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Natural Preservative Systems: Almost 100% Natural

Synthetic preservatives are still widely used in natural products. But change is coming.

_{By Jennifer Kwok, Editor}

For companies looking to go 100% natural with their product formulas, the biggest challenge often lies in finding a natural preservative system.

Why don’t more beauty products include natural preservative systems? Simply put, there aren’t many on the market.

“It’s tricky,” says Ray Mauro, manager of product development for Origins. “When you’re working with natural preservative systems, you don’t have the palette and library that you do for synthetic preservative systems. I’d say the market is continuously looking for more natural preservative systems.”

Some experts predict more systems to be developed in the next few years—especially as national brands begin entering the natural products arena. Ironically for some of the smaller brands that have been creating their own natural preservative systems for years, it is the larger corporations that may end up spurring market development.

Many of the natural preservative systems that do exist have been pioneered by beauty brands for their products only. Their formulations may set the stage for the future of natural preservative systems.

Why Replace Synthetics?

Whether accurate or not, studies pointing to potential health risks of certain synthetic preservatives have sent companies scrambling to find natural alternatives. Parabens, so prevalent in beauty products, are now considered by many as undesirable after researchers claimed to find parabens in samples of breast tumors. “We’re trying to find things that are as effective, especially against yeast and mold, against which parabens were so effective,” says Cindy Angerhofer, director of botanical research for Aveda.

Also limiting marketers’ preservative options are natural and organic certifiers that continue to add more preservatives to their “banned” lists. Ecocert recently announced that it no longer allows phenoxyethanol. “It’s a natural compound that is usually synthetically made as an ingredient,” says Angerhofer. “But it’s nature-identical to some components that are in, for instance, rose oil. It smells great; it smells like roses. And it works well. But Ecocert has disallowed that [compound] as of January.”

Aside from the restrictions put upon them, brands have another reason to find natural preservative systems—so that they can achieve the claim of a 100%-natural product. It is a goal that only few have been able to achieve.

Challenges

_{Aubrey Organics’ Glycogen Protein Balancing shampoo and conditioner feature preservatives that are 100% natural.}

Unlike synthetic preservatives, which can often be added as the last step of product formulation, a natural preservative system must be carefully developed together with a product formula from the very beginning of formulation to ensure that all ingredients work together. “It’s a very different mind-set,” says Curt Valva, general manager of Aubrey Organics.

Industry experts are careful to include the word system when speaking about natural preservative systems. The reason is that there is no such thing as a natural preservative. “There’s no one natural preservative,” says Mauro. “Rather, it’s a system of natural ingredients that work together to preserve a product.”

“I don’t think that we’re going to find any one single magic bullet ingredient,” agrees Christine Baier, executive director of research and development for Origins. “What we have been finding, and what we’ll probably continue to find, are systems that work together.”

Often, the process of fine-tuning a natural preservative system to a product requires trial and error. Natural ingredients tend not to be as potent as synthetics, so a formulator might have to use them in higher concentrations in an effective preservative system. “We might be able to get by with 0.05% of a really good synthetic preservative, whereas we need to use 0.10 or 0.20% of a natural one, which can then throw off the viscosity, stability, and aroma of the formula. All of those things are really affected by putting in other materials,” says Angerhofer. “So yes, it’s a real challenge. You have to adjust a lot of parameters when working with natural preservative systems. It’s at least as much an art as it is a science.”

“Natural products often have a characteristic odor or color that may be undesirable,” adds Rosita Nunez, manager, commercial development, preservatives, for ingredient supplier Lonza (Allendale, NJ). “This can lead to incompatibility with other ingredients in the finished product, such as the fragrance. Natural products can be used effectively but are not drop-in replacements for existing preservatives. Some formulas might need to be reformulated.”

So What Works?

Plant extracts and phytochemicals can serve as effective antimicrobials.

Angerhofer says that Aveda continues to look at citric and malic acids that are effective at higher concentrations, as well as glycols derived from plants, not petroleum.

