Protecting water-based cosmetics from microbes that can cause rashes or infections has traditionally been the job of synthetic preservatives. But owing to a combination of toxicity concerns and consumer pressure, some cosmetics makers are eschewing specific preservative molecules such as parabens or formaldehyde—or avoiding synthetics entirely.
In their place, ingredient makers have come up with a variety of plant extracts and protein derivatives to preserve personal care products. However, these systems are relatively new to the market and, in one case last year, may have failed to stop microbial contamination of a sunscreen product for babies.
Pressure on marketers to reformulate away from synthetics comes from a variety of sources. Consumer-led petitions on the popular website Change.org ask retailers such as Walmart, Target, and CVS to “provide safe beauty options,” with sections in their stores offering brands free of ingredients such as parabens.
A group known as the Campaign for Safe Cosmetics targets formaldehyde donors—ingredients that release small amounts of the chemical—for elimination. It points out that the chemical causes rashes on sensitive individuals and is a known carcinogen.
Supporters of synthetic preservative chemicals point out that such molecules have a long history of safe and effective use. Still, the group succeeded in pressuring Johnson & Johnson in 2011 to agree to eliminate formaldehyde from baby products. And legislators in Minnesota banned formaldehyde donors in baby products last year.
But last year’s baby product contamination raises questions about the efficacy of so-called natural preservative systems that do not rely on any synthetic chemicals. New Hampshire-based W.S. Badger Co., a maker of natural personal care products, recalled its children’s sunscreen lotions because of microbial contamination that could have had serious health consequences.
The firm discovered during “routine retesting” that some tubes of children’s sunscreen lotions were contaminated with Pseudomonas aeruginosa, Candida parapsilosis, and Acremonium fungi, according to Rebecca Hamilton, the firm’s product development director. The lotions all passed microbiological testing prior to shipment to retailers, she adds.
When Badger discovered the contamination, Hamilton says, it voluntarily recalled all 4-oz tubes of its SPF 30 Baby Sunscreen Lotion and one lot of its 4-oz SPF 30 Kids Sunscreen Lotion. To date, it has received no reports of adverse reactions to the recalled products.
Badger notified the Food & Drug Administration, which alerted U.S. consumers to the recall. When the company notified Health Canada, the agency also alerted consumers while pointing out the potential consequences of the contaminants. They pose a heightened risk of pneumonia and other infections for people whose immune systems have been weakened by conditions such as cancer or diabetes.
For healthy people, Health Canada noted that Pseudomonas bacteria can cause local infections, abscesses, and blood infections through open cuts, lesions, and burn wounds.
Hamilton tells C&EN that the recalled products used an antimicrobial system consisting of a peptide called Leucidal Liquid plus glucono delta lactone, a plant-based additive often used as a food preservative. Leucidal Liquid is derived from the Leuconostoc bacteria family. Durant Scholz, an owner of Active Micro Technologies, the maker of Leucidal Liquid, says his firm actually supplied Badger with Arborcide OC, an antimicrobial agent also derived from Leuconostoc but functionally and compositionally distinct. C&EN could not reach Hamilton to explain the discrepancy.
The contract manufacturer that did most of the formulation and testing work on the children’s lotion checked its facilities and could not discover the source of or reason for the contamination, Hamilton says. However, Scholz says, “it is our understanding that the levels of Arborcide OC used were well below what we recommended.”
Hamilton says Badger has switched to another contract manufacturer and is reformulating the product. Badger, she says, won’t release another water-based children’s sunscreen “if it can’t meet our rigorous standards.”
The company makes other baby and sunscreen creams, but like its other personal care products, they do not contain water, Hamilton says. Instead those products use carriers such as sunflower oil and beeswax, which do not need preservatives, she says. Those products do contain vitamin E to keep oils from going rancid.
In formulating new water-based sunscreen lotions, Badger is considering using Leucidal Liquid as well as other plant-based preservative systems including Biovert, a combination of glucose, lactoperoxidase, and glucose oxidase made by Lonza, a chemical firm. Badger is not, however, considering more traditional preservatives, Hamilton says. “Our customers only want natural ingredients, which means no petroleum-based preservatives.”
Badger wouldn’t have had to recall its children’s sunscreen lotion if it had used the traditional synthetic preservatives, according to David C. Steinberg, a consultant on cosmetic preservatives. “Blanket condemnation of synthetic preservatives is absurd,” he adds.
In Steinberg’s opinion, FDA should have done much more than tell consumers about Badger’s recall. “FDA should have said to Badger, ‘You have a noncompliant drug manufacturing facility,’ and then shut them down.”
Marketers, rather than scientists, seem to be in charge of formulating products these days, Steinberg observes, by insisting on so-called natural ingredients. Marketers also promote misunderstanding about synthetic ingredients, when, for instance, they label personal care products as being paraben-free. Such a claim, he says, ignores the fact that both U.S. and European regulatory authorities have found little evidence that parabens cause cancer.
The war against synthetic preservatives reached Minnesota last year when legislators banned formaldehyde donors in children’s products. The ban barred retail sales of baby products containing the donors beginning in August 2015. Formaldehyde donors include molecules such as DMDM hydantoin, imidazolidinyl urea, and diazolidinyl urea.
However in mid-May, the state amended the ban to allow continued use of the donors as long as the level of formaldehyde in a product is greatly reduced. No reason was given for the change.
Steinberg applauds Minnesota’s reversal of a total ban on formaldehyde preservatives in children’s products. He points out that the amount of formaldehyde used in personal care products is not a danger to humans, although it is lethal to microbes. “The dose makes the poison,” he says.
However, Steinberg says he is angered that the original 2013 ban impugned the safety of formaldehyde donors. Despite the recent reversal, “the damage has been done,” he says. “Formaldehyde donors have always been safe.” News media covered the 2013 ban. Few if any news outlets covered the reversal.
The new Minnesota law limits formaldehyde in baby products to 0.05%, down from the 0.2% FDA currently allows in personal care products. The lower level makes formulating an effective preservative system more difficult, Steinberg says.
Manufacturers of traditional preservatives are concerned over the attacks against the synthetics. “We’re highly subjected to social media,” complains Michael Mack, business development manager of Thor Specialties, a maker of both synthetic and plant-based preservatives. “Information gets out without scientific backing, and people assume certain chemicals are bad.”
Formulating a product that effectively preserves without causing irritation is a balancing act. “You can’t just choose a preservative off the shelf,” Mack says. “You need to make sure preservatives work under actual conditions.”
Failure to effectively prevent product contamination can be catastrophic. “Preservatives are low-cost additives that make up 1% or less of a formula. But if they fail, they can ruin a billion-dollar brand,” Mack says.
Despite the challenges, preservative suppliers are increasingly offering plant-derived alternatives to synthetics. “Traditional preservatives are under attack today, and so you see more focus on nontraditional preservatives,” explains Linda B. Sedlewicz, U.S. country manager for Schülke & Mayr, a 120-year-old German maker of preservative systems. She cautions that “the nontraditional preservatives need to have effects similar to traditional types.”
Both types of preservatives can fail, Sedlewicz warns. Synthetics are known to be effective, but “use too little and a product might not be properly preserved,” she says. Sedlewicz adds that “too little experience with the newer nontraditional preservative can lead to failure as well.”