TONY O’LENICK
Siltech L.L.C., 1625 Lakes Parkway, Suite N., Lawrenceville, GA 30043, USA

Abstract

Cyclomethicone as a class of compounds and D4 and D5 in particular have been a topic discussed, debated and regulated in recent years. The important regulatory status references are given in Table 1. D4 effectively is not used in the personal care industry and D5 is under increased scrutiny. It also must be clearly understood that D5 currently is acceptable to use in a variety of personal care products and any replacement is one that is done by choice and not regulation. Since 2010, there have been a number of “replacements” suggested for use in our industry. These “replacements” need not only to provide the aesthetic effects of D5, but also do so in a cost effective way, while not causing any unintended problems like flammability, irritation or environmental problems. This article will explore the functionality of D5 in formulations, and the various “replacements” that have been suggested. The formulator must bring a discerning mind asking, “Why use 5 in formulation and what if any replacements can efficiently be made. This article is a follow up to the article 1 by O’Lenick and Vergani.

Regulatory Opinions

There are a number of applications in which a dry skin feel is important. Cyclomethicone compounds are commonly used in cosmetic products to provide a solvent that feels dry on the skin. The INCI name Cyclomethicone refers to a family of cyclic dimethyl siloxanes that includes Cyclotetrasiloxane (D₄), Cyclopentasiloxane (D₅) , and Cyclohexasiloxane (D₆), a family that has come under increased environmental scrutiny in recent years.

Key areas where this family of materials is used include antiperspirants, color cosmetics and as a base solvent to blend with fragrance oils and perfume oils. Cyclomethicone is a clear, odorless silicone. It leaves a silky-smooth feel when applied to the skin and does so at a low cost and is not flammable.

Formulator tip

The formulator must ask, why is cyclomethicone used in formulations? The answer must always be functional, not ... ...