Why Is Biodegradability in Rheology Modifiers Important?

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If there is a single watchword permeating every aspect of the current cosmetics and personal care landscape, it is “sustainability.” As we grow more and more aware of the sometimes devastating impact of human activity on our planet and the long-term implications of environmental destruction and climate change, virtually all industries are striving to adopt more sustainable practices. Our industry is no different.

One crucial concern centers on the biodegradability of cosmetics ingredients. When an ingredient is biodegradable, it can be decomposed or broken down by natural processes without leaving harmful residue behind. Nonbiodegradable substances can take decades, centuries, or even millennia to break down, wreaking havoc in the meantime. When nonbiodegradable materials end up in landfills or bodies of water, they can cause tremendous harm to the ecosystem. 

Fortunately, as understanding increases, more and more biodegradable alternatives are becoming available, offering the same or similar properties as their nonbiodegradable counterparts without the environmental impact. 

In today’s post, we will look at one cosmetics industry sustainability advancement that has advanced in leaps and bounds in recent years: biodegradability in rheology modifiers. 

Where Are Rheology Modifiers Used in Cosmetics?

Rheology is the physics of the deformation and flow of materials (solids, liquids, and gases) and how those materials respond when force or stress is applied to them. These responses are referred to as a material’s rheological properties. 

Rheology has many different applications across various fields, including ours. Rheological properties, such as viscosity, are vital in the formulation of many of the cosmetic and personal care products we all use every day. 

Rheology modifiers are substances that alter the rheological properties of a given material, and they’re added to cosmetic formulations to create the desired characteristics (e.g., the appropriate level of viscosity and how the completed formulation feels on the skin). They are often colloquially referred to as thickeners.

Rheology modifiers appear in all kinds of personal care and hair care products as well as color cosmetics—in other words, any product in which thickness, viscosity, and response to pressure are important. 

You can read more about rheology modifiers on our blog and check out the market-leading cosmetics ingredients we offer, including our G-GEL, OleoFLEX, and SENSOGEL rheology modifiers. 

How Does Biodegradability Factor Into Cosmetic Formulations?

As we mentioned above, biodegradability is becoming an increasingly important consideration in selecting ingredients for cosmetics. The use of biodegradable materials can reduce waste, minimizing the industry’s environmental impact and protecting our planet. 

In addition, consumers are becoming more and more selective about the products they will use, with environmental factors playing a key role in purchasing choices. Therefore, it also makes good business sense to stay ahead of the curve in formulating your cosmetics products. It is likely that, in the coming years, we will see more legislation requiring the use of environmentally friendly ingredients across the United States and the world.

However, biodegradability is not the sole factor in making decisions about which ingredients to use in your formulations. Numerous other considerations, including ingredient safety, efficacy, and consumer appeal, must also be taken into account. 

Why Are Biodegradable Rheology Modifiers Important, and What Are the Challenges in Introducing Them?

Historically, rheology modifiers have typically not been biodegradable. This is because they were created before environmental factors played a crucial role in our industry, and when efficiency and functionality were the dominant concerns. This means companies used those products that were most available, which were typically synthetic-based rheology modifiers. 

Acrylate polymer thickeners are ubiquitous throughout the cosmetics and personal care industry because they’re cheap and easy to use. However, sustainable and clean beauty brands are now beginning to include these ingredients on their “no-go” lists, creating an urgent need to replace them with something greener. Ethoxylated thickeners are also popular and difficult to replace due to the highly specific ways in which they interact with other ingredients. 

The challenge facing manufacturers now is to replicate the functionality of these older ingredientsusing those from natural and nonharmful sources. Xanthan gum and carrageenan gum are two commonly used natural rheology modifiers. However, these natural thickeners tend to be stickier than their synthetic counterparts and may not flow as well under pressure (such as when the product is squeezed from a bottle).

This all means it’s still difficult to create a 100% natural product that fully mimics those using the synthetic ingredients that have been on the market for decades. 

The Science of Rheology Modifier Biodegradability So Far 

Polyethoxylated linear polymers below a certain weight threshold are fairly biodegradable. However, once you begin to create and use larger polymers, they become more hydrophobic, which reduces the overall biodegradability. Many of these materials will eventually biodegrade, but the speed of biodegradation matters, particularly when a product will be manufactured and used in mass quantities, in order to ensure they do not bioaccumulate in the environment. 

Creating a rheology modifier that breaks down quickly will complete the chain of sustainability in the cosmetics industry, and many manufacturers are working to reach this goal. 

We’ve tested some of the commercial alternatives currently on the market, making direct comparisons to our own products, and have found they are slow to biodegrade. That’s why we developed Sorbithix L-100, a highly effective thickener capable of thickening systems that others on the market struggled with. Sorbithix L-100 may also be capable of replacing acrylates (carbon-based backbone materials that are slow to break down) due to its extreme efficacy and fast biodegradation. 

What Does the Future Hold for Advancements in Rheology Modifier Biodegradability?

There have been many exciting developments in this field in recent years, and the technology continues to improve. 

So far, no company has successfully created a completely sustainable and biodegradable acrylate thickener. However, ways to make ethoxylated materials more sustainable have been discovered, for example, by utilizing 100% naturally sourced ethylene oxide. This paves the way for the creation of an ethoxylated rheology modifier that is both biodegradable and sustainable according to internationally accepted standards.

We believe these developments will soon enable the industry to use rheology modifiers that are ultimately biodegradable and perhaps eventually even readily biodegradable. These are likely to become more widely available in the next three to five years. 

However, the industry also has work to do in the area of consumer perception around these ingredients, which end users may view with suspicion. This is largely due to the industry’s history of using processing methods that leave behind residual contaminants known to be carcinogenic. Manufacturers must implement processes to ensure the elimination of these contaminants as well as educate consumers on the safety of properly made ethoxylated products. 

The state of New York has already mandated that wash-off formulations must show they do not contain this harmful residue above a certain level to be legally sold. We expect that many other jurisdictions will follow with similar legislation in the next few years. 

Consumers are also concerned that ingredients with a low molecular weight allow for some skin penetration, potentially bringing other harmful particulates into the body with them. There is a balancing act to be done here: making the molecular weight large enough to mitigate this problem and small enough to remain biodegradable. 

We believe our industry is fully capable of creating and adopting rheology modifiers that are both entirely sustainable and safe, and that, when we do, it will represent a huge step forward for the industry as a whole. 

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We are tremendously proud to have developed an associative thickener that we believe to be 100% biodegradable—something that no other manufacturer has yet achieved and which brings the industry closer than ever to having access to a completely sustainable rheology modifier. We hope to bring this completed to market within the next few months. 

In the meantime, if you would like to learn more about anything we have covered in this post or about any of our products, please feel free to contact us. We will be pleased to answer your questions, provide samples, and support you in any way we can.

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