R.I. Gen. Laws § 21-22-3: Metallic salts — Mineral acids.

All vinegars shall be without any metallic salts of arsenic, lead, copper, tin, or zinc, or any sulphuric, hydrochloric, nitric, or other mineral acid injurious to health; and if any vinegar contains any metallic salts of arsenic, lead, copper, tin, or zinc, or any sulphuric, hydrochloric, nitric, or other mineral acid injurious to health, it shall be deemed to be adulterated within the meaning of this chapter.