Restrictions on cosmetic preservatives ramp up

It has been a slow war of attrition. For the past decade, environmental groups have called out a growing number of cosmetic preservatives as suspected endocrine disruptors, cancer-causing agents, and skin irritants. Regulators have examined the claims and in some cases enacted restrictions on widely used preservatives.

Now the list of useful preservatives is down to a handful, say cosmetic formulators and suppliers. And because of the high cost of developing new preservatives and strictures against animal testing, few qualified alternatives are in the offing.

Without a preservative, often used at less than 1%, skin creams, makeup, and shampoos can become contaminated with mold, fungi, and bacteria. Some contaminants can spoil the appearance and smell of cosmetics. Others can lead to skin, scalp, and eye infections, or even worse.

Bad actors include Staphylococcus aureus, a gram-positive bacteria that can cause skin infections, and Escherichia coli, a gram-negative bacteria that can cause stomach cramps and diarrhea when people share cosmetics. “Consumers assume that preservatives are bad without understanding how necessary they are,” says Janet Blaschke, chief executive officer of the consulting firm International Cosmetics & Regulatory Specialists.

Preservatives are meant “to keep cosmetics safe throughout their useful life from production until the last bit is used at the bottom of the jar,” Blaschke says. She fears that, over time, bacteria will build up resistance to the diminishing number of options now available. She doesn’t see alternatives such as single-use or aseptic packaging as realistic—both because of the additional cost and because of the increased packaging waste.

When it comes to preservatives, the most important regulator is the European Union. The EU has a list of allowable preservatives, known as Annex V, that not only governs preservative use in the 28-nation alliance but also influences regulations in many other countries. Although the list contains more than 50 approved ingredients, often only two or three options are appropriate for a particular formulation, formulators and preservative suppliers say.

Among the preservatives European authorities have restricted are methylisothiazolinone and the mixture of methylisothiazolinone and methylchloroisothiazolinone for use in cosmetics, such as lotions, that remain on the skin. The restrictions, effective earlier this year for the combination and in 2017 for the single ingredient, were widely expected. Most everyone, including their maker, Dow Chemical, agreed the ingredients can irritate skin.

An unfavorable review by the Scientific Committee on Consumer Safety (SCCS), an EU panel of experts, judged one widely used preservative, poly(hexamethylene) biguanide hydrochloride (PHMB), not safe for use at a maximum concentration of 0.3% because of cancer concerns. SCCS is now considering whether PHMB is safe for use at concentrations of up to 0.1%, says PHMB maker Lonza. That opinion is expected in December.

Insiders also say EU authorities may soon ban chloroacetamide. French authorities banned it in 2012, but it still appears on the Annex V list of allowable preservatives. The U.S. Cosmetic Ingredient Review, a government-sanctioned industry organization, determined in 1991 that the ingredient is “a potential human sensitizer” and thus not safe for cosmetic use.

EU authorities have examined other preservatives on Annex V and found them acceptable but sometimes at reduced allowable use levels. The widely used preservative phenoxyethanol received a clean bill of health earlier this year. In 2015, phenylphenol got a passing grade but at reduced use levels. SCCS said it did not have enough data to judge safe use of sodium o-phenylphenate and potassium o-phenylphenate.

A 2013 SCCS review of parabens, compounds the advocacy organization Environmental Working Group has targeted as endocrine system disruptors, found they were safe to use. SCCS did recommend new, lower concentration limits for propylparaben and butylparaben, both of which it judged to have “a weak endocrine-modifying potential.”

Rob Taalman, director of research and science at Cosmetics Europe, which represents European cosmetics makers, says the parabens recommendation reflects the EU’s risk-based assessment process for cosmetic ingredients. An ingredient “may have an intrinsic undesirable property, but EU authorities don’t automatically ban it,” he says. Preservatives are used in cosmetics to ensure public safety, he notes.

Yet for companies, a government stamp of approval isn’t always enough. Following criticism from outside groups, some consumer product formulators have banned what they consider chemicals of concern. For example, Johnson & Johnson removed formaldehyde-releasing preservatives, which might evoke an allergic response, from all its products. It also removed parabens from baby products.

Andrea Mitarotonda, chief scientific officer of Neal’s Yard Remedies, a U.K.-based cosmetics retailer and formulator, notes that any suspicion, even if undeserved, can prompt corporate action. Without waiting for the outcome of an investigation, companies often reformulate entire ranges of products so they don’t have to face “the detrimental consequence of a possible ban later,” he explains.

