Silver

The Food and Drug Administration (FDA) lists Silver as a color additive exempt from certification. It may be safely used for coloring fingernail polish at a level not to exceed 1% of the final product.

Cosmetic Ingredient Review (CIR) has deferred evaluation of this ingredient because the safety has been assessed by FDA. This deferral of review is according to the provisions of the CIR Procedures.All color additives used in foods, drugs and cosmetics in the United States must be approved by FDA and listed in the Code of Federal Regulations. In some cases, FDA requires that each batch of color produced for use in regulated products can be used only if it is certified by the agency to meet strict specifications. FDA maintains a laboratory especially for this purpose and color manufacturers must pay a fee to support this activity. FDA only approves colors after extensive review of all safety data and publication of the basis for its approval in the Federal Register.

You can find out more about FDA regulation of colors at:
http://www.cfsan.fda.gov/~dms/cos-col.html

Link to FDA Code of Federal Regulations for Silver
http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRS...

Silver is listed as CI 77820 in the Cosmetics Directive of the European Union and may be used as a coloring agent in all cosmetics and personal care products. When used in cosmetics and personal care products in Europe, Silver must be called CI 77820.
Link to the EU Cosmetics Directive: http://ec.europa.eu/enterprise/cosmetics/html/consolidated_d...

You can learn more about the regulation and labeling of colors at: http://www.personalcarecouncil.org/Content/NavigationMenu/Co...

Health Canada permits the use of Silver and its salts in cosmetics and personal care products. Silver and its salts are restricted to concentrations of 0.04% or less in mouthwashes. Cosmetics and personal care products containing Silver or silver salts must include the following statement on the label: "This product contains silver and/or silver salts, avoid contact with broken or abraded skin."
See the Health Canada website for more information.
http://www.hc-sc.gc.ca/cps-spc/person/cosmet/hotlist-liste_3...