21 C.F.R. § 73.2125 – Potassium sodium copper chlorophyllin (chlorophyllin-copper complex).

(a) Identity and specifications. The color additive potassium sodium copper chlorophyllin shall conform in identity and specifications to the requirements of § 73.1125(a)(1) and (b).
(b) Uses and restrictions. Potassium sodium copper chlorophyllin may be safely used for coloring dentifrices that are cosmetics subject to the following conditions:
1. (1) It shall not be used at a level in excess of 0.1 percent.
2. (2) It may be used only in combination with the following substances:
  Water. Glycerin. Sodium carboxymethylcellulose. Tetrasodium pyrophosphate. Sorbitol. Magnesium phosphate, tribasic. Calcium carbonate. Calcium phosphate, dibasic. Sodium N-lauroyl sarcosinate. Artificial sweeteners that are generally recognized as safe or that are authorized under subchapter B of this chapter. Flavors that are generally recognized as safe or that are authorized under subchapter B of this chapter. Preservatives that are generally recognized as safe or that are authorized under subchapter B of this chapter.
(c) Labeling. The label of the color additive shall conform to the requirements of § 70.25 of this chapter.
(d) Exemption from certification. Certification of this color additive is not necessary for the protection of the public health and therefore batches thereof are exempt from the certification requirements of section 721(c) of the act.