40 CFR §180.1021

1. (a)Copper is exempted from the requirement of a tolerance in cattle, meat; goat, meat; hog, meat; horse, meat; sheep, meat; milk, poultry, fat; poultry, meat; poultry, meat byproducts; egg, fish, shellfish, and irrigated crops when it results from the use of:
   1. (1)Copper sulfate as an algicide or herbicide in irrigation conveyance systems and lakes, ponds, reservoirs, or bodies of water in which fish or shellfish are cultivated.
   2. (2)Basic copper carbonate (malachite) as an algicide or herbicide in impounded and stagnant bodies of water
   3. (3)Copper triethanolamine and copper monoethanolamine as an algicide or herbicide in fish hatcheries, lakes, ponds, and reservoirs
   4. (4)Cuprous oxide bearing antifouling coatings for control of algae or other coatings for control of algae or other organisms on submerged concrete or other (irrigation) structures.
   5. (5)Copper oxide embedded in polymer emitter heads used in irrigation systems for root incursion prevention.
2. (b)The following copper compounds are exempt from the requirement of a tolerance when applied (primarily) as a fungicide to growing crops using good agricultural practices:
3. (c)Copper sulfate pentahydrate (CAS Reg. No. 7758-99-8) is exempt from the requirement of a tolerance when applied as a fungicide to growing crops or to raw agricultural commodities after harvest, and as a bactericide/fungicide in or on meat, fat and meat by-products of cattle, sheep, hogs, goats, horses and poultry, milk and eggs when applied as a bactericide/fungicide to animal premises and bedding.
4. (d)Copper (II) hydroxide (CAS Reg. No. 20427-59-2) is exempt from the requirement of a tolerance when applied to growing crops or to raw agricultural commodities as an inert ingredient (for pH control) in pesticide products.