Chapter 43: FDA says Copper Sulfate is “GRAS”: Generally Recognized as Safe
Copper sulfate is defined in law as “generally recognized as safe”, specifically allowed for use as a “nutritional supplement”.
I am not listing this as proof that copper is safe. This is only evidence of what US law says regarding the subject. For those who take what the government says far too seriously, they should seriously consider this:
https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=184.1261
https://www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-184/subpart-B/section-184.1261
https://codes.findlaw.com/cfr/title-21-food-and-drugs/cfr-sect-21-184-1261.html/
[Code of Federal Regulations]
[Title 21, Volume 3]
[Revised as of April 1, 2020]
[CITE: 21CFR184.1261]
TITLE 21–FOOD AND DRUGS
CHAPTER I–FOOD AND DRUG ADMINISTRATION
DEPARTMENT OF HEALTH AND HUMAN SERVICES
SUBCHAPTER B – FOOD FOR HUMAN CONSUMPTION (CONTINUED)
PART 184 — DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE
Subpart B – Listing of Specific Substances Affirmed as GRAS
Sec. 184.1261 Copper sulfate.
(a) Copper sulfate (cupric sulfate, CuSO4-5 H2O, CAS Reg. No. 7758-99-8) usually is used in the pentahydrate form. This form occurs as large, deep blue or ultramarine, triclinic crystals; as blue granules, or as a light blue powder. The ingredient is prepared by the reaction of sulfuric acid with cupric oxide or with copper metal.
(b) The ingredient must be of a purity suitable for its intended use.
(c) In accordance with § 184.1(b)(1), the ingredient is used in food with no limitation other than current good manufacturing practice. The affirmation of this ingredient as generally recognized as safe (GRAS) as a direct human food ingredient is based upon the following current good manufacturing practice conditions of use:
(1) The ingredient is used as a nutrient supplement as defined in § 170.3(o)(20) of this chapter and as a processing aid as defined in § 170.3(o)(24) of this chapter.
(2) The ingredient is used in food at levels not to exceed current good manufacturing practice. Copper sulfate may be used in infant formula in accordance with section 412(g) of the Federal Food, Drug, and Cosmetic Act (the Act) or with regulations promulgated under section 412(a)(2) of the Act.
(d) Prior sanctions for this ingredient different from the uses established in this section do not exist or have been waived.
[49 FR 24119, June 12, 1984, as amended at 73 FR 8607, Feb. 14, 2008; 76 FR 59249, Sept. 26, 2011]
(20) Nutrient supplements : Substances which are necessary for the body’s nutritional and metabolic processes.
(24) Processing aids : Substances used as manufacturing aids to enhance the appeal or utility of a food or food component, including clarifying agents, clouding agents, catalysts, flocculents, filter aids, and crystallization inhibitors, etc.