Natural alternative discovered

COSSMA: What role do glycerine and propanediol play in the sensory performance of a formulation?

Kyle Huston: Glycerine and propanediol are categorically solvents in personal care applications, aiding with solubility and humectancy in most formulations. They can be used in a variety of personal care and cosmetic applications from skin care to hair care to colour cosmetics.

What are their disadvantages?

Like many ingredients, each can ex-hibit some pros and cons depending on the application and formulation they are being used in. Glycerine is a relatively low-cost ingredient, but it does not come without drawbacks. For instance, it can create stickiness at higher levels in a formulation and is not as valuable as an antimicrobial agent compared to other common diols.

What natural alternatives are there?

The landscape of natural solvents has evolved over the last few years with the entrance of our natural butylene gly-col¹.Conventional, petrochemical-based butylene glycol has been used ubi-quitously in everyday personal care and cosmetics for decades due to its many attributes, including enhanced skin-feel and lack of skin irritation. But for a long time, it was unable to be produced at scale from a natural source.

What processes or raw materials are used to produce them?

Conventional, petro-derived butylene glycol is derived from fossil fuels like petroleum and natural gas, but our natural butylene glycol is produced from a fermentation process (similar to making beer and wine) and sourced from renewable plant sugars. It reduces global greenhouse gases by 1.92 kg CO₂ equivalent compared to conventional production. This means the ingredient has the potential to reduce global greenhouse gases by nearly 100,000 tons per year and eliminate the use of 50,000 tons of acetaldehyde, a suspected carcinogenic and mutagenic feedstock used in conventional production methods.

What do we need to know about the biodegradability of natural butylene glycol?

Our natural butylene glycol is considered ‘readily biodegradable’. This means the ingredient will biodegrade quickly and completely (≥ 60% by OECD 301A-F/ASTM D7373 testing²) within 28 days when subjected to sunlight, water, and microbial activity. Not only is this great news for the environment but also for formulators working to create products that come with a biodegradability claim.

Can natural butylene glycol be used in certified natural cosmetics?

We use the ISO 16128 definition to help our customers differentiate their products and make claims. Using this description, our natural butylene glycol is defined as a natural ingredient with a natural index of 1. It is sourced from natural and renewable plant sugars, which by itself would classify the product as naturally derived. Additionally, we uncovered several peer-reviewed studies showing that 1,3 butylene glycol occurs naturally in superfoods like avocadoes and coconuts. This discovery enabled us to define the ingredient simply as a natural ingredient.

What impact can your natural butylene glycol have on the environmental impact of the product?

A key feature is its carbon footprint. The ingredient reduces global warming potential by more than 50% compared to petro-based butylene glycol. This can help formulators who want to reduce the carbon footprint of their prod-ucts while making a positive impact on their corporate sustai-nability goals.

What challenges do these alternatives bring with them? Can a brand ‘simply’ switch to the new ingredient in its formulation?

Reformulation requirements are dependent on the type of product being developed. While some alternatives can serve as drop-in replacements in a formulation, others may require further modification to achieve the desired results. In existing formulations using petro-based butylene glycol, the natural alternative can operate as a drop-in replacement. After testing the major attributes – solvency, antimicrobial efficacy, and skin moisturisation to name a few – we found no perceivable or statistical difference between our natural and the petroleum-based version.

In contrast, switching from a different glycol or triol like glycerine or propanediol may require additional formulation adjustments due to the differences in performance. These variances, which can be nuanced or significant, are dependent on the type of  the formulation.

What effects does butylene glycol have when used in fragrances?

Historically, butylene glycol has not been used by the fragrance industry. But given the widespread successes, we saw an opportunity to help meet consumer demand for more sustainable products without compromising the artistry and quality of their fragrances. As a new player in this market, we conducted a comprehensive, aspirational fragrance study to substantiate this supposition.

With the help of a master perfumer³, we compared our natural butylene glycol with other natural diluents and the industry standard, dipropylene glycol. More than 100 fragrance ingredients and several commercial formulations were tested. Results revealed that natural butylene  glycol presented fragrance notes  more clearly and distinctly than  the other diluents tested. Because  of the large scope of the study, we also came to understand the solubility limitations of diluents in fragrances, helping perfumers  predict which situations can  present increased organoleptic  performance.

References:

¹ Brontide natural butylene glycol

² https://www.oecd.org/chemicalsafety/risk-assessment/1948209.pdf 

³ Moca Fragrances