Hair Coloring 152 Color fade can actually be an advantage for some consumers where after a few washing cycles there is more variation from fiber to fiber and the color appears lighter and more natural. However, it is generally a negative because the vibrant tones are lost, leaving a dull color and gray coverage may decrease. In addition, for lighter shades, fading of the dyes can lead to the appearance of warm tones from the natural hair color that has been lightened (off-tone). Color refreshers are now available in the market to combat wash fade by replacing some of the lost color. These are typically wash-in products applied to hair for several minutes and which are formulated with cationic direct dyes that give an immediate and strong color boost that will last for 5–10 shampoos. In addition, there are many shampoos and conditioners that claim to reduce wash fade usually because of ingredients that add a protective hydrophobic coating to the hair to retard color loss. For example, many new silicone technologies are being introduced to decrease the color fade.40 Safety and Regulatory Considerations As cosmetic products, hair dyes are regulated by global regulatory authorities like the US Food and Drug Administration (FDA), or the European Union Cosmetic Directive and its applicable scientific advisory board, the Scientific Committee on Consumer Products (SCCP). Hair dyes are one of the most thoroughly studied cosmetics—indeed one of the most studied consumer products— and there is an overwhelming amount of safety data on hair dyes.41 As is the case with certain foods or drugs, hair dyes can cause allergic reactions in a very few individuals. Allergic reactions to hair dyes are known but extremely rare, particularly in light of the daily global use of millions of hair colorants. To reduce the risks, all hair dye products are required to carry allergy warning labels, making users aware of the potential allergy risk. Consumers are advised to conduct a skin sensitivity test 48 hours before each hair color application. Professional hairdressers should follow key occupational safety measures, and wear protective gloves during preparation, application, and rinsing of hair colorants.42