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Shelf Life: The Future of Preservatives

Nancy Jeffries

The industry may be in for further evaluation, as well as increased costs, as the new Registration, Evaluation and Authorization of Chemicals (REACH) protocol is having repercussions throughout the industry.

Personal care products must be functional, aesthetically pleasing and safe. Particularly when it comes to formulations to be used directly on skin, consumers don’t want to be faced with products that have separated, have broken down, or possibly could contain bacteria or mold. While consumers consistently find a wide variety of choices, with a tantalizing array of descriptive marketing terminology, they increasingly are looking for products that are functional, not frivolous. To protect the integrity of cosmetics and toiletries, and ensure consumer safety, products must be supported by an effective preservative system. Formulators know they need to preserve products to ensure product safety and be in compliance with the U.S. FDA, EU and other international regulations.

“There are several new mixtures of existing preservatives on the market today, but no new preservatives per se,” said David Steinberg, president, Steinberg & Associates, Inc., and the author of Preservatives for Cosmetics, copyright 2006, Allured Publishing. Steinberg notes, however, that there is a bigger issue at the root of the discussion. He says one critical aspect surrounding the question of preservatives for skin care and beyond is the consumer perception of preservatives in general. “There have been repeated attacks on preservatives by environmental groups and non-governmental organizations that, for a variety of reasons, have caused some controversy in this area,” says Steinberg.

All too often, according to Steinberg, the press gets hold of “bad science,” and this causes companies to reformulate. How often do consumers see “paraben-free” or “chemical-free” listed on the labels of their skin care products?

“The terminology alone suggests that the absence of parabens is something positive,” says Steinberg. That begs the question—are parabens dangerous? The answer, according to Steinberg, is parabens are safe. “They have been used since the 1920s, and their injury incidence is almost nil.” The industry is trying to unite to emphasize the safety of parabens and counter the impression that something is wrong with them.

Another aspect of the equation is the potential for the use of parabens and other preservatives outside of the United States. Right now, says Steinberg, unlike the EU and Japan, the U.S. doesn’t have a pre-approval process for preservatives. This is an area that can be quite costly, and in order to satisfy the criteria of the EU and Japan, companies may be faced with the prospect of spending a quarter of a million dollars for safety testing, costs that may not be supported by actual sales. “How do you justify spending one quarter of a million dollars for safety testing for $50,000 worth of sales?” asks Steinberg. Thus, the task of formulators is made more difficult when it is suggested they use universally acceptable ingredients (those permitted in Japan, the EU and Canada) or that the ingredients be natural or preservative-free.

Approval data varies, depending on the regulatory bodies in different areas. In the U.S., the FDA does not approve preservatives. It does, however, restrict or prohibit certain preservatives, which are noted on its negative list. The Cosmetic Ingredient Review has evaluated many preservatives, and currently rates them as safe up to a maximum concentration. The EU, which pre-approves preservatives, works on a positive list known as Annex VI of Preservatives Which Cosmetic Products May Contain—its Cosmetic Directive. There are currently 56 permitted preservatives. However, Steinberg notes that while the EU is looking at the safety of parabens, it is possible that it may de-list the longer C-3 and C-4 chain lengths, largely because it might be “too expensive to do the testing in relation to the business available.”

Steinberg believes that negative pre-conceptions about preservatives will translate into more pressure for cosmetic pre-approval and, ultimately, have a negative impact on the preservative industry. “How can you keep cosmetics without preservatives?” he asks. “You’ll have mold and bacteria.”

Ideal Antimicrobial Agents

According to Steinberg in his recent book Preservatives for Cosmetics, the ideal preservative does not exist and probably cannot exist, which is why combinations of preservatives are used. However, the ideal preservative or system will have broad-spectrum activity, enabling it to:

  • kill all types of micro-organisms,
  • be effective at low concentrations,
  • be water- or oil-insoluble,
  • be stable under all temperature and pH conditions,
  • be colorless and odorless, and not react with other ingredients to form colors or odor,
  • be compatible with other ingredients and not alter ingredient effectiveness,
  • retain shelf life activity for the intended life of the cosmetic, and
  • be safe to use.

In addition, preservatives should be easy to analyze for antimicrobial activity, easy-to-handle and inactivate, which could then be incorporated into the plates to prevent further activity or carry over. Ultimately, the preservative should be affordable and effective.

“What is really important is finding the preservative system that works and is safe,” says Steinberg. “Cost should always be secondary to these two items. The cost of a recall and the damage to a company’s reputation is too high a price to pay for an inexpensive preservative that fails.”

