Relating to the age at which a person may purchase or possess nitrous oxide.

SB 666 raises the legal age to purchase or possess nitrous oxide from 18 to 21 years old in Texas. It makes selling nitrous oxide to anyone under 21 a state jail felony (with limited exceptions), while keeping existing rules for other volatile chemicals at age 18. Businesses must display bilingual signs stating the age restriction, and new defenses include parental supervision for minors or proof of age via Texas ID. This directly affects nitrous oxide sellers (like retail stores) and buyers aged 18-20, who will no longer legally purchase it after the law takes effect September 1, 2025.