Defining what is meant by natural is the first hurdle to overcome, as the term is perceived differently by consumers, marketers and chemists. As formulators, we know that natural materials are sometimes, but not always, beneficial. They can have unpleasant side effects or can even be dangerous. For marketers, the concept of natural is often used generically to convince consumers of the inherent “goodness” of a product. For consumers, the words “natural,” “organic” and “eco-friendly” are interchangeable and imply that the product is safer, healthier and superior. There are no global standards governing the criteria for what constitutes a natural or organic product. Standards vary by country and were developed by different certification bodies, but are not backed by law. European countries have the strictest set of standards with two pan-European organic certification seals: Natrue, set up by six manufacturers from the German organic beauty industry, and Cosmos (Cosmetic Organic Standard) founded by five national certifiers: BDIH (Germany), Cosmebio and Ecocert (France), ICEA (Italy), and Soil Association (UK), which seek to define common requirements and definitions for organic and/or natural cosmetics.
Although details vary, the aim is to use a high proportion of organic ingredients, natural ingredients or chemically processed natural ingredients. Restrictions are in place regarding the types of chemical processes that may be used. Animal testing, synthetic ingredients (except for certain nature-identical preservatives), petrochemicals or derivatives or GMO-engineered ingredients, are all prohibited. When natural or organic certification is required, the limited choice of approved ingredients presents a new set of challenges for the formulator. Long-term stability, safety, aesthetics and user experience all need to be taken into account when selecting raw materials.
The use of petrochemicals, such as mineral oil and petrolatum, is common across a range of cosmetic and personal care products. Well tolerated, almost odor-free and colorless, they are noted for their non-reactivity, purity and inertness, along with excellent solvency and emolliency. Nevertheless, they are energy intensive to produce and contribute to the depletion of finite resources, which means non-compliance with natural or organic certification standards.
Vegetable oils and natural esters are frequently chosen as sustainable, eco-friendly replacements for mineral oils and synthetic esters in cosmetic products, but not all offer the same performance and results. Some are highly sensitive to oxidation and have a limited shelf life during storage and in the final application. Below are some of the criteria for selection and how to overcome some of the challenges associated with their use.
What’s in a Name?
Ingredients with the same INCI name do not always represent the same aspects of quality, stability and cosmetic usability. For example, canola oil can represent a variety of different chemistries, depending on where the plant is sourced and how the oil is extracted and refined. The extract can range from a food-grade, yellow-colored, strong smelling oil to a transparent, odorless oil with excellent cosmetic benefits. See table above showing oxidation development at 20°C between two types of canola oil.
Made from high-quality, locally grown rapeseed oil, using mild and efficient processes with lower greenhouse gas emissions and environmental impact than those used for synthetic emollients, Lipex Bassol C (INCI name: Olus oil or Canola oil) with its long-term lubricity makes an excellent alternative to low-spreading mineral oils. With a neutral fragrance and transparent appearance enabling a high concentration of the ingredient in formulations without affecting final color or scent, some of the typical challenges associated with natural vegetable oils, such as oxidative deterioration, unpleasant odors and reduced sensorial quality, are immediately overcome.
When sourcing vegetable oils for cosmetic use, always request a detailed breakdown of the composition and compare samples and chemical analyses from at least three variants before making a final choice. Although specialty cosmetic grade plant oils carry a higher price tag, they can be more efficient in the long-term, negating the need for antioxidant stabilizers and other additives. Not only is the raw material itself superior but also the final product is safer, more stable with good sensorial properties and the functionality expected from cosmetics, such as improved skin condition and appearance. Use of poor quality raw materials can result in adverse effects on the skin, decreasing barrier functions and impacting negatively on a healthy appearance.
Stabilizing Vegetable Oils
Adding antioxidants to the raw material will help improve stability and shelf life. It is more effective to add antioxidants to the freshly refined oil than to the formulation and important to differentiate between antioxidants added to improve stability of the oil and those added for cosmetic benefits.
For example, some of the most well known antioxidants are tocopherols, which comes in many forms, including derivatives. Tocopherol acetate is commonly used in skin creams. However, it’s important to note that it does not have any antioxidant activity in the formulation itself. This only occurs once it is absorbed into the skin and the acetate is gradually cleaved, releasing free tocopherol and providing skin with protection against free radical damage. To reduce oxidation within the formulation, it’s advised to choose antioxidants that would be present in water and oil phases as well as hooked on interphases.
Enhancing Sensory Appeal
Replicating the sensory characteristics of petrochemicals when using natural vegetable oils can still represent a creative challenge for formulators, but the sophistication of some of the refined natural oils on the market is making this a real possibility in skin care. Whereas achieving the same aesthetics offered by silicones using only natural certified ingredients, particularly in relation to hair care products, is still demanding. The addition of modified starches and biopolymers, such as sclerotium gum, to natural formulations can help reduce tackiness and give a smoother, silkier skin feel, mimicking the slip and glide achieved with synthetics. Sustainable alternatives to volatile silicones, such as plant-sourced alkanes, can also enhance aesthetic feel.
Technology is constantly advancing, enabling formulators to take all the benefits of natural ingredients without the associated disadvantages such as stability, compatibility or reduced aesthetics. Manufacturers of certified natural, sustainable ingredients are becoming increasingly creative with textures, sensory profiles and applications. AAK has extensive experience in this field and offers knowledge sharing and technical training support to customers.
AAK Personal Care
Jarek Tabor is part of the innovation and technical support team at AAK Personal Care and a member of AAK PC. He has over 19 years of experience within the cosmetics industry, focusing on the development of consumer cosmetic products and the distribution of cosmetic raw materials. He holds an MSc Eng in Agricultural Science with a speciality in biotechnology from the Agricultural University in Poznan. More info: www.aakpersonalcare.com, firstname.lastname@example.org