Editor’s note: This article is an update on preservative use in cosmetics in the United States and Canada through 2014. It also includes data from 2010 and 2007 for comparative purposes.
It has been four years since I reviewed the preservatives being used in cosmetics. Since then, continuing attacks against most preservatives have kept formulators scrambling to find something that will not bring forth the dreaded “free-of” or “free-from” label claim, as demanded by marketing.
Perhaps the most important and powerful attack was against quaternium-15 and its use in baby products.1 Also vilified were methylisothiazolinone (MIT)2 and its chloro derivative; triclosan;3 all formaldehyde releasers;4 and of course, the nongovernmental organizations’ favorite culprit—and marketing’s favorite for “free-from” claims—parabens.5 It seems that virtually all preservatives used in cosmetic formulas are found to be “bad” in some way.
The industry has seen regulatory action in the European Union (EU) in terms of proposed changes to and/or the removal of approved preservatives on Annex V. The EU now prohibits isopropylparaben and isobutylparaben as well as benzylparaben6—which has no reported uses in the United States. Interestingly, this prohibition was not a safety issue but an economic issue since the testing requested was far more expensive than the total sales of the iso-parabens. These preservatives really should be listed as “not supported” rather than prohibited, which implies they are not safe.
Quaternium-15 is also being proposed for removal from Annex V,7 again for the lack of support by manufacturers. There is a proposed limit of 15 ppm MIT in both rinse-off and leave-on products,6 and polyaminopropyl biguanide was found as “unsafe” by the Scientific Committee on Consumer Safety (SCCS) in the EU as a CMR under REACH.8 In addition, France has requested that phenoxyethanol be restricted to a 0.4% maximum for products intended for children under three years, and prohibited in diaper/nappy areas.9
In the United States, the State of Minnesota initially passed law HF 458 prohibiting the use of formaldehyde or formaldehyde-releasing compounds from being used in all products intended for children eight years or younger.10 Further, it specified that these compounds cannot be replaced with chemicals known or suspected to be toxic to development; to cause cancer, genetic damage or reproductive harm; to disrupt endocrine or hormone systems; or to damage the nervous system, immune system or cause systemic toxicity. (While they were at it, they might as well have included “causes obesity, temper tantrums, headaches, cramps, smoking, drinking alcohol…,” which, of course, they do not).
Manufacturers quickly discovered they no longer could preserve wet wipes, cleansing products or shampoos, so the state allowed formaldehyde releasers back under given conditions. It is now specified that if a chemical is an intentionally added ingredient that degrades under normal conditions of temperature and pressure to release “free” formaldehyde, it is prohibited if the level is above 0.05%. The state also banned triclosan from any children’s products not approved by the U.S. Food and Drug Administration (FDA).11
Both of these cases reflect ignorance on the part of legislators. For one, they never defined a method for determining free formaldehyde levels. They also do not appear to know the only cosmetic use of triclosan is in underarm deodorants—and children eight years of age or under are not likely to use deodorant.
One could go on and on about the myths perpetuated by activists who “hate” (and misunderstand) preservatives. For example, there is a belief that benzoic acid reacts with citric acid or ascorbic acid to form benzene. While it has been more than 50 years since I taught organic chemistry in college, I still cannot figure out how two acids could react to form a hydrocarbon.
And take parabens, again, which have been accused of causing breast cancer, decreasing sperm production and being endocrine disrupters. None of these is valid when all the facts are considered. However, a “toxic trio” of: activists not concerned about the facts; gullible reporters who love sensationalism; and cosmetic marketers willing to say anything to sell more products creates an environment with the potential to destroy the most common and safest of preservative options formulators have.
Regarding France’s opposition on phenoxyethanol, it started as “guilt by association.” Phenoxyethanol is made by reacting 1 mole of ethylene oxide on phenol. And since 1-mole ethoxylates of short chained alcohols like methanol and ethanol make highly toxic solvents—not used in cosmetics—the belief remains that all 1-mole ethoxylates are “bad.”
Another popular preservative under attack by the same flawed logic is caprylyl glycol. Here, the argument is that “glycol”—which is the INCI name for ethylene glycol, also known as antifreeze for cars—is a 1,2 diol. And since ethylene glycol is extremely toxic, caprylyl glycol must be, too.
Impact on Preservative Use
What has been the impact of these attacks? Table 1 gives some indication, comparing numbers from the last report, in 2010,12 with today’s. These numbers include the FDA’s data from its voluntary reporting of cosmetics (VCRP) program, along with numbers from Health Canada, which has a mandatory notification of all cosmetic ingredients. They are listed in descending order, based on U.S. 2014 data.
Several important observations are clear. First of all, only one-third of the formulations registered in Canada are also registered in the United States; a really dismal result. This explains why different bills in Congress are calling for mandatory registration.
Methylparaben use in the United States grew slightly from 2010 to 2014, appearing now in 28.5% of reported formulations, but dropping significantly in Canada, with only 5.8% of formulas using it.
Phenoxyethanol use was reported in 26.9% of U.S. formulations in 2014, up from 24.1% in 2010, while in Canada it was 17.0% in 2014. Clearly, this is becoming a critical preservative.
Caprylyl glycol, frequently sold in combination with phenoxyethanol, was accounted for in 7.6% of U.S. formulations—the same as in Canada. Its U.S. use doubled from 2010 to 2014.
A slight increase in use of methylisothiazolinone was reported—for now. This will undoubtedly decrease as the EU restricts its use to ineffective levels. In contrast, the use of major formaldehyde-releasing preservatives imidazolidinyl urea, diazolidinyl urea, DMDM hydantoin, sodium hydroxymethyl glycinate and quaternium-15, decreased; note this decline is based on the number of reports as a percentage of the total formulas. Iodopropynyl butylcarbamate use also is declining, mainly due to EU restrictions on use levels and prohibition in leave-on products for use over large body areas.
Finally, it is interesting to note the growth of “soft” preservative acids—e.g., benzoic acid, sorbic acid and dehydroacetic acid. This can be attributed to the growth of the “natural” cosmetic market. Also noteworthy is the growing use of solvents with limited activity, such as benzyl alcohol and ethylhexylglycerin.
All websites accessed Jan. 6, 2016.