470 JOURNAL OF COSMETIC SCIENCE of a lake pigment is required for consistency in the cosmetic colorant labeling system between countries. CONCLUSION In this report, cosmetic colorants were categorized into three groups (synthetic, inor- ganic, and natural) and reviewed. It also presented an overview of the general properties of cosmetic colorants and a comparison of the differences in regulations between the EU, the United States, China, and Korea. Narrowing regulatory system gaps between countries is a key challenge facing the ­ cosmetic colorant industry. First, to ensure international consistency on safety and reg- ulation, a positive list of cosmetic colorants should be harmonized between countries. Especially if one country has banned a colorant used in cosmetics but other countries still permit its use, it will cause confusion among consumers. Furthermore, the ingredients listed on the positive list should be identified by their INCI names. The ingredient list of natural colorants is somewhat vaguely identified compared to that of synthetic colorants. In addition, the naming of chemical compounds in the specifications should be written in exact chemical names rather than ambiguous terms (e.g., higher sulfonated subsidiary colors). Second, generally accepted uniform specifications, standards, and methods should be adopted. Although a cosmetic colorant is included on the positive list, it may have dif- ferent structures because each country has set its own definition in its specification. The specification includes the definition, origin, manufacturing process, purity criteria, and so on. Additionally, it is recommended that the testing methods and procedures be har- monized to minimize the misinterpretation of test results. Lastly, natural colorants have presented stability concerns rather than safety issues before now. Rather than ­ limiting the types of natural colorants and regulating their use, encouraging manufacturers to be responsible for ensuring the safety of their products could be an alternative approach. This report ultimately aimed to provide a common understanding of cosmetic colorant regulations, and support manufacturers’ trading of cosmetics around the world. National regulatory authorities and manufacturers in each country should continue to promote international regulatory collaboration to develop the harmonization of cosmetic colorants.

Appendix List of colorants in cosmetic products No. Common Name a CI No. (salt form) b US Name c Korean Name a Class EUb China d United States b Korea a 1 CI 10006 Synthetic · Rinse-off products · Rinse-off products · Not listed · Not listed 2 Naphthol Green B CI 10020 Green 401 Synthetic · Not to be used in products applied on mucous membranes · Not to be used in products applied on mucous membranes · Not listed §2. Green 401 (CI 10020) · Not to be used in eye and lip products · Ba, Sr, Zr lake cannot be used 3 Naphthol Yellow S CI 10316 Ext. Yellow 7 Yellow 403 (1) Synthetic · Not to be used in eye products 1-naphthol≤0.2%: 2,4-dinitro-1-naphthol≤ 0.3% · Not to be used in eye products §74.2707a Ext. D&C Yellow No. 7 · Not to be used in eye and lip productsand §18. Yellow 403 (1) (CI 10316) · Not to be used in eye lip products 4 Hanza Yellow CI 11680 Yellow 401 Synthetic · Not to be used in products applied on mucous membranes · Not to be used in products applied on mucous membranes · Not listed §17. Yellow 401 (CI 11680) · Not to be used in eye and lip products · Ba, Sr, Zr lake cannot be used 5 CI 11710 Synthetic · Not to be used in products applied on mucous membranes · Not to be used in products applied on mucous membranes · Not listed · Not listed 6 Orange no. 401 CI 11725 Orange 401 Synthetic · Rinse-off products · Rinse-off products · Not listed §57. Orange 401 (CI 11725) · Not to be used in products applied on mucous membranes · Ba, Sr, Zr lake cannot be used 7 CI 11920 Synthetic - - · Not listed · Not listed 8 CI 12010 Synthetic · Not to be used in products applied on mucous membranes · Not to be used in products applied on mucous membranes · Not listed · Not listed