-inflammatory effects, wound-healing properties, and broad antimicrobial spectrum. It is commonly used in after-sun products, anti-acne formulations, and skincare products for dry skin.
Animal-Based Natural Antimicrobials
Animal-derived natural antimicrobials are active substances obtained from animal sources, such as honey, beeswax, propolis, collagen, chitosan (from shrimp shells), and lanolin (from sheep’s wool). Because of their antibacterial, moisturizing, and wound-healing properties, these ingredients are widely used in cosmetic formulations.
Propolis, for example, is a mixture of plant resins and bee secretions containing phenolic acids and flavonoids—compounds that contribute to antimicrobial and antioxidant activities. Overall, animal-derived ingredients are effective for skin treatment and support the skin’s natural protective functions.
Mineral-Based Natural Antimicrobials
In the cosmetic industry, mineral-based natural antimicrobials can be found in clay, mineral water, and mineral mud. Several studies have reported that these minerals exhibit additional antimicrobial activity, making them widely used in cosmetics. However, their direct effectiveness on the human body has not yet been fully demonstrated.
Read more:
Preservative Effectiveness Test: An Important Step to Keep Products Clean and Safe
Are Natural Antimicrobials in Cosmetics More Effective?
Natural and organic cosmetics are becoming increasingly popular because they are perceived as safer and better than synthetic products. However, the use of natural ingredients also carries certain risks. Some natural substances, such as essential oils and plant extracts, can cause skin sensitivity or allergic reactions, including redness, itching, or rashes.
Moreover, natural cosmetic products are more prone to microbial contamination because they often lack synthetic preservatives. Thus, the effectiveness of natural ingredients in cosmetics cannot always be guaranteed. Their effectiveness depends on their chemical composition—complex chemical structures can reduce antimicrobial potency and shorten shelf life.
Studies suggest that the effects of natural ingredients on the skin are highly dependent on their chemical composition and concentration. When used as antimicrobials in cosmetics, natural ingredients alone are not sufficient to ensure a product’s effectiveness against pathogenic skin microbes, as the product’s performance still depends on the formulation and concentration of active compounds.
To ensure that natural antimicrobial ingredients in cosmetics are truly effective and safe for use, scientific validation through cosmetic laboratory testing is essential. Tests such as antimicrobial activity assessment, product safety evaluation, and formulation stability testing help confirm that active ingredient concentrations are appropriate and that products are not at risk of microbial contamination. IML Testing & Research is ready to support your cosmetic testing needs to ensure product safety, quality, and consumer trust.
Author: Safira
Editor: Sabilla Reza
References:
Mlynarczyk, D. T., Glensk, M., & Krzyzanowska, J. (2023). Natural substances with antimicrobial properties in the treatment and prevention of skin infections and their application in cosmetic products. Cosmetics, 12(1), 1. https://doi.org/10.3390/cosmetics12010001
