Iowa Code § 126.22: Nitrous oxide.

1. Any person who possesses nitrous oxide or any substance containing nitrous oxide, with the intent to breathe, inhale, or ingest for the purpose of causing a condition of intoxication, elation, euphoria, dizziness, stupefaction, or dulling of the senses, or who knowingly and with the intent to do so is under the influence of nitrous oxide or any material containing nitrous oxide, is guilty of a serious misdemeanor. This subsection shall not apply to a person who is under the influence of nitrous oxide or any material containing nitrous oxide for the purpose of medical, surgical, or dental care by a person duly licensed to administer such an agent.

2. Any person who distributes nitrous oxide, or possesses nitrous oxide with intent to distribute to any other person, if such distribution is with the intent to induce unlawful inhaling of the substance or is with the knowledge that the other person will unlawfully inhale the substance, is guilty of a serious misdemeanor.