In a recent trade journal article, Katerina Steventon Ph.D., talked about new studies done on preservatives that are commonly used in skincare products. As I shared in my article, Parabens and Preservatives that may be found here: http://greatnewskin.com/pages/parabens-and-preservatives

Product preservation is required for global entry sales to consumers, and for the safety of us all, from a health standpoint. Within the industry, and amongst consumers, there is confusion and controversy.

Dr. Steventon cites a recent study done by the Danish Environmental Protection Agency, to evaluate the risks of preservatives in cosmetic products. It’s assessment of 53 preservatives showed an allergen risk from three: DMDM hydantoin, imidazolidinyl urea and thimerosal. On a global level, mainly driven by consumer demand, the use of parabens in products is down, and phenoxyethanol is now the highest use alternative. 
Denmark has lobbied for the preservative, methylisothiazolinone (MI) a synthetic preservative biocide that is used in sun and skincare products, to be banned. In the US, we have seen an alarming trend in skincare products, particularly Anti Aging products of the use of Sodium Hydroxide and Aluminum Hydroxide, which is a lye base.
https://greatnewskin-us.myshopify.com/admin/blogs/6281443/articles/17827099

Sodium Hydroxide (and Aluminum Hydroxide) use in Anti Aging and Skin Care product ingredients is an alarming new trend. A lye base:

http://en.wikipedia.org/wiki/Lye  and highly alkaline. Healthy skin pH is 4-5.5 on average, nor do bacteria like acidic environments.

Wikipedia says this:

A lye is a liquid obtained by leaching ashes (containing largely potassium carbonate or "potash"), or a strong alkali which is highly soluble in water producing caustic basic solutions. "Lye" is commonly the alternative name of sodium hydroxide (NaOH) or historically potassium hydroxide(KOH).

Some of the products containing Sodium Hydroxide include:

Murad Advanced Active Radiance, SkinCeuticals A.G.E. Eye Complex, VERSO Day Cream, Caudalie Anti-Wrinkle Defense Serum & Cru, Caudalie Premier The Eye Cream, Proactiv Complexion Perfecting Hydrator, Algenist Anti-Aging Eye & Genius Cream, and Clarisonic Opal Anti-Aging Sea Serum, Epionce Melanocyte Pigment Perfecting Serum, and Epionce Facial Lotion.

http://greatnewskin.com/blogs/news/tagged/anti-aging-product-ing