2010 Frequency of Preservative Use

Editor’s note: This article is an update to the October 2008 article¹ reporting the frequency with which preservatives were being used in personal care products. The previous report was based on formulations registered with the US Food and Drug Administration (FDA) and, for the first time, with Health Canada. The present report is also based on data collected for preservatives used in personal care in both the United States and Canada.

Since the last time the frequency of preservative use in cosmetics was reported,¹ several events have taken place that impact the use of preservatives. The first was the Personal Care Products Council’s (PCPC) strong suggestion for member companies to participate in the FDA’s Voluntary Cosmetic Registration Program (VCRP) as part of its Consumer Commitment Code. This resulted in an increase in the number of formulations registered—from 27,771 to 36,811.

In addition, about two years ago, the FDA enacted a major program to delete obsolete formulas from its database that included raw materials no longer used in the United States. This resulted in the removal of preservatives such as chloroacetamide from the list. As many formulators know, the appearance of those obsolete raw materials in the FDA’s database have been used by non-governmental organizations (NGOs), especially in California, to attack the industry since some of these materials were found unsafe by the Cosmetic Ingredient Review (CIR) expert panel; and although these materials were not in use, they were still listed in the database. Finally, the industry has gone through three years of reformulating products to omit preservatives labeled “bad” by NGOs, such as parabens, although they have been found safe by the CIR expert panel.

US and Canadian Preservative Use

Table 1 compares the frequency of preservative use in 2007 to 2010, as reported to the FDA and Health Canada. Several preservatives and their salts are listed as one entry since the acid is the active form and the salt is the easy way to incorporate it into a formulation. The pH of the formula is adjusted, then the salt is converted in situ to the active form.

There have been some major deletions since the 2007 report. First, sodium iodate, phenyl mercury acetate, nisin and halocarbon were removed by this author since there have been no reported uses of these materials in more than 10 years. Other raw materials removed include boric acid/sodium borate, which is used in emulsions as neutralizers; formaldehyde and paraformaldehyde, used for nail hardeners; and resorcinol, which is used in hair dyes. In addition, salicylic acid was removed, which is used as an exfoliant; the reducing agent sodium sulfite/sodium bisulfite; and thymol, an essential oil used for fragrance.

Based on the general assumption that the ratio of use translates to total numbers, and that Health Canada deletes obsolete notifications, it is easy to see that only about 25% of the formulations in the United States are registered under the voluntary VCRP system, compared with three times the amount registered with Health Canada.

Preservatives on the Upswing

Surprisingly, the use of parabens continues to grow. It appears that some major cosmetic companies that joined the “paraben-free” craze are quietly formulating with them again, and there are three major reasons for this decision. The first reason is that contrary to junk science and half-truths, parabens are extremely safe and have a real and proven track record of safety. The second reason is that they are effective; and finally, they are cost-effective.

Preservatives being used more frequently in the United States include: phenoxyethanol, which usually is used as a solvent for parabens and in combination with the 1,2 diols; chlorphenesin; iodopropynyl butylcarbamate, despite the severe restrictions from the EU; and isothiazolinones. Since isothiazolinones are offered as both the 3:1 mixture of chloro to non-chlorinated forms for rinse-off products, and plain methylisothiazolinone for both leave-on and rinse-off applications, it is difficult to make a clear interpretation from the numbers. Many companies register only the chloro form rather than the mixture when using the commercial mixture.

Also growing rapidly are the “non-preservative” preservatives. These chemicals are not listed as permitted preservatives in the EU or Japan, so they are added for “other” reasons. They include caprylyl glycol, ethyl-hexylglycerin and penetylene glycol. All of these are used in combinations, usually with anti-fungal preservatives, to offer complete protection.

The preservative data registered with Health Canada also shows a significant increase in paraben use. Generally, the preservatives being used more frequently in the United States are also being used more frequently in Canada with a few exceptions: benzyl alcohol, potassium sorbate, iodopropynyl butylcarbamate, diazolidinyl urea and 2-bromo-2-nitro-1,3-diol. This last preservative is rarely used in the United States but remains popular in Europe; therefore, the increase in use of this preservative in Canada may be due to European imports. Finally “non-preservative” preservatives also have grown in Canada.

Preservatives on the Decline

Preservatives declining in use include imidazolidinyl urea, quaternium-15 and triclosan. Triclosan currently is under fire by NGOs, although its use as a cosmetic preservative is limited due to its activity against only a few Gram-positive bacteria and its insolubility in water. NGOs claim that triclosan causes antibiotic-resistant bacteria but this is not supported by scientific evidence.

Preservative/Allergen Correlation

It is useful to note that an increase or decrease in preservative use may be influenced by sensitization numbers issued by dermatologists, since sensitization and irritation are the most common safety issues with preservatives. The North American Contact Dermatitis Group published its last update in 2009.² This study reported data from some 4,454 patch-tested patients, including 65 chemicals in each test tray collected from 13 research centers across the United States. The preservatives used in the 2009 study and their reaction results are shown in Table 2.

Readers are reminded, however, that the volunteers involved in these sensitization tests are afflicted with pre-existing skin conditions. Thus they probably represent less than 1% of the general population and their reactions to preservatives overall would be much greater than in comparison with the general population. It will be several years before the next patch-test report is published since the data collection process is complicated, and it will be interesting to see the results of the next report. This author believes that sorbic acid, which was frequently used up until the late 1960s, and caprylyl glycol will be added to the test allergens.

Conclusion

Cosmetic marketing often uses terms such as paraben-free or preservative-free to sell products without considering how these trends may affect the cosmetics industry. These terms often are inspired by the latest NGO report claiming these raw materials to be unsafe. However, the present frequency of use reports show that cosmetic companies are quietly rejecting the fear promoted by NGOs and basing their product development strategies on science that supports the safety of these raw materials.

Cosmetics are safe. Preservatives are safe. Marketers must allow formulators to choose what is best to protect their products from contamination. Legislation in the United States such as the Safe Cosmetic Act of 2010 is introduced because NGOs continue to claim that some raw materials are unsafe—because cosmetic marketers continue to push formulations claiming to be free from these safe ingredients.

A final important observation here is the fact that such poor support for the FDA’s VCRP plays right into the hands of those promoting cosmetic products as being unsafe. Since voluntary compliance appears to not be working, the rationale is that the cosmetics industry needs mandatory oversight. Legislation in the United States such as the Safe Cosmetic Act of 2010 is introduced because NGOs continue to claim that some raw materials are unsafe because cosmetic marketers continue to push formulating without these safe ingredients; and because the cosmetic industry in the United States does not volunteer its information. The personal care industry’s inaction ultimately could end up causing it harm.

Acknowledgement: The author wishes to thank the cosmetic branches of the FDA, Health Canada and the North American Contact Dermatitis Group for supplying the raw data presented in this column.

References

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1. DC Steinberg, Voluntary Registration of Cosmetics and 2007 Frequency of Preservative Use, Cosm & Toil 123(10) 47–52 (2008)
   
2. Patch-test results, North American Contact Dermatitis Group 2005–2006, Dermatitis 20(3) (May/June 2009) 149–160