LIFESTYLE COSMETICS
A formulator’s guide to working with colourants
Kelly Dobos - University of Cincinnati, USA
Colour provides crucial information about the world around us. Colour also plays a significant role in cosmetics and personal care products that extends beyond the obvious example of makeup. Colour can be important in differentiating products from one another on shelf, signaling efficacy, or reinforcing hero ingredients and fragrance. A change in colour can also signal the
degradation of raw materials, which can negatively impact product performance and consumer acceptability. There is considerable art, as well as science, in developing products that meet consumer demand for attractive and functional cosmetics. While there are additional specialty
colourants (that include aluminum powder and luminescent zinc sulfide with their own unique regulatory and end-use limitations), the focus of this article is the use of the three broad categories colourants: dyes, pigments and pearlescent effect pigments.
The basic
principles of working with these classes of colourants can be applied broadly to many types of cosmetic products.
Regulatory considerations Colour additives used in cosmetics and personal care products are regulated in every country and region around the world. To ensure compliance and avoid regulatory enforcement actions that can be damaging to a brand’s reputation, it is imperative to review the regulations in every market in which products will be produced and sold prior to beginning product development work. The lists of permitted colours, as well
as percentage and use area (eye, lips, etc.) restrictions, may vary considerably and colourant nomenclature used for labeling of finished goods also differ between regions. The European Union (EU) utilizes the Colour Index number, a Japanese name is used in Japan, and the United States has a unique nomenclature system applied to synthetic organic colour additives. The United States also has a certification
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requirement for synthetic organic colour additives, which requires the material to pass testing at the US Food & Drug
Administration’s own laboratories prior to use in cosmetics and
personal care products. Once the colour additive
passes testing, a certification number is issued for the batch that
is distinct from the lot number. The use of colour additives must be accurately accounted for in manufacturing with the certification number of the colour additive recorded in the batch record for each lot of finished goods. Other chemical regulations may also
affect the use colour additives. Examples include the EU’s chemical legislation know as Registration, Evaluation and Authorization of Chemicals (REACH) and the State of California’s Proposition 65 in the United States.
Colour definitions We can characterize and categorize colour additives in a variety of ways by describing their chemistry, solubility, performance or regulatory status. So, before discussing the application of colour additives, it is necessary to review some definitions.
Colourant A collective term for all soluble or insoluble colouring agents, as well as insoluble pigments that produce a colour effect through their distribution or diffusion.
Colour additive As defined by the United States Food and Drug Administration, a colour additive is any substance that imparts colour to a food, drug, cosmetic or to the human body.
Dye A colourant that is soluble in the medium in which it is used and produce transparent colour when dissolved. Dyes used in cosmetics and personal care products primarily water soluble, however there are a few oil-soluble dyes. Chemistry and performance differ for
applications in textile and hair colouring that are not included in the scope of this article.
January 2024 PERSONAL CARE
Colour Colour is a perceived phenomenon of light’s interaction with an object. Colour is also referred to as hue. Descriptors for hue are terms like red, orange, yellow, green, blue, indigo and violet. However, there are many degrees of
differentiation between these colours. For example, red can be yellow shade or blue shade. White, black, and shades of grey are also considered colours for our purposes.
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