Questioning old standby preservatives is not necessarily a bad thing, Mitarotonda observes. “What was considered safe 20 years ago, tested using methods and protocols available at that time, needs to be reviewed in light of the knowledge and technologies available now,” he says.

Neal’s Yard Remedies draws on the ingredients from the Annex V list, but Mitarotonda is also interested in using them in combination with natural alternatives not on the list. “Very few formulators will be aware of the chemistry of essential oils or plant extracts, which is obviously a shame as they may be missing out on opportunities to use substances to enhance the preservation profile of their products.”

Some industry players are leery of essential oils and plant extracts, which are often called “nonpreservative preservatives.” Oils and extracts can vary in quality and consistency, notes David Steinberg, a cosmetic formulation consultant. “How do you guarantee the purity of extracts compared with the purity of synthetic preservatives like parabens?” he asks.

Steinberg also wonders about the efficacy of alternative preservatives, noting that they don’t have the long history of use and characterization that backs the traditional sort. Recalls of contaminated cosmetics are dwarfed by those of clothing, toys, and other consumer products on the EU’s Rapid Alert recall database, he says. But he notes a subtle rise in cosmetic recalls in the past few years, which he attributes to lower levels of effective preservatives and the use of alternatives.

Some products that are primarily added as emollients or conditioners, for instance, can also have preservative qualities, notes Rick Strittmatter, global microbial control R&D director at Dow. Like plant extracts, they also fall into the category of nonpreservative preservatives and “can clearly play a preservation role,” he says.

But the assessment of such preservatives “also must be subject to the same risk-based approach that traditional preservatives have been subject to,” Strittmatter says. “If it is being used as a preservative, it needs to be assessed on a level playing field.”

Companies are pursuing all preservative options to combat the shrinking arsenal of traditional products. Niall D’Arcy, project manager for the Ireland-based consulting firm Biocide Information, sees a business opportunity because the new products are generally more expensive than parabens and other traditional ingredients. He says the $1 billion-a-year global market for preservatives of all types is growing 4 to 5% annually.

Of the more than 50 preservatives listed on Annex V, only about one-third are in regular use, says Andrea Wingenfeld, a technical marketing manager at the specialty chemical maker Ashland. Temperature sensitivity, pH sensitivity, and antimicrobial activity all play a role in the choice a formulator makes. In addition, formulators may avoid using a preservative approved in Europe or other regions if that preservative has been the subject of negative publicity, she says.

For leave-on products such as sunblock or makeup, the choice of preservatives is especially limited, Wingenfeld says. Since the bans on use of isothiazolinones, formulators rely mostly on phenoxyethanol, benzyl alcohol, and organic acids, she notes.

Although they do not like the attacks on what they view as beneficial ingredients, preservative suppliers acknowledge market realities. Lonza, for instance, just revamped its FormulaProtect online preservative selector tool, which allows users to avoid controversial products such as formaldehyde donors and instead choose “less controversial products,” says Phil Hindley, Lonza Consumer Care’s global marketing head for preservation.

Lonza is also interested in developing new preservatives that are acceptable to regulators, formulators, and environmental groups. Hindley says he is open to working with all stakeholders to develop such alternatives (see sidebar). But only a “robust solution” with performance, safety, and cost benefits will work in the long run, he says.

Other challenges to the development of new preservatives are the time, cost, and effort required to win regulatory approval. Ashland’s Wingenfeld says it took eight years from the time authorities received a dossier on the most recent addition to Annex V, citric acid/silver citrate, until it appeared in 2014. Given that timetable, “most companies will not see a business case in commercializing new preservatives,” she says.

The ban on animal testing for cosmetics, in place in Europe since 2009, makes it difficult for developers to submit required safety data on a new preservative, Wingenfeld adds. Cosmetics Europe’s Taalman says member companies are working with regulators to qualify new skin exposure and risk-assessment models.

However, at the moment, it’s not easy to qualify a new preservative, Taalman says. “We are basically stuck,” he says, at least until new testing protocols are approved, and that is at least a few years off.

Cosmetic products today are by and large safe, Blaschke, the consultant, emphasizes. By worrying about preservative options now, formulators and suppliers “are trying to keep up their good record,” she says, and keep crises from occurring down the road. 

CORRECTION: This story was updated on Dec. 7 to indicate that the Scientific Committee on Consumer Safety unfavorably reviewed poly(hexamethylene) biguanide hydrochloride because of cancer concerns only.