Traditional preservatives have been in the news for the past couple of years, but in many cases, for all the wrong reasons. Environmental groups and regulators have taken aim at these important ingredients, especially parabens, basing their arguments on flimsy links to cancer. No wonder why there has been a renewed call for paraben-free cosmetic and personal care formulas. But how can chemists produce these products and, at the same time, ensure their safety? Inolex executives say they have an answer via their innovative chelating technology.

“The world of alternative preservatives is evolving,” explained Daniel Winn, PhD, director, personal care, Inolex Chemical. “Inolex is an expert in how to create paraben-free formulas.”

To overcome the weak fungistatic properties of glycols, which have good bacteriostatic properties, Inolex researchers turned to caprylhydroxamic acid (CHA), said to be an ideal organic acid, because it is effective at neutral pH and it has selective and powerful chelation for Fe2+ and Fe3+.Mold growth is reduced in iron-limited environments.

The first generation of materials from Inolex blended CHA with the glycols and the result was a broad product line that includes Spectrastat (CHA + caprylyl glycol), Spectrastat G (CHA + glyceryl caprylate) and Spectrastat E (CHA + ethylgexylglycerin). These blends debuted in 2008 and have been used by several companies in a wide range of leave-on skin care and prestige cosmetics.

Cost-Effective Solutions

But Inolex researchers realized that there was still a need for CHA blends using economical glycols for use in mass-market cosmetics and toiletries. This demand led to the creation last year of CHA blends based on cost effective aromatic glycols, such as phenoxyethanol, benzyl alcohol and phenylethyl alcohol.

More specifically, Inolex’s Phenostat combines CHA, phenoxyethanol and methylpropanediol. The recommended use level is 1%. The company notes that phenoxyethanol is a globally-approved preservative and remains consumer-acceptable in most markets. Methylpropanediol is a safe and widely used liquid diluent.

Benzostat includes CHA, benzyl alcohol and glycerin. Benzyl alcohol is a widely used fragrance ingredient and approved preservative. Benzostat’s recommended use level is also 1%.

Finally, new Aromastat contains CHA, phenylethyl alcohol and glycerin. Phenethyl alcohol is also a widely used fragrance ingredient and when incorporated into personal care products, it enables formulators to make preservative-free and paraben-free claims.

Phenostat, Benzostat and Aromastat are all recommended for products such as cleansing body washes, moisturizing lotions and baby wipes. Phenostat is also recommended for use in sun care products. All three are approved for use in the European Union, Japan, Canada and Australia.

Just as important, Inolex’s patent-pending, CHA-based systems enable formulators to make paraben-free, preservative-free, even biocide-free claims.

“We can offer formulators a wide range of premium and economical blends based on CHA technology,” explained Winn.“CHA is a novel chelating agent, that together with glycols, provides guaranteed, broad-spectrum performance.”