27 CFR §26.191
Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
At least 5 business days before shipment, each proprietor of a distilled spirits plant in Puerto Rico who intends to ship denatured spirits to the United States in containers larger than 5 gallons, and each person in Puerto Rico who intends to ship products made with denatured spirits to the United States in containers larger than 5 gallons shall notify the chemist of the Treasury of Puerto Rico of the intent to ship.