_{Rosemary extract, derived from the plant, makes an effective antimicrobial.}

Lakshmi Prakash, vice president of innovation and business development for ingredient supplier Sabinsa Corp. (Piscataway, NJ), says that secondary metabolites such as phenolic compounds, essential oils, and tannins in herbal extracts make effective antimicrobials. In particular, she identifies spice oils such as tumeric oil, rosemary oil, Coleus forskohlii oil (from the family of mints and lavenders), and the essential oils of cinnamon, clove, oregano, pepper, galanga, peppermint, and thyme as effective preservative ingredients, particularly when used as blends.

Also on Prakash’s list are sage, lemon balm, green tea, Kaempferia galanga, and Neem leaf extracts, as well as isolated phytochemicals such as cinnamates, benzoates, and eugenol.

Aubrey Organics’ Valva says that fragrance and flavor manufacturers are also conducting research in essential-oil isolates. “That’s where the research is going,” he says. “If you take an essential oil, say a lavender essential oil, and extract a couple of those isolates, there are some isolates that in some cases work very well as natural preservatives.”

However, says Valva, there is an issue with the odor of essential oil isolates. “They don’t smell very good,” he says. “In isolation, they don’t always smell like the original essential oil.”

“Essential oils are very good at inhibiting bacterial and fungal growth, but they are also highly aromatic,” agrees Aveda’s Angerhofer. “So it can be difficult to create your own product scent around that.”

“For optimal efficacy, most essential oils may be required in quantities that would affect the appearance or aroma of a cosmetic formulation,” adds Prakash.

Companies can find successful ways to work with essential oils as preservatives, however. Origins used a patented essential oil blend as the preservative system for its Origins Organics line and was able to achieve product scents—such as a citrus spice scent—that smell extremely good and soothing.

In addition to looking for breakthroughs in essential oil isolates, Valva says that he has been studying enzyme-based preservatives. One that Valva likes in particular is biovert, a combination of glucose oxidase and lactoperoxidase. “It really works quite well, but you do need to give it a little bit of help,” he adds. “You need to take your product a little out of that middle pH area, because it tends to work at lower pH.”

Also, adds Valva, “the best natural preservative that we’re all somewhat familiar with—and we use this in some of our products—is grain alcohol. It’s a wonderful preservative. It works at low levels to pretty much kill all germs.”

Helping Natural Preservatives Along

To improve the efficacy of a natural preservative system, formulators can adjust a product’s formula.

Reducing the amount of moisture in a formula—perhaps by creating a thicker formula that contains less water—is one way to do this. “The amount of water available for bacteria to grow in is really critical,” says Angerhofer.

Glycerin is one natural ingredient suggested to reduce the water available to microbial growth in a product. “Glycerin is a natural humectant that tends to reduce water activity,” says Angerhofer.

Glycols also reduce water activity. “There are some glycols that have traditionally been derived from natural gas or petroleum that people are now trying to derive from plants,” Angerhofer says. “Plant glycols do a good job of holding onto water and not letting the bacteria have it.”

However, Lonza’s Nunez warns, “Glycols that limit water activity of the finished product are effective but usually require a high-use level.”

Other natural additives that can help lower water activity include glucans, mannans, and “other polysaccharides extracted from commonly used culinary materials such as tamarind seed and fenugreek,” says Sabinsa’s Prakash.

Adjusting the pH level of a formula is another way to prevent bacteria growth. “Water-based products that are in those middle-range pH areas—the 6, 7, and 8 range—tend to be more biologically active. They’re more prone to having bad guys grow in them,” says Aubrey Organics’ Valva. “But if you formulate your products to have either lower or higher pH, you can help your natural preservative systems along.”

Organic acids can help adjust pH levels. Lonza’s Nunez says such acids are effective as paraben replacements. “Their activity, however, is limited to products with an acidic pH. Activity for these acids decreases exponentially as the pH increases. For finished products with pH [levels lower] than 6.5, organic acids are effective.”

