Conn. Agencies Regs. § 22-111j-4
All plant nutrients which are to be used in the production, manufacture, and distribution of fertilizer shall be registered with the Commissioner of Agriculture and shall be guaranteed by the manufacturer or distributor. Said guarantees shall be established on an elemental basis as prescribed by statute. All sources of such elements, so guaranteed, and proof of the availability of such elements shall be provided to the Commissioner upon his request. The minimum percentage which shall be acceptable to the Commissioner for registration are as follows: calcium (CA), 1.000%; magnesium (MG), 0.5000%; sulfur (S), 1.000%; boron (B), 0.0200%; chlorine (CL), 0.1000%; cobalt (CO), 0.0005%; copper (CU), 0.0500%; iron (FE), 0.1000%; manganese (MN), 0.0500%; molybdenum (MO), 0.0005%; sodium (NA), 0.1000%; zinc (ZN), 0.0500%.
Conn. Agencies Regs. § 22-111j-4