Preservatives and Compliance

Rohm and Haas Company discussed recent breakthroughs in the skin preservative area, citing Neolone™, in particular. According to Bill Mahoney, market manager, North American Preservatives, Rohm and Haas, the company recently has secured approvals in both Japan and Europe for the preservative for use in the personal care market. “The health and safety requirements set forth by these regulatory authorities are rigorous,” says Mahoney. “And we are proud that our product has met these standards.” The preservative also is allowed for use in 18 other countries, including the United States. “It was important for Rohm and Haas to secure these key approvals because the market is looking for global solutions and greater choice for their skin care products,” says Mahoney, noting that the company offers both a single preservative and preservative systems.

According to Mahoney, a preservative system must be robust enough to fight common bacteria and be stable over a wide range of pHs, making it compatible with a broad range of other skin care raw materials.

For a cosmetic manufacturer, brand reputation is critical, so at the end of the day, reliability and safety are of paramount concern. “Personal care manufacturers need to know their product is protected’ and that they can count on their preservative to work the same way every time,” says Mahoney.

Synergistic Systems

Preservative systems are becoming more innovative. “Many in the personal care industry have an interest in reducing their reliance on traditional preservatives,” says Mary Clarke, sales development director, Uniqema. “This is leading formulators to explore new options in the area of product preservation. One approach that is receiving significant attention centers on preservative enhancement, whereby ingredients such as Arlasilk™ Phospholipid PTM can serve to boost the effect of traditional preservatives.

“In Europe, where new regulations have established limits on the use-level of select preservatives, a need has become apparent for a preservative booster with application in a large spectrum of personal care products, including deodorants,” says Clarke.

Products such as Uniqema’s allow formulators to build in preservative enhancement effects along with a range of functional effects, such as good sensory properties, co-emulsification and cleansing in an ingredient identified as a phospholipid on the label.

“The move toward more natural products has some looking with a new eye at the levels of traditional preservatives required to achieve a suitably preserved system,” notes Clarke. Skin care emulsions, for example, now contain higher levels of natural ingredients than in the past. This often presents formulators with the added challenge of preserving difficult-to-preserve ingredients. According to Uniqema, tests have indicated that its product may offer substantial enhancement in difficult to preserve systems, even when traditional preservatives displayed very weak activity against fungal organisms.

Ciba® Tinosan® SDC is an antimicrobial preservative based on a water-soluble silver complex that, according to Ciba Specialty Chemicals, is particularly conducive for antimicrobial skin care formulations.

“(The product) corrects the previous problems with silver preservatives in that in most cases it does not precipitate or discolor,” says Ellen Werner, marketing manager, Personal Care NAFTA, Home and Personal Care Segment, Ciba Specialty Chemicals. “Because it is comprised of silver, citric acid and water, it is a natural preservative.”

Symrise offers an additional solution with Symdiol 68 and Hydrolite-5. These are not preservatives per se, but moisturizers with antimicrobial activity. “Hence, they could be used primarily as moisturizers with a secondary benefit of preservative boosting,” Ravi Pillai, global product manager, Active Ingredients, Sensory Ingredients Division, Symrise, “In fact, Hydrolite-5 is really a multifunctional active—moisturizer, antimicrobial, solubilizer, and emulsion stabilizer.” Pillai states that when used at low levels of 0.3–1.0%, Symdiol 68 helps to lower the concentration of preservatives such as parabens and formaldehyde-donors used in formulations. At higher levels of more than 1.0%, Symdiol 68 could be used to make self-preserving formulations. “These are not ‘preservatives,’ but they help reduce or eliminate preservatives which are under negative press—parabens, formaldehyde-donors or phenoxyethanol,” says Pillai.

Future Evaluation

Clearly, product safety and the environment are two extremely important issues, and ingredients must always be monitored carefully. However, the industry may be in for further evaluation, as well as increased costs, as the new Registration, Evaluation and Authorization of Chemicals (REACH) protocol is having repercussions throughout this increasingly global industry. REACH, which originated in Europe, is calling for a re-evaluation of all chemicals. Though it hasn’t been approved yet, Steinberg believes it will be, which then will require all of personal care and cosmetic products to undergo testing.

“It will affect every single chemical,” says Steinberg, noting that this means every ingredient in every cosmetic product sold in Europe whether a company manufactures an ingredient or imports it, must abide by this protocol. Steinberg predicts that REACH will be passed next year, and probably will go into effect in 2009 or 2010. Coming from a regulatory body in Europe, akin to the U.S. Environmental Protection Agency (EPA), it is giving formulators and manufacturers pause for thought, as it will require testing as well as economic consideration.

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