Supply Base and Costs

Suppliers aren’t necessarily rushing to fill the void of natural preservative systems, simply because high-volume demand isn’t there yet. The dearth of offerings alone makes natural preservative systems more expensive.

Synthetic preservatives can also be mass-produced, making them cheaper. Even nature-identical formulas often use synthetic ingredients. “Most of the chemicals in use today are synthetic,” Nunez explains. “Some may be nature-identical, meaning that they occur in nature, but the actual chemicals being used in production are synthetic. This is because the quality of synthetic materials is more consistent, the supply is more reliable, and the cost is more attractive. Some chemicals may be derived from a natural origin but will go through processing to provide a material that can be used in cosmetic production.”

As an example, Angerhofer says, “Salicylic acid is a nature-identical substance. A lot of plants have salicylic acid, but very often, it’s too expensive to get it in that form from the plant, so it is made synthetically to be exactly the same as a natural compound.”

Another factor that raises the price for natural preservative systems is the quantity of natural ingredients required for an effective preservative system. As mentioned, because their potency is weaker, natural ingredients must be used in higher percentages than synthetics. That raises the cost of a formula. “Natural products may be more costly because the supply is limited, and processing is expensive,” says Lonza’s Nunez. “If a higher level [use] is required, the cost of the formula may be higher.”

Marketers also warn that it is also important to vet suppliers to ensure that the natural preservative systems that they offer are truly natural. “There is a continual wave of so-called natural preservatives being marketed by suppliers,” says Angerhofer. “I say ‘so-called’ because, frequently, we find that these natural preservatives are adulterated with known synthetic preservatives.” She says that a few years ago, the industry became interested in grapefruit seed extract as a preservative but ultimately found that a synthetic preservative had entered the extract on the way to suppliers.

“I have seen many things touted as natural preservatives that honestly don’t work,” says Origins’ Baier.

Are Naturals as Effective as Synthetics?

When all is said and done, are natural preservative systems as effective as synthetic preservative systems? “You’re not going to get five, six, seven years of shelf life with natural preservatives the way you might out of some of the petrochemical or synthetic, chemical-based preservatives. You’re just not going to,” says Aubrey Organics’ Valva.

But can natural preservative systems achieve a lower shelf life of, say, up to 12–24 months? Yes, say the companies interviewed, who add that if a brand is using natural preservative systems versus synthetics, there can be no trade-offs in performance.

“We don’t lower our standards because we’re using natural preservatives,” says Aveda’s Angerhofer. “For total transparency, we have not been able to formulate all the way out of synthetic preservatives yet, and I try to make sure that our consumers know that, too. We’re definitely working toward that end, but we find it’s critical that products are safe and stable. We’re definitely working and supporting research to develop new natural preservative systems. But we’re not 100% there yet.”

“We can’t give anything up,” adds Origins’ Mauro. “One of the challenges when we developed our Origins Organics line [a USDA-certified organic skin care line] was trying to find a complex system that was organic, met the USDA standards, and met the shelf life and safety standards of conventional products.”

The beauty brands that have used natural preservative systems seem to have done so successfully. However, the challenges going forward lie in market challenges—lack of development in the area of new and better natural preservative systems. “The performance and cost of these systems are still not equivalent to the traditional preservatives, so they are not widely used in marketed products,” says Lonza’s Nunez.

There may not be many choices right now, but companies are researching and making headway with their discoveries. However, “we can only do so much as a small company,” says Valva. “The problem is that unless there’s some kind of real market for natural preservative systems, an ingredient manufacturer can’t warrant the investment. It’s very expensive to develop a lot of these ingredients. But as demand continues to grow, I think that ingredient suppliers will grow with us.”

He continues, “Whenever large companies are getting involved, there’s a lot more research being done. So I really am excited. I’m positive that there are going to be some breakthroughs over the next year or two.”

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